Global-flat.com Board

English => Parts & Bikes => Topic started by: ancientskool on February 22, 2010, 06:22:33 AM

Title: Diameter of Sprocket Calculation?
Post by: ancientskool on February 22, 2010, 06:22:33 AM
Is there some calculation you can do to figure out the diameter of a sprocket if you know how many teeth it has?


??????

I'm sure I'm not the only one who has ever wanted to figure this out!
Title: Re: Diameter of Sprocket Calculation?
Post by: JUGGARNAUT on February 22, 2010, 06:27:46 AM
In inches, every pin is 1/2" from 1 to the next. so a 44 t = 22" and so on.........
Title: Re: Diameter of Sprocket Calculation?
Post by: ancientskool on February 22, 2010, 06:43:09 AM
In inches, every pin is 1/2" from 1 to the next. so a 44 t = 22" and so on.........

My math skills aren't the best, but that would give you the circumference right?

Let's assume a 28" sprocket - I don't think it's diameter would be 14".  I just measured the one I have and it's between 4 and 5" (hard to measure on a bike with the cranks on).

Circumference = Pi (Diameter)?

So, Circumference/Pi = Diameter?

So, a 28 tooth sprocket would have a circumference of 14" and a diameter of 4.46"?  (28/3.14)?

That seems about right.
Title: Re: Diameter of Sprocket Calculation?
Post by: JUGGARNAUT on February 22, 2010, 07:03:26 AM
oops. Yeah thats for Circumference.
Title: Re: Diameter of Sprocket Calculation?
Post by: SERGI8 on February 22, 2010, 02:23:41 PM
Yes, you are not the only one. Here you are

(http://img694.imageshack.us/img694/3235/diamc.jpg) (http://img694.imageshack.us/i/diamc.jpg/)
Title: Re: Diameter of Sprocket Calculation?
Post by: ancientskool on February 23, 2010, 02:03:04 AM
THanks guys!