Sunday, July 12, 2009

MOTORCYCLE HISTORY



The first motorcycle in history was produced in 1885 by German inventors Gottlieb Daimler and Wilhelm Maybach It was called a riding car. However, history shows us that in 1967, Sylvester Howard Roper of Roxbury, Massachusetts built a steam propulsion motorcycle. In 1876, Otto produced the first "Four-Stroke Internal-Combustion Engine".

The first motorcycle that went on sale was the Hildebrand & Wolfmüller in 1894. The "Indian" wad the largest motorcycle manufacturer prior to World War 1. Over time different motorcycle manufacturers would dominate the market from Harley Davidson to BSA Group to the powerful Japanese manufacturers that mostly dominate the market these days.

In 1946, Soichiro Honda founds the Honda Technical Research Insitute. By 1947, Honda has produced its first motorcycle, the 98cc, 2-cycle Dream.

The Ducati Family with investors founded the Società Radio Brevetti Ducati in Bologna. Originally they manufactured industrial components for radio transmissions. By 1946, Ducati introduced a 4-stroke 48cc clip-on engine for bicycles. And in 1952, the futuristic Cruiser 175cc, with automatic transmission and electric starter.

Yamaha: Founded by Torakusu Yamaha in 1888 originally as Yamaha Musical Instrument Company. After the war, Yamaha expanded into Motorcycles. The first was the 125cc, single cylinder two-stroke YA-1 Motorcycle.

1902: First Triumph motorcycle is produced. It uses a single-cylinder Belgian Minerva engine. It is fitted onto a bicycle frame.

How does Motorcycle Engine Work


A while ago, I wondered "how does an engine *really* work". I wasn't just thinking of explosion in cylinders pushing pistons up and down. I was thinking of the little details. This file is a tidied up version of my random notes and questions.

If you want more detail, then grab a copy of the book Vehicle and Engine Technology from Amazon. It tells you how engines, carburettors, chassis, tyres etc work. It's where I learned all this stuff from, and it's probably the only book on the subject I'll ever need.
How does an engine work

We want the engine to turn the back wheel. Or, more practically, to turn the gearbox since we want the bike to move both a very slow speeds and very fast speeds. The range of engine speeds available is roughly 1000 to 10,000 rpm which is a factor of ten. We want to ride a motorbike at anything from 1 to 100mph which is a factor of 100. So, we need a gearbox to provide a suitable range of gears. The engine drives the gearbox which drives the wheel. How do we get rotational motion from the engine?

We do this by a piston which provides periodic linear motion, connected by a con-rod to a crankshaft which turns the linear motion into rotation. The piston experiences a downward force on the ignition stage, which increases its monentum. The crankshaft acts as a flywheel which moves the piston through the other three stages (exhaust, intake and compression).

What affects the force on the piston when we ignite the fuel/air mixture?

* Combustion is not instantaneous. A flame spreads from the spark plug across the cylinder. This takes a significant amount of time. Remember that an engine running at 10,000 rpm completes one revolution in 0.006 secs.
* Combustion isn't always complete. The fuel/air mixture might now have completely burned by the time it gets punted out of the exhaust port.
* The amount of fuel/air mixture ignited. We can get more energy in each explosion by having more fuel and oxygen molecules in the cylinder to react together. This is why turbos and supercharges make an engine more powerful - they squeeze more fuel and air molecules into the cylinder. Nitros add an oxygen-rich chemical into the cylinder, which means we can burn more fuel.
* The fuel/air ratio. Different proportions of fuel and air will affect combustion. Let's look more at petrol first ...

The Future of Harley-Davidson...




With all these positives, what can be bad? Indian and Harley-Davidson.

World wide sales in the retro type cruiser are again starting to go down. Sales seem only to be strong in the USA. Indian Motorcycle has closed up shop, yet again, due to slow sales of the cruiser models. Harley-Davidson is still ignoring a huge market (younger crowd) and is still continuing to design models that appeal to fewer each year at prices even fewer can afford. With HD's 2004 "major" updates really being a "minor" change, has HD missed its mark again? Will Harley-Davidson be the next to go? (Sorry Harley riders)
Honda is now selling the Honda Rune, a style that is very impressive to see with your own eyes. This is a bike that looks like Harley-Davidson will make 20 years from now. Not only is the

Honda Rune a big problem for HD, but the Vulcan 2000, Triumph Rocket III and even the Kawasaki/Suzuki Mean Streak are as well in the future design department. It used to be everyone copied HDs style, it was "the" cruiser look. Now you can have a sea of HD bikes, and if one of the above bikes shows up, it just gets noticed more.
o, what is Harley gonna do? They made the V-Rod. Beautiful lines, great engine, fuel injected, sporty looking... But... it doesn't sound like a Harley, doesn't look like a Harley, infact, it looks like a "Japanese" bike! The V-Rod as much an"outsider" to the HD community as a Buell, horrible shame that is too...

So, does Harley-Davidson keep making retro looking cruisers with very old and outdated technology so they have the look and sound? OR do they gamble on newer designs like the V-Rod? With an average consumer age of 46+, and thus you see the problems facing Harley-Davidson's future today.

Revealed at 2003 Milan Motorcycle Expo: Kawasaki ZZR-X




Probably the most radical machine of the show has yet to turn a wheel under its own power. The ZZR-X is Kawasaki's forward-looking concept bike
that combines advanced technology, super-sport potential and touring capability. "This is the ultimate high-speed tourer,” reads the Kawasaki press material. “The future of supersport touring."
The ZZR-X features hub-mounted steering that uses a two-pronged aluminum swingarm actuating a shock absorber instead of the ubiquitous telescopic fork. Handlebars sweep through the area that looks like a fuel tank; the actual tank is placed near the center of the bike. Perimeter rim-mounted disc brakes are fitted to both wheels.

Touring amenities include a shaft drive hidden inside the aluminum rear swingarm, an adjustable-rake, flip-up windscreen and a large storage area in front of the seat. Kawasaki doesn’t mention any details about the ZZR-X’s engine, but it’s safe to say there will be ample power if the bike is ever built. The rear seat cowl flips up into a backrest, probably to keep the passenger from flying off at 186 mph."

Revealed at 2003 The Tokyo Motorshow : Suzuki G-Strider


Suzuki presented their G-Strider concept motorcycle, a cross between a scooter and a motorcycle. The two wheeler is powered by a 916 cc engine with automatic transmission.

Revealed at 2003 The Tokyo Motorshow : KTM


The new 990RC8 is a streetfighter type, with a 75° V2, 999.8 cc engine.

The seat is the fuel tank, giving this 175 kg (385 pounds) motorcycle a low center of gravity.

Top speed: 280 kilometers per hour ( 174 miles per hour)

Car manufacturers to make motorcycles?


Dodge introduced its Tomahawk V-10, 8.3-liter (505 cubic inch) concept motorcycle at the North American International Auto Show in Detroit on January 6, 2003. The superbike features independent four-wheel suspension, and its engine, borrowed from the Viper sports car, can propel the Tomahawk at speeds of nearly 400 mph [sic], according to Dodge. REUTERS/Rebecca Cook

The 1,500-pound Tomahawk can reach 60 miles an hour in about 2.5 seconds, and has a theoretical top speed of 300 mph. Each pair of wheels is separated by a few inches and each wheel has an independent suspension. [Chrysler Chief Operating Officer Wolfgang] Bernhard said four wheels were necessary to handle the power from the engine.… Chrysler executives said while the chrome-draped Tomahawk was outlandish, they were seriously considering whether to build a few hundred at a price of at least $250,000 each.


The Evolution has already begun...

Hybrid Gas/Electic Motorcycles?


We all know that a motorcycle is not only fun but cheap to own over other types of vechiles. With cars evolving into Hybrid (Gas/Electric), Hdrogen and fully Electric vechiles it wouldn't be long before motorcycles would follow. Those types of vechiles are getting great fuel milage and even better than a lot of motorcycles! (e.g. Honda Insight* 70mpg).

Diesel Motorcycles?


Not to be outdone in the engine development area, the US Army has a Kawasaki KLR650 that runs on Diesel fuel rather than normal gasoline! With a range of 120 miles per gallon the bike develops 33ftlb of torque and has a top speed of 85 MPH.

Electric Motorcycles



So, does that mean motorcycles will be going electric? It is quite possible

That all depends, there are positives and negatives (of course) of anything new over something old. The internal combustion engine has been around for more than 100 years. We have pretty much done everything we can with the basic design. The biggest reason we haven't "evolved" to another type of engine (electric/hydrogen/ect) is money (or the loss of) from the oil companies. Oil (as if you didn't know already) companies make Billions of dollars an hour worldwide, they don't want to give that up.

Electric engines offer advantages that could never be offered by an Internal Combustion engine such as:

- There is almost no noise at all.
- No vibration at all.
- Total Linear power availability.
- Zero moving parts.

Imageing cruising down the road, all you hear if the sounds around you, the wind on your face and nothing disturbing that. Not even virbration gets in the way (at any speed) of this feeling that is like flying. With a twist of the throttle you can go from 0 to 100mph in one gear if you want to with no hesitation, stuttering or loss of power anywhere, a perfect power curve.

As with the horse and buggie, we will all be sad to see them go. The Film camera industry is going though the same drastic change with Digital camera's. I own 9 professional SLR film cameras and don't want a Digital, I enjoy film and the process of taking a photo on film. To me that is what photography is all about and I don't want to change to digital at all. Some of you will be in the same boat when it is time for the internal combustion engine to leave the motorcycle and electric engines are all the rage. For you, you should hang on to those old outdated motorcycles then and enjoy it while you can. Personally I dread the day a roll of film costs $20 and developing is scarce, and you have to drive 20 miles out of the way to find it... But that is life and on a positive note, the world didn't end when we gave up a real horse for the iron horse (car)



The Distant Future..


Unfortunately, I don't know who made this image in photoshop, but it gives a good idea what a "retro" hover bike might just look like!

What goes into petrol?

Petrol contain mostly hydrocarbons. Hydrocarbons are basically anything which contain carbon atoms and hydrogen atoms. They're useful as a fuel, because a carbon atom can combine with two oxygen atoms to make carbon dioxide, and two hydrogens can comine with an oxygen to make water (H2O). Actually, as well as the carbon dioxide reaction, you get get a single carbon reacting with a single oxygen to make carbon monoxide (CO). This can then go on to react with more oxygen to make carbon dioxide. All these reactions release energy, which is what makes our piston move downwards.

Petrol is a mixture of about 500 different hydrocarbons, which contain between 3 and 12 carbon atoms. These hydrocarbons are liquid (obviously, since petrol is liquid) and they boil between 30 and 220 degree celcius. So, on a hot day the smallest molecules are going to start evaporating off if they're not in a sealed container.

Hydrocarbons are either saturated (only contain single bonds) or unsaturated (contains at least one double bond). Saturated hydrocarbons tend to burn cleanly, whereas unsaturated hydrocarbons burn smokily and are unstable.

Now, you want to get the biggest possible bang out of your fuel/air mixture, and you can do this by compressing it before igniting it. This pushes all of the fuel and air molecules closer together. A compression ratio of 6:1 gives 25% efficiency, whereas raising it to 12:1 gives 35% efficiency.

However, when you compress the mixture it gets hotter - up to 600 degrees celcius in a running engine.. If you compress it too much, it'll get hot enough to ignite itself, which is bad! If this happens in a running engine, it's called knocking or preignition and it can damage your pistons. Of course, if the engine is hot to start with, it'll heat up the mixture and make preignition more likely. We'll return to this in a minute.

So, the efficiency of your engine is related to the compression ratio, which is how much you squish the fuel air mixture before igniting it. The fuel/air mixture gets sucked into the cylinder on the intake stroke when the inlet value is open. Then it gets squished during the compression stoke, until the piston reaches its highest point. If there is 400 cubic centimetres above the piston at it's lowest point, but only 100cc at it's highest point then you have a compression ratio of 4:1. A real engine would have a compression ratios of something like 12:1.

We'd ideally want to have the compression ratio as high as possible, but we've seen that that'll cause the fuel/air mixture to ignite early (before the spark plug has sparked) and damage our engine. So, we look for some magic ingredient to stop this happening.

One such magic ingredient is Tetra-ethyl lead, which gives leaded fuel it's name. It reduces the tendency of the mixture to preignite. Unfortunately, it's bad for the environment and has been phased out in the UK. TEL acts to lubricate the exhaust value, so there's some concern that switching to unleaded fuel can lead to the exhaust valve being lubricated less.

Another problem with using tetra-ethyl lead (TEL) is that it would eventually gum up the engine and exhaust with lead, so you also have to add scavengers to the petrol. Scavengers are chemicals which react with the lead to make a volatile chemical which can pass out of the exhaust. An example would be lead halide salts.

It's worth noting that petrol usually contains some Sulphur before it gets refined. Sulphur defeats the anti-knock properties of TEL and so has to be removed. It's hard to remove it all though, and the sulphur which is left in the fuel reacts with air to form sulphur dioxide. The sulphur dioxide gets into the atmosphere via your exhaust and dissolves in water to form sulphuric acid - causing acid rain.

Fuel/air ratio

The carburettor controls the fuel/air mixture on a motorbike, and you often hear 'lean' and 'rich' being used to describe the fuel/air mixture. Let's look at what effect this ratio has on the engine.

Firstly, there's a theoretically optimal fuel/air mixture. This is called the stoichiometric mass/volume and it tells you how much air (ie. oxygen) you need to completely burn an amount of fuel. If you have less air than this, the mixture is rich. If you have too much air, the mixture is lean. You can look at it in terms of fuel. Too much fuel gives a rich mixture, too little gives a lean mixture.

The stoichiometric mass is related to the carbon/hydrogren ratio in your fuel. This makes sense, since each carbon atom needs two oxygen atoms to make CO2, and each hydrogren needs on average half an oxygen atom. So you can presumably just add up the number of carbon and hydrogen atoms and do a bit of maths to work out how many oxygen atoms you're going to need.

If you have the 'perfect' amount of oxygen for your petrol you can expect to get about 45 mega-joules of energy for every kilogram of petrol you've got. However, engines aren't perfectly efficient. For a start, to get the maximum amount of work out of the explosion, you'd have to let the gases expand until they've cooled down to the surrounding air temperature (look up Carnot cycles somewhere). In a real engine, the gases only get to expand as long as the piston is moving down. When the exhaust port opens, and the piston moves up to punt the exhaust gases out, the gases are still hot. That's why the exhaust pipe gets hot! A normal engine has an efficiency of about 20-40%, so it only gets 20-40% of the theoretical maximum amount of energy out of each explosion. The rest of the energy goes to warm up the engine coolant, the exhaust and the engine's surroundings.

All these hot exhaust gases go out of the cylinder, passing by the exhaust value. This makes the exhaust value pretty hot - up to 300 degrees celcius. Because of this, the exhaust value takes more of a hammering than the inlet valve, since the gases passing into the cylinder are at air temperature.

Apparently, for petrol you get stoichiometric combustion (that's complete combustion) when you have a fuel/air ratio of 1:15 (that's 15 parts of fuel to one part of air). You can get more power out of your engine by running a richer mixture of 13:1, but you'll be producing some partly burned fuel leading to smoky exhaust and a gunky engine. You get maximum thermal efficiency (most energy for a given amount of fuel?) when you have a lean mixture such as 17:1.

Let's look at what happens when the spark plug fires when you're running a lean mixture. There's less fuel molecules to go around, so the flame moves across the cylinder more slowly. This leaves more heat in the cylinder walls and cylinder head, which can lead to overheating. If the fuel/air mixture is very lean, then the flame can still be present when the inlet valve opens, which causes backfire!

If you've got a compression ratio of 12:1, with an engine speed of 1500rpm the flame will move across the cylinder at something like 15 meters per second.

As the engine speed increases, there's less time for the mixture to burn completely. An engine running at 1000rpm spends 0.06 secs in each cycle, which drops to 0.006 secs when it's running at 10,000rpm. One way to combat this drop in available burning time is to fire the spark plug a bit earlier when the engine is running fast - this is called the spark advance. If you increase the spark advance too much, it can cause knocking. However, if the engine is running fast then there's less time for reactions to occur on front of the flame front, which tends to decrease the chance of knocking.

Mechanical aspects of the engine

Engines are made from metal, because it's one of the few materials which can withstand the forces of the explosions, withstand the high temperatures and which can be made into the right shapes. The cylinder is made of metal. The piston and piston rings are made of metal. What stops this from scraping against each other in a nasty way?

The answer is oil. If you've got two metal surfaces rubbing against each other you need at least a thin layer of oil between them. If you run out of oil, or the oil film breaks at some place in your engine, the metal will rub together and get hot very quickly, potentially welding themselves together.

Why is oil good for this purpose? Most obvious, it's slidy. If you have two metal surfaces sliding against each other, then putting a layer of oil between them will decrease the friction.

What is oil made from? What makes it slidy? Long molecules? Why doesn't water work?

It has to be stable at temperature - can't decompose quickly.

What do the different ratings mean?

Piston rings to scrape the oil, block the explosion from getting down past the piston.

What does oil encounter during its lifetime (cold start, hot operating -- changes in viscosity).

If you use different metals when building an engine, you'd better be sure that they expand at roughly the same rate. If you make the piston from metal which expands faster (as the temperature increases) than the metal which the cylinder is made of, you'll have problems.

If you've got a rotating shaft, you need to support the two ends of it somehow. The two ends get supported in bearings (since they bear the load) in the engine case. A bearing is just a specially chosen material which reduces the friction between the parts - such as brass. You still need oil though.

Carburettors

The carburettor is the bit of the motorbike which mixes the fuel with air. The fuel comes the tank, through a fuel tap which lets you turn the fuel on or off, then into the carburettor. Normally, we leave it up to gravity to get the fuel from the tank into the carburettor - we don't need to pump it. This wouldn't work in an aeroplane which has to fly upside down, but bikes spend most of their life right-way-up so it works fine. The air is sucked in from the outside world, and passes through an air cleaner before reaching the carburettor. There's a few different types of air cleaner, but their purpose is the same. They remove grit, dust and other undesirable gunk from the air. You don't want little bits of grit flying into your engine where they'd cause havoc.

The carburettor has its own little reserve of fuel called the float chamber. This work in the same way as a toilet cistern. When the fuel level drops, a value is opened which lets more fuel in. When the fuel level is high enough, the valve closes. You can get an idea of how much fuel is stored in the float chamber by turning the fuel tap off while the bike is still running. It'll keep running for a minute or so.

The main purpose of the carburettor is to 'spray' the fuel into the air stream which passes through the carburettor. This creates a very fine mist, so that each bit of fuel is surrounded by lots of air which it can react with once it reaches the cylinder. It's no good having big blobs of fuel, because only the fuel on the surface will be exposed to oxygen.

Let's look at how the carburettor sprays the fuel into the air. There's a fairly wide passage runs through the carburettor which is where the air passes through. We make a little hole in the side of this passage, and connect it to the float chamber. The idea is that the passing air will suck the fuel out of the hole, and it'll then mix with the air.

We can make this work much better if we make the air passage narrow before it reaches the hole, and then widen afterwards. This creates a pressure difference (the Venturi effect) which acts to suck the fuel out into the air stream.

Clearly, the size of the hole is going to have a big effect on the resulting fuel/air mixture, so we use a carburettor jet. A jet is like a screw with a hole running down the middle of it. You screw the jet into the carburettor body, and the fuel goes up through the hole in the middle. You can buy jets with different sizes of hole if you want to change your fuel/air mixture.

There's a problem with this description though. There's not yet any way for the rider of the bike to control the fuel/air mixture. That's going to be a problem, because the rider isn't going to be happy with an engine which only runs at one speed. We can introduce speed control by arranging for a metal needle to sit above the jet. We can slow the engine down by moving the needle down, so that it partially blocks the hole in the jet. This throttles the fuel supply, and so it's known as the throttle control. The right-hand grip on a motorbike simply controls the height of the needle. When you're at full throttle, the needle is totally out of the jet. When you're going very slowly, the needle will be blocking the jet more.

So, that's the a pretty simple carburettor. The people who first built these things pretty quickly realized that they weren't perfect. For a start, they didn't work very well if the engine was running slowly. If the engine is running slowly, the piston is sucking air in at a relatively slow rate. If the air is moving past our jet very slowly, it doesn't suck out much fuel so we end up with an overly lean mixture. We can fix this problem by putting a second, larger, hole in the carburettor called the pilot jet. This is only operational when the engine is running slowly. It's larger size ensures that enough fuel is mixed in, even at slow speeds. At higher speeds, it's not used.

So, what can go wrong with carburettors? Since they've got lots of very small fuel passages, they can get blocked quite easily. That's why you have a fuel filter (usually in the fuel tap). That's also why it's a bad idea to run the bike with very little fuel. Chances are, you've got little bits of sediment in your fuel tank which have sunk to the bottom. If they get into the carburettor, everything is going to stop. You'll also get problems if the fuel leaves behind any residue inside the carburettor. This gums up the insides of the carb, and you need pretty noxious cleaning fluids to get rid of it.

If it's a cold day then starting the bike can be difficult. If the walls of the carburettor and cylinder inlets are cold, then the fuel will condense on the walls. The same thing happens if you breath out on a cold window - the water vapour in your breath condenses on the cold surface. If your fuel is all condensing before it reaches the cylinder, the mixture will be too lean to burn. You can remedy this by providing some means of making the mixture much richer when you're starting the bike. This is what the choke lever controls. You can also see why it's bad to run the bike with the choke lever on, since you'll end up with an overly rich mixture. Also, if you put the choke on when you're starting the bike on a warm day then you'll get an overly rich mixture too, which will stop the bike starting. Taken to extremes, the fuel will start condensing in the cylinder and stop your spark plugs from doing their job.

A final carburettor problem is called carb icing. This is usually only a problem when it's quite cold outside and there is high humidity (lots of water vapour in the air). When any liquid evaporates and turns into vapour, it takes in heat from it's surroundings. That's why you feel colder if you get wet - the evaporating water is sucking all your heat away. The same thing happens in the carburettor when the volatile fuel turns into fuel vapour. This makes the surfaces of the carburettor colder - by as much as 20 degrees celcius. This isn't normally a problem, but if the carburettor is already cold then the cooling effect of the vapourizing fuel can make the carburretor body drop below freezing. If this happens on a humid day, then as we suck in air we will also be getting lots of water vapour. The water vapour can condense on the cold interior surfaces of the carb, and ultimately freeze. The ice can block the jets and stop the carb from working.

Exhaust pipes (4 strokes)

Bike builders tend not to put parts onto a bike unless they have a purpose. So what is the purpose of the exhaust pipe. Why is is it shaped like that, and what's inside it?

You could theoretically run an engine without an exhaust pipe. It would be incredibly noisy - the exhaust valve is opened pretty quickly after there's just been a big explosion inside the cylinder. There's probably still some burning gases, and the whole mixture is going to still be extremely hot and would burn your legs. So, you need some way of getting these hot gases away.

The exhaust pipe serves three purposes. It takes the noxious gases which come out of the engine and moves them a bit further from the rider. We've already seen how carbon dioxide, carbon monoxide and water are formed during the burning of hydrocarbons. Sulphur dioxide is formed when the sulphur in the fuel is burned. Additionally, we find oxides of nitrogen in the exhaust gases. Normally nitrogen is pretty unreactive (it makes up 80% of the air we breathe) but the extremely high temperatures generated by the spark plug can cause it to react with oxygen.

Secondly, the exhaust pipe cools down the gases. It does this by allowing them to expand. The exhaust pipe is quite narrow when it leaves the engine, and then it gets wider. Allowing a gas to expand makes it cooler. Remember how compressing the fuel/air mixture with the piston made it hotter? This is the opposite effect. Once the gases have passed through the expansion chamber they are much cooler. That's why your exhaust pipe dries out fastest near the engine when it's been raining.

Finally, the exhaust pipe reduces the noise of the engine. Every time the exhaust valve opens, there's a pressure wave (shockwave) travels along the exhaust pipe. If the exhaust pipe was just a straight tube, this wave would escape to the outside world and you'd have a noisy bike. To stop this, the exhaust pipe also acts as a silencer. It contains various plates with holes in them (baffles), which force the exhaust gases to take a convoluted route to the outside world. This tends to breaks up and cancel out much of the pressure waves, which results in a quieter bike. If you get a hole in your exhaust before the silencer then the exhaust gases will escape there and everything will get much noiser.

Power and Torque

The power of a bike is measured in horsepower (HP). One horsepower is the energy required to move 33,000 lbs by one foot in a minute, which is the strength of some perfect horse. It measure the rate of energy use - which is the same thing which 'watts' measure, eg. for lightbulbs. A human being can produce something like a quarter of a horse power. Bike engines produce anything from 10 to 200 horsepower.

In practise, you see bikes rated in brake horsepower (BHP). Brake horsepower is named after the machine which is used to measure horsepower, which is called the prony brake. The bhp rating is the maximum attainable hp for the engine. It doesn't account for losses of energy through the gearbox, chain, wheel bearings. Even if you have a 50bhp engine, you wont be getting your full 50hp of rotation power at your back wheel if you've got a rusty chain and corroded wheel bearings.

An engine clearly delivers a different amount of power at different speeds. When it's going slowly, it provides less energy each second than if it was going quickly. If you look at the power graph for your bike, you'll see what power it produces at different engine speeds (rpm).

Torque measures ability of accelerate. Again, your engine will produce different amounts of torque at different speeds. Typically, it has low torque at low revs, maximum torque at something like 60% of it's maximum speed, and then the torque drops off as it reaches maximum speed. The more torque you have, the faster you can accelerate. That's why bikes feel most responsive at something like 60% of peak revs - you're at the point of maximum torque.

Why are bikes less responsive when the engine is cold?

Motorcycle Basics

Motorcycles are motorized vehicles for transporting one or two riders. Generally, a motorcycle has only two wheels, but any vehicle with fewer than four wheels in contact with the ground can be classified as a motorcycle. Three-wheel variations of the motorcycle include the "hack" (motorcycle plus sidecar) and the "trike" (short for motortricycle).
The layout of the modern motorcycle was established by 1914 and has remained fundamentally unchanged ever since. The overall structure and function of a motorcycle is quite simple. It includes a gasoline engine, which converts the reciprocating motion of pistons into rotary motion, just like the engine in a car. A transmission system transmits this motion to the back wheel. As the back wheel turns, it propels the motorcycle forward. Steering is accomplished by turning the front wheel via the handlebars and by leaning the bike to one side or the other. Two hand levers enable the rider to operate the clutch and the front brake, while two foot pedals enable him to change gears and control the rear brake.

Motorcycle Engine

Motorcycle engines work the same way that car engines do. They consist of pistons, a cylinder block and a head, which contains the valve train. The pistons move up and down in the cylinder block, driven by explosions of a fuel-air mixture that has been ignited by a spark. Valves open and close to allow the fuel-air mixture to enter the combustion chamber. As the pistons move up and down, they turn a crankshaft, which transforms the energy from the pistons into rotary motion. The rotational force of the crankshaft is transmitted, via the transmission, to the rear wheel of the motorcycle.

Motorcycle engines are generally classified by one of three characteristics: the number of cylinders they possess, the capacity of their combustion chambers or the number of strokes in their power cycles.

Cylinders

Motorcycle engines can have between one and six cylinders. For years, the V-twin design was the engine of choice for motorcycle engineers in America, Europe and Japan. The V-twin gets its name from the fact that the two cylinders form a V shape, such as the classic Harley-Davidson V-twin shown below. Notice the 45-degree angle in the Harley-Davidson V-twin -- other manufacturers may vary this angle to reduce vibration.




The V-twin is just one way to accommodate two cylinders. When the cylinders are oriented so that the pistons oppose each other, the result is an opposed-twin design. Parallel-twin engines have their pistons placed side by side in an upright position.

Today, the most popular design is the four-cylinder, which runs more smoothly and at higher revolutions per minute (rpms) than a comparable twin. The four cylinders can be placed in a row, or they can be arranged in a V-shape configuration, with two cylinders on each side of the V

Capacity

The size of the combustion chamber in a motorcycle engine is directly related to its power output. The upper limit is about 1500 cubic centimeters (cc

Motorcycle Transmission


A motorcycle engine can create an enormous amount of power, which must be delivered to the wheels of the vehicle in a controllable way. The motorcycle transmission delivers power to the rear wheel through a series of structures that include the gearset, the clutch and the drive system

Gearset




A gearset is a set of gears that enable a rider to move from a complete stop to a cruising speed. Transmissions on motorcycles typically have four to six gears, although small bikes may have as few as two. The gears are engaged by shifting a lever, which moves shifting forks inside the transmission.




Clutch


The job of a clutch is to engage and disengage power from the engine crankshaft to the transmission. Without the clutch, the only way to stop the wheels from turning would be to turn off the engine -- an impractical solution in any kind of motorized vehicle. The clutch is a series of spring-loaded plates that, when pressed together, connect the transmission to the crankshaft. When a rider wants to shift gears, he uses the clutch to disconnect the transmission from the crankshaft. Once the new gear is selected, he uses the clutch to reestablish the connection.

Drive Systems

There are three basic ways to transmit engine power to the rear wheel of a motorcycle: chain, belt or shaft. Chain final-drive systems are by far the most common. In this system, a sprocket mounted to the output shaft (i.e., the shaft in the transmission) is connected to a sprocket attached to the rear wheel of the motorcycle by a metal chain. When the transmission turns the smaller front sprocket, power is transmitted along the chain to the larger rear sprocket, which then turns the rear wheel. This type of system must be lubricated and adjusted, and the chain stretches and the sprockets wear, requiring periodic replacements.
Belt drives are an alternative to chain drives. Early motorcycles often used leather belts, which could be tensioned to give traction using a spring-loaded pulley and hand lever. Leather belts often slipped, especially in wet weather, so they were abandoned for other materials and designs. By the 1980s, advances in materials made belt final-drive systems viable again. Today's belts are made of cogged rubber and operate much the same way as metal chains. Unlike metal chains, they don't require lubrication or cleaning solvents.

Shaft final-drives are sometimes used. This system transmits power to the rear wheel via a drive shaft. Shaft drives are popular because they are convenient and don't require as much maintenance as chain-based systems. However, shaft drives are heavier and sometimes cause unwanted motion, called shaft jacking, in the rear of the motorcycle.

The other components that make a motorcycle a motorcycle are part of the chassis.

Motorcycle Chassis


The motorcycle chassis consists of the frame, suspension, wheels and brakes. Each of these components is described briefly below.

Frame


Motorcycles have a frame made of steel, aluminum or an alloy. The frame consists mostly of hollow tubes and serves as a skeleton on which components like the gearbox and engine are mounted. The frame also keeps the wheels in line to maintain the handling of the motorcycle.




How does Motorcycle Engine Work

A while ago, I wondered "how does an engine *really* work". I wasn't just thinking of explosion in cylinders pushing pistons up and down. I was thinking of the little details. This file is a tidied up version of my random notes and questions.

If you want more detail, then grab a copy of the book Vehicle and Engine Technology from Amazon. It tells you how engines, carburettors, chassis, tyres etc work. It's where I learned all this stuff from, and it's probably the only book on the subject I'll ever need.
How does an engine work

We want the engine to turn the back wheel. Or, more practically, to turn the gearbox since we want the bike to move both a very slow speeds and very fast speeds. The range of engine speeds available is roughly 1000 to 10,000 rpm which is a factor of ten. We want to ride a motorbike at anything from 1 to 100mph which is a factor of 100. So, we need a gearbox to provide a suitable range of gears. The engine drives the gearbox which drives the wheel. How do we get rotational motion from the engine?

We do this by a piston which provides periodic linear motion, connected by a con-rod to a crankshaft which turns the linear motion into rotation. The piston experiences a downward force on the ignition stage, which increases its monentum. The crankshaft acts as a flywheel which moves the piston through the other three stages (exhaust, intake and compression).

What affects the force on the piston when we ignite the fuel/air mixture?

* Combustion is not instantaneous. A flame spreads from the spark plug across the cylinder. This takes a significant amount of time. Remember that an engine running at 10,000 rpm completes one revolution in 0.006 secs.
* Combustion isn't always complete. The fuel/air mixture might now have completely burned by the time it gets punted out of the exhaust port.
* The amount of fuel/air mixture ignited. We can get more energy in each explosion by having more fuel and oxygen molecules in the cylinder to react together. This is why turbos and supercharges make an engine more powerful - they squeeze more fuel and air molecules into the cylinder. Nitros add an oxygen-rich chemical into the cylinder, which means we can burn more fuel.
* The fuel/air ratio. Different proportions of fuel and air will affect combustion. Let's look more at petrol first ...

Introduction

A while ago, I wondered "how does an engine *really* work". I wasn't just thinking of explosion in cylinders pushing pistons up and down. I was thinking of the little details. This file is a tidied up version of my random notes and questions.

If you want more detail, then grab a copy of the book Vehicle and Engine Technology from Amazon. It tells you how engines, carburettors, chassis, tyres etc work. It's where I learned all this stuff from, and it's probably the only book on the subject I'll ever need.
How does an engine work

We want the engine to turn the back wheel. Or, more practically, to turn the gearbox since we want the bike to move both a very slow speeds and very fast speeds. The range of engine speeds available is roughly 1000 to 10,000 rpm which is a factor of ten. We want to ride a motorbike at anything from 1 to 100mph which is a factor of 100. So, we need a gearbox to provide a suitable range of gears. The engine drives the gearbox which drives the wheel. How do we get rotational motion from the engine?

We do this by a piston which provides periodic linear motion, connected by a con-rod to a crankshaft which turns the linear motion into rotation. The piston experiences a downward force on the ignition stage, which increases its monentum. The crankshaft acts as a flywheel which moves the piston through the other three stages (exhaust, intake and compression).

What affects the force on the piston when we ignite the fuel/air mixture?

* Combustion is not instantaneous. A flame spreads from the spark plug across the cylinder. This takes a significant amount of time. Remember that an engine running at 10,000 rpm completes one revolution in 0.006 secs.
* Combustion isn't always complete. The fuel/air mixture might now have completely burned by the time it gets punted out of the exhaust port.
* The amount of fuel/air mixture ignited. We can get more energy in each explosion by having more fuel and oxygen molecules in the cylinder to react together. This is why turbos and supercharges make an engine more powerful - they squeeze more fuel and air molecules into the cylinder. Nitros add an oxygen-rich chemical into the cylinder, which means we can burn more fuel.
* The fuel/air ratio. Different proportions of fuel and air will affect combustion. Let's look more at petrol first ...

Suspension

The frame also serves as a support for the suspension system, a collection of springs and shock absorbers that helps keep the wheels in contact with the road and cushions the rider from bumps and jolts. A swingarm design is the most common solution for the rear suspension. On one end, the swingarm holds the axle of the rear wheel. On the other end, it attaches to the frame via the swingarm pivot bolt. A shock absorber extends upward from the swingarm pivot bolt and attaches to the top of the frame, just beneath the seat. The front wheel and axle are mounted on a telescoping fork with internal shock absorbers and internal or external springs.

Wh­eels

­Motorcycle wheels are generally aluminum or steel rims with spokes, although some models introduced since the 1970s offer cast wheels. Cast wheels allow the bikes to use tubeless tires, which, unlike traditional pneumatic tires, don't have an inner tube to hold the compressed air. Instead, the air is held between the rim and the tire, relying on a seal that forms between rim and tire to maintain the internal air pressure.

Tubeless tires are less likely to blow out than a tube-type tire, but on rough roads, they can be a problem because even a small bend in the rim can cause a deflation. Tires come in a variety of designs to match the needs of terrain and driving conditions. Dirt bike tires, for example, have deep, knobby treads for maximum grip on dirt or gravel. Touring bike tires, made of harder rubber, usually provide less grip but last longer. The tires of sportbikes and racers (generally steel-belted radials) deliver astonishing gripping power, especially considering the small area that is in contact with the road surface.

Brakes

The front and rear wheels on a motorcycle each have a brake. The rider activates the front brake with a hand lever on the right grip, the rear brake with the right foot pedal. Drum brakes were common until the 1970s, but most motorcycles today rely on the superior performance of disc brakes. Disc brakes consist of a steel braking disc, which is connected to the wheel and sandwiched between brake pads. When the rider operates one of the brakes, hydraulic pressure, acting through the brake line, causes the brake pads to squeeze against the disc on both sides. Friction causes the disc and the attached wheel to slow down or stop. Brake pads must be replaced periodically because the pad surfaces wear away after repeated use.

Driving a Motorcycle

Driving a motorcycle is very different from driving a car. Since motorcycles are two-wheeled vehicles, they topple over when ­they stop moving. A moving motorcycle is affected by gyroscopic forces that are unique to two-wheeled machines. As a result, new motorcyclists must develop the skills necessary to handle their machines and must be licensed before they can drive their motorcycles on the street. In particular, motorcycle riders must master the art of steering, braking and changing gears.

Steering

Steering a motorcycle at low speeds is a straightforward process. The rider simply turns the handlebar in the direction he wishes to go. This only works at speeds below five miles an hour. If a motorcycle is traveling any faster, the rider must use a different kind of steering, known as counter-steering. This type of steering may seem counterintuitive. That's because motorcycle riders must push the handlebars to the left to make the vehicle turn right and vice versa.

Here's how it would work out on the street. Imagine that you're riding a motorcycle on the interstate. In front of you, blocking the right half of your lane, is a wreck or some other obstacle. If you're a novice rider, you might be tempted to push on the right side of the handlebar, thinking this will turn the bike to left. In reality, this will steer the bike to the right, directly into the obstacle. Instead, you should push on the left side of the handlebar, which directs the front wheel to the right but steers the vehicle to the left.

Why does a motorcycle work this way? The motorcycle's wheels act like gyroscopes and create gyroscopic forces when moving at speeds above five miles an hour. One of the most interesting effects related to a gyroscope is a phenomenon known as precession. When a force is applied perpendicular to a gyroscope's axis of rotation, the resulting motion is perpendicular to the input force. This motion is called precession, and it's what causes the steering in motorcycles to be counterintuitive. It's also why instructors often arm their beginning riders with a simple mnemonic: "Push left, turn left. Push right, turn right."

Braking

Stopping a moving motorcycle requires that the rider use two brakes -- one on the front wheel, controlled by the right hand, and one on the rear wheel, controlled by the right foot. Both brakes should be used at the same time, although the front brakes are more powerful and will typically provide 70 to 90 percent of the total braking force. New riders often fear using the front brake, but it should be applied every time a motorcycle is slowed or stopped. Many accidents are caused by riders braking incorrectly. According to the California Highway patrol, locking up the rear brakes is a factor in the majority of motorcycle crashes.

Changing Gears

Early motorcycle clutches were operated by a foot pedal in the same way that automobile drivers use clutches. This was awkward and dangerous because it required that the rider's left foot be off the ground when the bike came to complete stop (at an intersection, for instance). British designers solved this problem with a hand-operated clutch. Today, hand-operated clutches and foot-operated shifters are standard on all models.

Motorcycle Types

­Motorcycles come in many different styles, each offering design and performance characteristics to accommodate specific riding conditions. Let's take a look at the common categories of motorcycles.

Street Bikes
Street motorcycles come with all of the necessary equipment to be street-ready. They have lights, mirrors, a horn and a muffler. Their tires have a tread pattern that provides good traction on both wet and dry roads. Street motorcycles generally come in two forms -- touring motorcycles and cruisers. Touring motorcycles are specially designed for long-distance travel. Their most distinctive features are fairings, aerodynamic wind guards that wrap around the headlight to enhance styling and reduce drag. Touring bikes also come with other long-distance amenities, such as saddlebags and a comfortable passenger seat. Cruisers, which typically have no fairings, offer a more laid-back look. They are built with swept-back handlebars, low seats, and casual riding positions with forward-set footpegs.


Sportbikes
Sportbikes are designed to handle well at high speeds and on winding roads. They offer multi-cylinder engines to produce more power, aluminum alloy frames, stiff suspensions to improve handling, high-grip tires and powerful brakes. Instead of sitting up straight, sportbike riders lean forward over the gas tank to reduce wind resistance.

"Naked Bikes"
Naked bikes offer the performance of sportbikes without the aesthetics. In most cases, they are stripped of any unnecessary bodywork. Because they're often the product of bike customizers who want a "road warrior" appearance, naked bikes are also called streetfighters, especially in Europe.

Traditionals
Also known as standards, traditionals look and handle like an archetypical model known as the Universal Japanese Motorcycle (UJM), built primarily in the 1970s. The UJM was an all-purpose, do-everything bike, and today's standards offer the same versatility and straightforward design.

Off-road Bikes
Off-road motorcycles include both motocross bikes and dirt bikes -- machines designed to handle jumps, bumps and other obstacles found on closed racing courses or woodland trails. Off-road motorcycles have narrower, lighter frames, increased ground clearance and advanced suspension systems. They also have a kick-starter to reduce weight and tires with a knobby tread pattern for increased traction. Because off-road bikes usually don't come standard with lights, mirrors, a horn or a muffler, they aren't street-legal

Dual-purpose
Dual-purpose bikes, also known as dual-sports, are street-legal motorcycles that offer some off-road capabilities. Like dirt bikes, dual-purpose machines are lightweight and durable. Like standards, they offer great versatility for newcomers and long-time riders alike. The dual-purpose motorcycle falls somewhere in between a dirt bike and a street motorcycle. For example, dual-purpose bikes feature specialized tires that work on both dirt and pavement.

Saturday, July 11, 2009

Beam Breakers





If there's one thing Germans know besides beer, it's automobiles. Which, amongst other promising signs, bodes well for the Deutsch team behind Beam Breakers. Developed by Simulis Software for publishing newcomer Fishtank Interactive, this pedal-to-the-metal futuristic rendition of mile-high chases and races aims to bring console-style gaming onto Pentium-compatible platforms in Q1 2002. And despite the fact that sales of PC driving games have dwindled following the wake of disappointing sales figures for BreakNeck, DethKarz, and Ford Racing, chances are good that Beam Breakers will deliver solid arcade thrills...besides, its competition at stores will be almost nonexistent.
Unlike most driving games, in which fine-tuning plays a large role, setup here is minimal. Faced with conceptual parodies of current showroom models, you merely choose from the vehicles that are unlocked and proceed right into the gameplay. Selections include the Dudge V12, Lincoln M3, Acora, CMG Oldsmobile, and other recognizable spoofs. Each car not only looks unique, touting wings, fins, spoilers, or stranger accoutrements, but handles differently as well. Inherent arcade physics notwithstanding, the program accounts for size and weight differences, though it doesn't relay such information to you during pregame preparation in any quantifiable form besides visual. Any choices made at this point will surely be based on top-speed attributes and the aesthetic viability of the roadsters you've recently unlocked by completing one of Beam Breakers' 30-plus missions.


According to the plot, you're a taxicab driver working a postmodern New York and looking for a big break. Plot details are scarce at this point, but it is certain that the story will evolve throughout play, as scenarios see cabbies interact with Russian, Italian, and Japanese gangs. Hence, level goals will include stealing vehicles and getting them to a safe haven or avoiding police long enough to safely drop off gangsters at a predetermined destination, amongst edgier fare. Few mission choices are available at first, as many more become unlocked once initial entries are successfully completed. All told, the progression scheme is logical, if uninventive, teaching beginners the basics at first and eventually ramping up difficulty settings until you're ready for a real challenge. Of course, "freeflight" options are offered as well--these let you get to know the lay of the land, but the best way to learn anything is naturally by doing.

Beyond basic configuration details lurks a simple, yet simultaneously complex racer. Environments are universally sprawling, multilevel urban backdrops teeming with traffic. Picture the air-taxi sequence spotted in The Fifth Element and you'll have an idea of what's in store. Literally hundreds of buses, trucks, cars, and transports fly around the city streets, going about their daily business. It lends locales motion and depth but makes for hazardous navigation. Dodging floating billboards, light emplacements, and hovering ads at top speed can be frustrating; you don't even want to imagine what doing so is like while hordes of commuters whiz by. Readily apparent is the need to create your own path throughout each stage, at the same time being bound by set checkpoint constraints. It doesn't matter how drivers get to these glowing green markers in the interim, just so long as they pass through them, period.

Ducati World Racing


Last year, Acclaim released F355 Challenge for the Sega Dreamcast. It was a superb racing game that featured one of the most respected vehicle manufacturers in automotive racing: Ferrari. With the release of Ducati World Racing Challenge, Acclaim was undoubtedly hoping to capture that same essence using yet another revered name in Italian racing. Unfortunately, while the game boasts about 40 different Ducati motorcycles that span the length of the company's storied existence since World War II, Ducati World Racing Challenge is severely hampered by its poor control, obsolete graphics, and bad sound.
Ducati World Racing Challenge is split up into two distinct gameplay modes--quick race and Ducati life--the latter of which makes up the majority of the game. Similar to the Gran Turismo games for the PlayStation and the evolution mode in EA's Need for Speed: Porsche Unleashed, this open-ended mode lets you choose from a number of racing events throughout the history of Ducati's 50-year product line. You start Ducati life with $10,000 with which to buy a bike, helmet, and leathers. You'll only be able to afford a cheap bike initially, but you can gain more money by competing in the many racing events available. Most of these events have some sort of prerequisite that you need to meet before being allowed to compete--such as possessing a certain class of license or bike--and by successfully completing the events, you'll be rewarded with new bikes, hidden tracks, and prize money. You can use prize money to stock your garage full of Ducatis that range from classics from the '50s and '60s to modern-day beasts like the 996SPS and 748. The game lets you squeeze more performance from your bike by letting you upgrade various parts like the gearbox, exhaust, brakes, wheels, tires, and clutch.

The quick-race mode is similar to Ducati life, but access to some of the more exotic Ducatis and racetracks isn't as restricted, as there isn't any kind of resource model to keep the high-end bikes out of your reach. But as in Ducati life, the various races in this mode include vintage class, modern class, and special events, and you can compete against the clock in addition to the computer-controlled opponents.

However, despite the breadth of racing options available in the game, Ducati World Racing Challenge suffers from serious problems. The first of these that you'll notice is the game's outdated graphics. The tracks are all very sparse--course objects like bridges and grandstands are lacking in detail, and 2D sprites are used liberally to represent peripheral objects like trees. The bike and rider models are also disappointing. The textures are washed out and fuzzy, and the bikes themselves are so rough-hewn that they practically look like they've been mangled in an accident. The game lets you play from three different camera views--one third-person view and two first-person angles--but the first-person views really limit your peripheral vision, making it impossible to see any bikers who aren't directly in front of you.

The game's sound is unacceptable. While the fast-paced tune that plays through the various menus in Ducati World Racing Challenge is rather catchy, the bikes' sound effects are poor. Ducatis are known for their signature growling engines and throaty exhaust notes, but some of the bikes in the game sound like blast furnaces instead. The effects of driving over different surfaces and of crashing are generic, and the incessant squealing of the tires becomes annoying almost immediately.
Yet the most glaring problem in the game is the control. The game has a number of driving tests--designed to familiarize you with maneuvering your bike, finding the best racing line, cornering, and so on--that you must pass within a set time limit, but you'll hardly put these skills to use while racing on the tracks. In fact, with a little practice, you can lap certain courses over and over without ever braking. It's a shame that the physics in the game are so simplistic, because Ducati World Racing Challenge is one of the few PC bike games to actually feature separate inputs for front and rear brakes. However, the only difference between the two is that the front brakes are slightly more powerful than the rear brakes. There are no penalties for staying on the front brake too long while entering a turn, nor will you encounter problems applying the rear brake while coming out of a corner--both of which would send you onto the asphalt in real life. Additionally, all the tracks in the game are variations of five core designs, and all five designs are forgettable. There's also no online multiplayer mode available, though there is a horizontal split-screen option for two players on one computer.

The potential of Ducati World Racing Challenge is clearly evident, and it could have been the Porsche Unleashed of motorcycle games. But while it does have some appeal for die-hard Ducati fans, Ducati World Racing Challenge is ultimately hamstrung by its many problems. In the end, Ducati World Racing Challenge proves that it takes more than a recognizable license to make a high-quality racing game.

Castrol Honda Superbike Racing


Electronic Arts has proven with the Moto Racer series that it knows what a good motorcycle racing game is. That's why it is so disappointing to see that Castrol Honda Superbike is so noticeably inferior. It isn't a horrible game, but other than offering a strong simulation aspect, there's not much there.

Castrol Honda Superbike, as the name implies, is a racing game that exclusively features real Honda RC45 racing bikes that you can race on 14 real tracks from around the world. The game has several different settings that let you customize your bike. Most notable are the different sprocket settings that let you change your bike's gear-ratio settings. Each gear can be adjusted so that you can tailor and maximize your motorcycle's performance for each track.

The control of the bikes is actually quite good, especially when using the Dual Shock controller - one stick steers the bike while the other adjusts your speed. The bike reacts as it would in real life, which means that when you're going around a tight turn you must take it at a reasonable speed so your bike doesn't go slamming into a wall. If this is a problem for you, the game does offer six different difficulty settings, some of which have options that help steer your bike for you while you turn, as well as reduce your bike's speed so that you can make the turn. The AI of the track's seven computer-controlled bikers isn't anything special. The bikers just race along the course in a standard staggered style so that at just about any point in the race you have someone to directly compete against. If you do decide to race this other player, the game features a two-player head-to-head split-screen mode.

Visually, the game isn't that impressive, especially when compared with Moto Racer 2, Electronic Arts' Motorcycle racer that was released last year. The riders look a little too polygonal, and their motions aren't all that realistic. Take for instance the animation of your rider falling off the bike when you crash into a wall or when he's laying the bike down on it's side when going too quickly into a turn. The rider comes off the bike as if the hand of God reached down and plucked him off the bike without letting him move a muscle. Most of the rider's basic animations look more than a little awkward as well. The tracks themselves look decent, and the game doesn't suffer from too much pop-up.

In the audio department, the game is nondescript, especially since there isn't any music during the races. The effects and engine sounds are fairly authentic but don't really keep you company during the races.

The only players this game would really appeal to are bike-racing fanatics, who are really into the sport. Players who aren't won't appreciate the extremely real-world bike physics that make you take corners at very low speeds. The rest of us, who just think motorcycle-racing games are fairly neat to play from time to time, should just stick with Moto Racer 2.

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Mountain Biking Action on the Playstation 2


There’s no denying it, our sport makes great source material for video games. Surprisingly, there hasn’t really been an abundance of solid mountain bike titles released to the home console market. Perhaps the most successful to date was the gravity oriented Downhill Domination by Incog for the Playstation 2, which hit the scene back in 2003. These days the PS2 clings to life while video game fans flock to current generation consoles such as Nintendo’s Wii and the Sony Playstation 3 but that doesn’t mean the old workhorse doesn’t have a place in our entertainment centers and hearts. Enter French developer Valcon whose American presence in the video game world is synonymous with slick titles for bargain basement prices. Realizing that mountain biking offers up all of the excitement, terrain challenges, and racing action that many other powersports-devoted games have capitalized on, they brought their PS2 title Mountain Bike Adrenaline stateside with an unbeatable $14.99 MSRP. The stir-crazy staff of MBT got our mitts on a copy of Mountain Bike Adrenaline and gave our thumbs a solid workout to determine whether Valcon has released a sleeper-hit or quiet bomb onto the market.
The Set Up
We’re going to assume you have a pretty solid grasp on the basics here. Like most outdoor sports games, Adrenaline centers on the idea of your virtual character taking on the mountain’s fury (which includes man built stunts, ladders, and skinnies) from the saddle of a licensed virtual mountain bike. The game breaks down into four categories:
Arcade: Free roaming environments in which collecting icons keeps you going.
Stopwatch: Racing against, you guessed it- a stopwatch.
Challenge: Like the name suggests, the game presents some wicked challenges to master ranging from Dexterity Challenges (balancing on ladders and skinnies to cross checkpoints) to Trick Challenges where the computer throws out a series of stunts that you have to bust before time expiries.
Freedom: This mode can only be unlocked by beating the challenges listed above but offers truly free environment exploration.

The game offers some sweet locations to romp on as well (Hawaiian Islands, Canada, USA, and France), which are broken down into real mountain ranges (with different terrain) such as the Rockies and the Alps.

Finally there are more than 80 bonuses to unlock as you progress from a helmet-less fool to a professional free rider. Best of all, the programmers have gone through the trouble of licensing real bike models from Lapierre, Kona, Cannondale, Qbikes and Specialized.

The Game Play
We have to admit, on paper, Mountain Bike Adrenaline sounds like a dream come true. Unfortunately some of the best ideas translate poorly onto the screen. The only way to be sure is to spend some time with the game in question; to play it until it glitches out or fries your brain until spring arrives. Adrenaline looks good, even on the now antiquated PS2 hardware. The frame rate is consistent and, unlike most games of the genre, the action is never dizzying or disorienting. Rather MBA takes a more methodic approach to the sport while integrating technical terrain, balance, and timing into the formula. Holding the X button gets you pedaling but drains your power meter so to succeed, the player must coast whenever the terrain allows it. Also unique here is a concentration bar that when activated slips the world into slow motion for a few moments. This is especially handy when negotiating tricky ladders and 2x4s that hover ominously across a 100-foot gorge. Rider animation is spot on and the bikes look pretty darn close to pixilated versions of their real-life counterparts. Crashes are pretty cool too, often looking pretty darn painful.
Unfortunately, this review isn’t all praise. The control is definitely a little awkward and takes some serious practice for even moderate results. Don’t get us wrong; the button control is laid out intuitively and can be mastered in seconds. Controlling the bike onscreen, however, can definitely be a lesson in frustration. Especially in the dexterity challenges, which are filled with wooden stunts and ladders, 90-degree turns, and cliffs below that require you to instantly start the level over should you topple. Expect at least a couple of hours of steady frustrating devotion before being able to successfully complete levels. We fear many will grow weary of the process before mastering the skills required and miss out on a fairly rewarding experience. In life patience is a virtue. In Mountain Bike Adrenaline it is a requisite.

In addition to the sloppy controls, the environments can lead to additional problems. The wooden obstacles always feel slippery, like the bike is riding on ice. This coupled with vague control results in many unwelcome wild rides. The mountainsides are loaded with foliage, rocks, and wooden fences, each of which can snare your bike and hold you annoyingly captive until you can wiggle your way out with the pre-jump button. A reverse control would have easily prevented a lot of stress here!

The Bottom Line
$15 really doesn’t get you much entertainment in the world of mountain biking. It doesn’t offer much more in the realm of video games either. That said, Mountain Bike Adrenaline is a worthy way to drop a few bucks, especially in the long cold winter months where every little fix helps. Just expect a rather steep learning curve before finding your rhythm- just like in real life.

Thursday, July 9, 2009

MotoGP'06 Bike Racing Game




climax knows a thing or two about speed, but the team has outdone itself this time by delivering a new game on a new console less than a year after the release of MotoGP 3. The short development cycle is definitely apparent in that MotoGP 06 is less a significant step forward for the series than an incremental upgrade to the previous game. However, given that the previous game is one of the best racing titles on the Xbox, that's certainly not a bad deal for racing fans. When it comes down to it, MotoGP 06 is not without its flaws, and the increased price is tough to swallow. But where the rubber meets the road, this is still a great game that will keep racing fans coming back for a very long time.
MotoGP 06 has two distinct race circuits, the Grand Prix circuit and the Extreme circuit. If you're looking for a sim racing experience, you can race on one of 17 real-world GP tracks against riders from the 2005 or the 2006 MotoGP season. You can race these tracks in quick race, time trial, or career mode. If you're playing single-player, there are four different difficulty modes to choose from, although if you're a series veteran, you'll need to skip the easiest two settings and go straight to "champion" if you want any sort of a challenge. Even then, the challenge in racing the Grand Prix tracks comes from the tight layouts that demand a lot of technical skill when choosing your lines to maintain as much speed as possible throughout the many difficult hairpins and chicanes you'll encounter.
f the Grand Prix circuit is a bit too technical for your taste, you can try out any of the three divisions of the Extreme circuit. There are 17 fictional extreme courses in the game, and you can race them on 600cc, 1000cc, or 1200cc bikes. As the bike size increases, the tracks become more difficult because the larger bikes are much faster, heavier, and more difficult to control. In comparison to the GP tracks, the extreme tracks require much less technical skill and instead reward a heavy hand on the accelerator. These tracks are so fast that you rarely have to use the brakes at all, and it can be a blast to open up the throttle in the long straights and wide, sweeping turns.

Between the two circuits and 34 tracks (plus reverse versions of each track), there's plenty of variety to be found in MotoGP 06. It's refreshing to be able to go from a tense, white-knuckled GP race that will have you on the edge of your seat trying to whittle down your lap times one-tenth of a second at a time, to a blazing fast, arcade-style race around an extreme track that will have you grinning from ear to ear with the sheer speed of it all.

The bikes in the game all handle just as well as they have in previous Moto GP games, which is to say that they all feel properly weighted and powerful, and they're all a lot of fun to ride. The default control scheme works very well, with rear and front brakes assigned to the left and right triggers, respectively. The independent braking system is an important component of the control because proper use of the rear brake will let you powerslide around corners to keep your speed up, while controlled use of the front brake is critical in the tighter turns that require a bit more precision.
The artificial intelligence in MotoGP 06 is certainly functional. While the computer-controlled riders mosey along at a leisurely pace on the easier difficulty settings, they provide plenty of stiff challenge at the higher difficulty settings. Of course, the AI riders very rarely crash, and they tend to keep the same line throughout each race, but you don't get the rubber-band effect that causes opponents to unrealistically bunch up in some other racing games. You'll still want to play it clean, though, as the other riders will almost always win when push comes to shove. Even though the AI is a very rigid substitute for real, live players, it's certainly a functional alternative if you don't want to play online.

Each of the pro racers in the game has his own bike, with all of the appropriate logos and stats. There are 19 riders and bikes for the Grand Prix circuit, although many of the bikes are actually the same model but with different skins. The Grand Prix bikes are all based on their real-world counterparts from manufacturers like Yamaha, Kawasaki, and Ducati. The extreme motorcycles, on the other hand, are highly customized street bikes that are equally fun to ride. The extreme bikes are lighter and more nimble than the Grand Prix bikes, and they also feature much more radical styling. All bikes can be customized by adjusting parameters like gear ratios, tire compound, and suspension hardness. The extreme bikes can be upgraded with new parts, so you can tune your engine, reduce the weight, purchase better brakes, and even install nitrous oxide.
The crux of the single-player game in MotoGP 06 is the career mode. You can choose a circuit and difficulty and then progress through a series of 17 races, accumulating points depending on where you finish in each race. At the end of the season, the rider with the most points accumulated is the champion. Before each round, you're given a variety of options. You can practice racing the track as much as you want, memorizing the best line to take for each and every turn to ensure your victory on race day. Once you're prepared, you can move on to qualification, where you have 10 minutes to post your best lap time. Depending on how your time compares to the other riders, you'll be assigned a position on the starting grid for the actual race. After qualifying, you're ready to race against 15 riders if you're on the extreme circuit, or 19 on the Grand Prix circuit.