how to determine chain length

[joe_f7]

on my tecate i have a longer swingarm and bigger rear sprocket. i have a 42 tooth rear sprocket with a 106 link chain. i want to go down to a 37 tooth sprocket. do i measure the difference in sprocket diameters and length of a link and subtract? or whats the best way to do it?

[rdlsz24]

This was posted earlier today. Not sure if it will be useful in this case or not. http://www.3wheelerworldforums.com/showthread.php?t=99955

Rob

[joe_f7]

i saw that, but i wasn't sure how accurate is was. i think my swinger is 3" over. that would make a 104 tooth chain according to their numbers with stock gearing which is what i'm switching back to. sounds close but i don't have a exact number my swinger is over.

[dcreel]

Buy too long of a chain and a chain breaker, then cut it to length.