Welcome to Netrider ... Connecting Riders!

Interested in talking motorbikes with a terrific community of riders?
Signup (it's quick and free) to join the discussions and access the full suite of tools and information that Netrider has to offer.

Motoczysz C1 - New American MotoGP bike

Discussion in 'Bike Reviews, Questions and Suggestions' at netrider.net.au started by NovaCoder, Apr 13, 2005.

  1. This thing incorporates some very interesting design ideas, some of which will probably make it to the road one day.

    Motoczysz C1 (Flash site)

    Some 'light' background material:

    This is part 3 in a multipart series on the Motoczysz C1, an american built motorcyle scheduled to compete in MotoGP. This entry discusses the first technical aspect of the the Motoczysz C1 which makes it different...the front forks. First, a bit about current fork design. Current superbike forks perform two duties: 1) They provide support for the motorcycle over the front tire. 2) They provide the front suspension. We'll take a look at each of these.

    As a support for the front tire, the forks are submitted to a fair amount of stress; mainly when the motorcycle is braking, but also when it is cornering. When the motorcycle is braking there is a great deal of stress placed on the front forks. Just about all of the weight of the motorcycle (roughly around 350 pounds for a MotoGP bike) and the rider (roughly about 160 pounds for a MotoGP rider) are shoved onto the front forks while it is braking. Keep in mind that motorcycle racers try to brake as late as they can (to keep as mutch speed as they can in the straights) and therefore brake as hard as they can. This means that the front fork is subjected to a lot of pressure.

    Just about all motorcycle forks are round. The round shape provides a good structure for handling all of this stress. However, this is contradictory to what would make a good cornering fork. While cornering, a rider wants the front end to move left and right to absorb some of the bumps and to provide a good "feel" for the front end. Round motorcycle forks work best if the bike is standing straight up because, except for the flex in the forks, the suspension components only move up and down. The further the bike leans over, the less the forks move up and down and the more the bumps in the road move the tire left and right. So the farther the bike is leaned over, the less the front suspension works. A rigid structure, like a round fork, provides a lot of rigidity for braking, but it also provides a lot of rigidity for cornering...which means less suspension while leaned over and less "feel".

    The Motoczysz C1 deals with this by making the forks oval, with the long part of the oval pointing to the front and back of the bike. This is a better design because is solves both problems described above. 1) A rigid structure, the oval with the long areas pointing in parallel with the bike, is provided for rigidity during braking. 2) A flexible structure, the short area of the oval, is provided for cornering. When the bike is leaned over far, the oval flexes left to right. This provides some suspension while the bike is leaned over far and it also gives the rider a good feel for how the front tire is moving over the pavement. So the rider gets a more rigid fork while braking and also gets better suspension and feel while cornering.

    Now, on to the suspension part. Inside conventional forks is the suspension. You'll find fork springs, fork oil, gaskets, shafts, and holes. I won't go into how forks work, but suffice it to say that you typically have telescopic forks in which one part of the fork is smaller in circumference and moves up and down inside the larger circumference part of the fork, like a telescope. The biggest problem with this is that the fork binds. Binding occurs when the fork bends, which the fork will do under stress, and the movement of the forks is restricted due to the bending. So the more stress you have on the forks (e.g. the harder your braking and therefore the more the forks bend), the worse they work.

    The Motoczysz C1 deals with this by removing the suspension components from inside the forks to a single shock outside the forks. Instead of having the fork springs, fork oil, gaskets, shafts, and holes inside the forks, there is a single shock between the bike and the forks. Now, the forks only contain bearings so they can move up and down freely. Any bending occuring in the forks will not affect the shock and how well the suspension works. In short, binding doesn't occur. Moreover, there should be a weight decrease as there is no need for two sets of fork springs, gaskets, shafts, and twice the amount of fork oil.

    Another advantage of the Motoczysz C1 front forks is the ability to change the rake and trail of the bike. This lets racers change the handling characteristics of the bike far quicker and easier then conventional methods, making it easier to test different configurations for different racers and tracks.
  2. nice bike........