Back wheel offset

Since the swingarm is not offset to compensate for the cradle and front mount offset to the left then the centreline of the rear wheel should be appx. 1/4" off to the right viewed from the rear. The offset seems to vary from bike to bike. I have seen somequoted at 3/16" others at just over 1/4". My bike had 0.25" on the cradle and 0.31" on the front mount so I machined 0.060" off one side and added a spacer to compensate. Really the rear wheel offsetshould match the engine and trans offset whatever it is on your bike. The rear will then be aligned with the front wheel assuming the front is centred in the forks etc.

Keith is correct and you may find a discrepancy in the front and rear offset as he did. 750 frames are famously inaccurate. Establish that the front wheel is central in the forks. (Disc brake front wheels are difficult to build as there is hardly any dish on the disc side.) In addition beware of vernier adjusters not putting your isolastic mounts in the correct offset position (if you use vernier adjusters.) The swinging arm should be symetrical about the gearbox plates. In theory your wheel should be 3/16" to the right of centre of the swinging arm. That would mean a difference of 3/8" clearance between rim and swinging arm from left to right.

Google "the worlds straightest Commando" for some light reading on the subject.

If you have to lean to one side, that would indicate that the wheels are not lined up. I've just measured my 1970 750 and the engine and gearbox are 0.095" to the left of centre which is a lot less than I thought. I have a vernier on the front but shims on the rear. I've always struggled to line up the wheels and thought it was the incorrect offset in the rear wheel. Looks like I've got too much wheel offset, 0.1875" when I only need 0.095" Hmm. It's all coming to bits soon for a rebore and a frame check.