Rear sprocket diameters

[426 NOOB]

Has anybody ever done measurements on a rear sprocket to see what a difference 1 tooth makes in the sprockets diameter? Just curious as to what the diameter difference would be going from a 52 to a 51 tooth. My guess would be 1/8 inch.

[grayracer513]

Has anybody ever done measurements on a rear sprocket to see what a difference 1 tooth makes in the sprockets diameter? Just curious as to what the diameter difference would be going from a 52 to a 51 tooth. My guess would be 1/8 inch.

Do the math:

You know that the pitch of your 520 chain is 5/8". That being the case, a 52 tooth sprocket will have a circumference of 52x.625=32.5", and a 51 would be 5/8 shorter at 31.875. Dividing by Pi, that gives you 10.345" and 10.146" respectively for the diameters, and the difference is .199", or just over 3/16".

[426 NOOB]

Do the math:

You know that the pitch of your 520 chain is 5/8". That being the case, a 52 tooth sprocket will have a circumference of 52x.625=32.5", and a 51 would be 5/8 shorter at 31.875. Dividing by Pi, that gives you 10.345" and 10.146" respectively for the diameters, and the difference is .199", or just over 3/16".

damn, gray you are smart. I would have never figured out how to do that. Thank you.

[grayracer513]

Geometry 101

They told you you'd want to know it later.

[CaptainKnobby]

Geometry 101

They told you you'd want to know it later.

Yeah!.....but how do you still remember it after all those years?

All those formula's?

[grayracer513]

If you just remember that they exist, you can look them up when you want them.