speedometer ratio

[cdav59]

If I'm changing out my speedo how do I determine what the ratio is, and does the ratio really make a difference ......bike is a 1985 vt500c.

 

[teddpage]

Is it cable driven off of the wheel?
If so, remove the cable. Turn the wheel exactly one revolution (mark the tire where it meets the ground), and count how many times the speedo drive turns.
So if the speedo drive turns 4 times for one revolution of the wheel, its 4:1.

 

[MotoMadness]

Assuming its the stock wheel, you should be 60:2240 ratio. 60mph @ 2240 Rpm

 

[cdav59]

thanks guys i tried the spinning the wheel technique and the speedo cable rotated twice for every one turn of the wheel, then i looked at the back of the speedo and it said 2240@60.....rookie mistake my bad but thanks for the info