v7 sub

Calculate number of chain links or belt teeth needed to compensate for lack of wheel adjustment space

When there is no more room for adjusting the rear wheel in the right direction, the only option left is to alter the chain or belt length, i.e. the number of chain links or teeth of the belt.

Suppose you want to switch your sprockets form Current (14-36) to Custom (15-38).
This means the following sprocket distance change:


Using the current chain, you would have to move your rear wheel 0.49 inch closer to the front. Now lets assume the rear wheel is already at the maximum front position. This means the only option is a longer chain. A longer chain means a New chain for which the wear percentage is 0% (as it is new) so change the wear percentage for Custom to 0% and start experimenting with a longer chain: To find out how long you will have to experiment by changing the number of links.

First try a chain with 95 links. By the way, that would not be a realistic # of links as it would require a special connection master link due to the total number of links being odd but for this example it works:

This still means moving the rear wheel 0.28 inch to the front which is not possible.
So now try a chain with 96 links:


This means moving the rear wheel 0.04 inch backwards which IS possible ! So a chain with 96 links would be long enough for this sprocket combination.

As mentioned above, normally the minimum increase or decrease of chain links is 2 as you do not want to remove 1 link and replace the ends with a special connecting master link. (So always keep the number of chain links even, this is including the master link.)

For a belt the same calculations can be done for determining the number of teeth needed in the new belt. For a belt the number of teeth can be odd as a belt has no 'conection link' like a chain does.

Next: Chain Links Calculator for Generic Final Drive with new chain

Next: Decide on whether to get smaller front sprocket or bigger rear sprocket

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