Thought of making a rear wheel alignment jig recently, until I asked DAGAD (legendary dude he is) look over the plans for me.
His method is much simpler, and I've adapted it a bit to locally available bits.
A length of 3/8" threaded rod about 20" long, with 4 nuts and 4 washers. Bent 2 x 4" lengths of steel wire into an eye at one end, to go on the rod, and a straight pointer (sharpened) at the other.
Use nuts and washer to secure one eye pointer at the very end of the rod. Set the other one near the other end, but do not tighten. Parts cost me $6.
Centre punch both ends of the the swing arm axle and the rear wheel axle. Put the fixed pointer on the swing arm axle centre piont, and adjust the free-moving end to the centre of the rear axle. Adjust till both sides are the same.
Jim's spot on with the chain play.
Hope this helps.
Pete
