Re: NC29 Race engine project
Posted: Fri Jun 19, 2009 10:15 am
Well, I picked up the VFR gearbox this afternoon and disassembled both the VFR and CBR gears and lined everything up.
As Dan mentioned in the other thread the VFR and CBR input shafts aren't interchangeable. Bugger. Here is proof.

VFR shaft on top, CBR on bottom
So i've gone with the standard CBR 1st gear (no choice) and put in the VFR 2nd and 3rd. Lets face it, you don't use first gear when racing very often.
Here are the two gearboxes dismantled and side by side. Cbr on the left, VFR on the right. Notice the VFR doesn't have a 5th gear pinion on the output shaft. Hence why it was sold to me!

Here is a list of the pinions I used from which bike written in the order left to right as seen in the crank case;
INPUT SHAFT
2nd VFR, 6th CBR, 3/4th (integral) VFR, 5th CBR, 1st (integral with shaft) CBR
OUTPUT SHAFT
2nd VFR, 6th VFR, 3rd VFR, 4th VFR, 5th CBR, 1st CBR.
The reason there is more of a mix and match than you might expect is because the shape of the gears dogs that interlock on the output shaft are slightly different from VFR to CBR, and I have tried to keep the interlocking gears from the same machine to avoid any damage.
As Dan mentioned in the other thread the VFR and CBR input shafts aren't interchangeable. Bugger. Here is proof.

VFR shaft on top, CBR on bottom
So i've gone with the standard CBR 1st gear (no choice) and put in the VFR 2nd and 3rd. Lets face it, you don't use first gear when racing very often.
Here are the two gearboxes dismantled and side by side. Cbr on the left, VFR on the right. Notice the VFR doesn't have a 5th gear pinion on the output shaft. Hence why it was sold to me!

Here is a list of the pinions I used from which bike written in the order left to right as seen in the crank case;
INPUT SHAFT
2nd VFR, 6th CBR, 3/4th (integral) VFR, 5th CBR, 1st (integral with shaft) CBR
OUTPUT SHAFT
2nd VFR, 6th VFR, 3rd VFR, 4th VFR, 5th CBR, 1st CBR.
The reason there is more of a mix and match than you might expect is because the shape of the gears dogs that interlock on the output shaft are slightly different from VFR to CBR, and I have tried to keep the interlocking gears from the same machine to avoid any damage.