PDA

View Full Version : Wanted Right Crank Arm

DownHillDan
February 10th, 2009, 11:33 AM
I need a "right crank arm" for my 2000 trek XO1 cross bike, the crank set is a Shimano RX100, 39/50 teeth
DownHillDan
April 21st, 2009, 01:47 PM
bump:D:D:D:D
BottomBraket
April 21st, 2009, 02:52 PM
I need a "right crank arm" for my 2000 trek XO1 cross bike, the crank set is a Shimano RX100, 39/50 teeth

We need to know number of arms, Bolt Circle Diameter (BCD), Length, interface (square taper, ISIS, etc).
DownHillDan
April 27th, 2009, 03:23 PM
We need to know number of arms, Bolt Circle Diameter (BCD), Length, interface (square taper, ISIS, etc).

How do I find this stuff out?
wrench177
April 27th, 2009, 04:06 PM
For the number of arms just count them.

BCD (http://en.wikipedia.org/wiki/Wheel_sizing#Bolt_circle) is a little harder and requires a metric ruler. Sheldon (http://www.sheldonbrown.com/gloss_bo-z.html) always has good info.

Spindle interface is pretty easy, just look at the axle. For Shimano it's either going to be a square taper (I think this is what the RX100 used) or it'll be Octalink (Shimano's version of ISIS). Square taper has a smaller diameter axle and then as the name implies a square end that is tapered for a pressed fit into the cranks.
http://upload.wikimedia.org/wikipedia/commons/thumb/0/09/BB-UN73.jpg/250px-BB-UN73.jpg

Octalink uses 8 splines on a round larger diameter axle.
http://upload.wikimedia.org/wikipedia/en/thumb/d/d8/Shimano-octalink.jpg/150px-Shimano-octalink.jpg