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Old October 18th, 2017, 04:55 AM   #21
tgold
ninjette.org sage
 
Name: Timm
Location: West Seneca, NY
Join Date: Oct 2015

Motorcycle(s): 2006 1050 Speed Triple, 2010 250 Ninja racebike, YZF320RR? Racebike

Posts: 556
MOTM - Nov '15
Quote:
Originally Posted by Kiwi rider View Post
I was running an aluminium rear sprocket on my CBR300 which weighed exactly 1/3rd of the weight of steel OEM one. I also swapped out my sprocket bolts for aluminium ones and aluminium nuts with a steel helical insert for the thread. Set to about 30Nm with a drop of loctite on each thread. Never came loose.
Good to reduce your reciprocating mass and unsprung weight as much as possible.
I think the Bridgestone evo S21's are one of the lightest tyres too.
Aluminum fatigues and stretches more easily than steel, so it requires more attention as far as the correct torque goes. I think with five six bolts you're probably safe though. If there are only four bolts on the CBR carrier then I'd probably not risk it myself. I've been looking at the cushions drive/sprocket carrier assembly and I think it is way overbuilt so I'm looking at taking some weight out of it. I'm probably going to reduce the number of bolts holding the sprocket from six to three but I'll keep them steel or titanium, reduce the weight of the casting and machine the bearing sleeve from aluminum instead of steel.

I'll also be machining a significant amount of weight out of the rear brake rotor. About the only time I use the rear brake is when I run off in the grass.
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