chain/sprocket sizing

[smoker]

does there exist a chart or something for adjusting your chain size according to your sprocket size?  I've got a 15t in front and will probably get a 42-44 in the back.  I did a few searches for this info but didn't find much??.....

[werase643]

common sense....
down 1 and up 3-5....
2-4 links longer

[smoker]

So...
By that reasoning, minus 1 tooth front plus 3-5 rear corresponds to the same total number, 2-4, links added to the chain.
It would seem to follow...
Since standard front spkt. is 16 tooth, I think, and standard rear is 39 tooth, total is 55, that would imply a 55 link chain.  But standard chain lenght is 110, again, I think... 
So math says a factor of 2 relates total number sprocket teeth to chain links, as opposed to common sense's 1 to 1 ratio.  Thanks for your help tho man...  Anyone really know what size chain I should buy?

[l3uddha]

I went up 6 teeth on the rear sprocket & went with a 14 tooth chain. 15 would have worked too; 16 (that I bought) was too long.

You're better off getting a few links longer & cutting it down. I used a grinder to cut it & punched the pin through with a screwdriver.

[gsJack]

Playing with this Tsubaki calculator a few minutes, I came up with an ideal center distance of 25.697" for the standard 16/39T and 110 links.

A few more minutes yields an ideal center distance of 25.787" for 15/43T and 112 links.

Works for me.  Your bike, your money, your choice.   

Have fun.

http://tsubaki.com.au/tsscs/chain_length.htm

[smoker]

Thanks... that calculator is just the trick. What are and how did you determine 'chain pitch' and 'center distance'?

[gsJack]

A 520 chain has a 5/8" pitch indicated by the "5" and is 2/8" (1/4) wide between plates indicated by the "2".  Use .625 pitch to calculate.

I just guessed about 24" center distance and a couple tries came up with the 110 links and approx 25.7 center distance for 16/39T.  Just use a 25.5" center distance to calculate for the new sprocket sizes. The calculator will yield the number of links and the new ideal center distance.

[melloGS]

I have 1 down 2 up, and the oem chain size is good.