[Yak] inner chainring

[John S. Allen]

At 10:10 PM 12/16/2007, Geof Gee wrote:

>I measured the distance between
> > teeth
> > at 13 mm (I assume that it must be close to 25.4mm/2 ... probably
> > depends on whether you measure it at the tip or the base).

the half-link spacing of a new bicycle chain is 1/2 inch, or 12.7 mm. 
The diameter of a sprocket at the centerline of the chain is 
approximately that divided by pi. (the actual path of the centerline 
of the chain is polygonal rather than round.) Sprocket teeth reach 
above the centerline of the chain by a variable amount but typically 
no more than 0.2 inch or 5 mm, increasing the diameter by twice that.

John S. Allen

Regional Director for New York and New England, League of American Bicyclists
League Cycling Instructor #77-C and Member of the League's Education Committee

http://bikexprt.com