Calculate number of chain links or belt teeth needed to compensate for lack of wheel adjustment
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
Using the current chain, you would have to move your rear wheel 12.24 mm 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. To find out how long you will have to experiment by changing the number of links. First try a chain with 95 links:
This still means moving the rear
wheel 4.26 mm to the front which is not possible.
This means moving the rear wheel 3.73 mm backwards which IS possible ! So a chain with 96 links would be long enough for this sprocket combination.
By the way, 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 link. (So keep the number of chain links even.)
For a belt the same calaculations 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.