What kills a motorcycle?

Discussion in 'Motorcycles & Boats' started by Ershank, Aug 28, 2004.

  1. Ershank

    Ershank Formula Junior

    Aug 26, 2004
    Full Name:
    Jason Z
    The GTR is nice, and seems to be able to travel with superbike acceleration...
    Anyone have any insight on the 0-100-0 times for any new production literbike (inline 4...)?

    ****"In Autocar's 0-100mph-0 test they rode a Suzuki GSXR-1000 to a 10.89sec time. The braking is what killed the time, here's the break down:

    0-30mph: 1.12s
    0-60mph: 2.64s (!)
    0-100mph 5.03s
    reaction time: 0.23s
    100mph-0 5.63s

    Most of the cars were stopping in under 4.5s, and the best cars were closer to with more tire or maybe an air brake it could definitely break the 10s barrier. Basically the only reason the cars are still in touch with the bikes is because of braking."****

    I think that the bikes major flaw, isnt that it has 2 wheels, but that the center of gravity is so high in relation to the wheelbase. How about a longer wheelbase on the bike? Be snot on the twisties but it would effectively lower the angle of the center of gravity in relation to the rubber, and allow both wheels to stay planted during hard acceleration/braking.

    Therein lies our next problem. Turning with a longer wheelbase. I remember the GMC Denali and even some 87-90 Honda Preludes having rear wheel steering as an option. Would it ever be possible to introduce a long 2 wheel steered bike? Rear steering on cars has been shown to shorten the turning radius by as much as 25%.

    There are already turbocharged hayabusa's. One individual has a 550WHP 'busa, but what does all this power mean if you can only accelerate and deccelerate as fast as the helium filled wheels let you?

    Lengthen the wheelbase and provide dual-steering. It would make for a VERY unique project. I just wonder how much brass it would take to ride one of these monsters on the track.

    I only wish I could make the $10 grand to afford one of these machines. (17)
  2. UroTrash

    UroTrash Three Time F1 World Champ
    Consultant Owner

    Jan 20, 2004
    Full Name:
    Internet Poseur
    Sport bikes do indead have a relatively high center of gravity, you need that to flick through chicanes.

    According to Motorcycle Consumer News (no ads, VERY unbiased), the shortest stopping was a Valkerie (article a few years old) because its so long and heavy, there was no tendency to stoppie.

    The greatest literbikes will have a compromised stopping distance in trade off to best handling since they will stoppie pretty easily.

    Dan Gurney may have really started to figure it out with his "Alligator", about the ugliest bike I have ever seen.
  3. sjb509

    sjb509 Guest

    There have been two-wheeled steering showbikes from Yamaha about 10 years ago. The advantages are just as you stated, that the same handling could be accomplished with a longer wheelbase.

    A system like this would be heavy and sap rear-wheel horsepower however. It would difficult if not impossible to achieve the drivetrain efficiency and weight of a roller chain. That the technology has been around for a long time and not seriously tested on a track leads me to believe that for a superbike at least the compromises are too great. However, for a cruiser or touring bike it could be used without as much consideration to the weight and efficiency penalties.

    For a superbike perhaps a better system would be active suspension which squats the bike down during acceleration, then provides softer long travel suspension while leaned over to absorb mid-corner bumps. Unfortunately an active suspension system like this would probably be banned for safety reasons by a sanctioning body.
  4. Ershank

    Ershank Formula Junior

    Aug 26, 2004
    Full Name:
    Jason Z
    Yeha it would sap the RWHP alright, but if the bike had lets say... a 550hp turbo 'Busa engine in it, would it really make that much difference?

    Lets be unrealisticly generous and say from 550 we only have 400 rwhp at the rear now, and the weight of the bike went from 550-700 pounds.

    Even with a driver (how about 200 lb?) and fuel, the power to weight ratio would be 2.25 lb/hp.... and you could use it! Or would the torque be too small coming from the small displacement engine?
  5. ssmith2k3

    ssmith2k3 Karting

    Apr 7, 2004
    Some Random Stuff:

    I've seen a Yamaha off-road bike with all wheel drive - it has basically some kind of hydraulic converter that drives the front wheels as well, and it seems to vastly improve grip when in turns. Also, AFAIK, for the turbo busa you speak of (at least the ghostrider one that does wheelies at 200mph), I believe the turbo boost does not kick in 'till about 7k rpm which makes it a pretty hairy machine. I've heard that the best configuration for defeating turbo lag in motorcycle applications is the triple (3 cylinder) engine-there is some companies that are trying out Triumph turbo'd bikes.

  6. Ershank

    Ershank Formula Junior

    Aug 26, 2004
    Full Name:
    Jason Z
    #6 Ershank, Aug 29, 2004
    Last edited by a moderator: Sep 7, 2017
    Could you even imagine a 3 cylinder, all wheel drive, dual steering, turbocharged bike?

    It would truly be unique to say the least. It's really a shame that modern sportbikes are all alike. The manufacturers have hardly any artistic merit.

    And I bet it would look something like a bike I've seen in a cartoon once...
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