WHAT IS BCD MEASUREMENT ??

[BADGER.BRAD]

[FONT=&quot]I have contacted the place where I brought my bike (Edinburgh cycle co-op) with regard to fitting a second chain wheel to my Courier classic hybrid. They need to whether the cranks arm is a 4 or 5 arm (that makes sense) and asked for a BCD measurement!! What is a BCD measurement?

Many Thanks All.

Brad[/FONT]

 

[BentMikey]

Bolt Circle Diameter:

http://www.sheldonbrown.com/gloss_bo-z.html

 

[BADGER.BRAD]

Thanks for the help Mikey, much appreciated.

Brad