The drive belt alignment is often a bit of a compromise. You can get a straight edge between the front and rear sprockets to align them. The rear sprocket can be set to be straight in the chassis with the wheel alignment using a laser onto a target at the front of the car (details on the MTWC website). You can then check the front sprocket is aligned with that using the straight edge, although there isn't much scope to adjust the front sprocket other than choosing exactly where to secure the tube clamp mounts at the rear of the BB or elongating the holes at the front, neither ideal and only very minimal. You may have to sacrifice some of your rear wheel alignment to run the sprockets parallel.
The swing arm pivots can be adjusted to get things better as well by moving the swing arm left or right. Most seem to end up with the left side swing arm pivot almost touching the outside of the bevel box sprocket. If the belt is moving a lot from left to right on acceleration and deceleration (or reverse) then the alignment isn't great. The sprocket guides should be guides, not restraints. If the belt runs hard against any of the guides they will eventually break.
Any one for a chain drive?
