gear inches
 

May be a silly question---If I mix and match cogs and chainrings,if the gear inch value is the same,will that mean that the chain length will work for all combos?(I have converted a multispeed)
Tx

no. the combined cog/chainring tooth count will need to be constant (or at least close to it) if you want to use the same chain.

Let say you have running a 48/18 ratio, it has a gear inches of 70.3 with 23c tires, but 43/16 gives you about 70.6.
That's a huge different in chain length, you have to shorten/lengthen your chain to make it work.

Tx guys---clear now:)

48/15, 16,17,18,19 and 46/19 - using the same chain length. Depends on where your axle is at in the dropouts.