GSXR output shaft backlash

[Ben Beacock]

being unfamiliar with bike engines/trannies, what is normal for the backlash(play) on the output sprocket when its in gear? we seem to be getting somewhere around 15-25 degrees.

Ben

Ben Beacock
Chassis Design and Technical Coordinator
Gryphon Racing - University of Guelph

[Spike]

I'm not sure the exact amount but they do have some play. I wouldn't be too worried about it.

[ben]

Would I be correct in suggesting that the backlash is simply the gap between the dogs?

Ben

[woollymoof]

plus any gaps in the gears

[Ben Beacock]

that sounds about right.. i forgot about the dogs in the tranny. I'm trying to trace down a 'shuddering' we get when braking hard in gear

Ben Beacock
Chassis Design and Technical Coordinator
Gryphon Racing - University of Guelph

[Denny Trimble]

That shuddering is caused by a lack of extreme front brake bias in an FSAE car. In other words, you're probably not going to eliminate it unless you do two rear brakes.

Unless someone out there has found a way?

University of Washington Formula SAE ('98, '99, '03)

[Ben Beacock]

That, of course, is the other problem, and I picked up a proportioning valve this morning to hopefully solve that. Our problem is that the rear brake works at a 3.6:1 ratio through the diff so its almost all rear braking right now (its like a handbrake). Great for donuts and such, but not very useful on the track. http://fsae.com/groupee_common/emoticons/icon_smile.gif

Ben Beacock
Chassis Design and Technical Coordinator
Gryphon Racing - University of Guelph

[Scott Harsila]

The shuttering could also be cause by not matching engine RPMs to tranny RPMs on downshifts with a throttle blip.
Clutch in-shift-blip-clutch out

University of Washington
Formula SAE 2001-2003

[terc04]

We too have had a shuddering problem on our cars epuiped with single inboard rotors fitted to the differential. The source seems to be hysterisis in the differential(Zexel). The problem shows up when braking hard over rough parts of the track or when a downshift is not performed properly. The only real cure is to mount dual rear brakes somewhere on the output shafts or use a tighter differential.
This problem has recently menaced our team to the point of major overhauls to some of our old cars. Unfortunately it is too late to redo the new car, but it never seems to be a problem for us during competition.

Tim
University of Missouri - Columbia