This is going to possibly be the dumbest question ever!
OK, once I get my rear sprocket to line up with the gearbox sprocket on the pre-unit, and the wheel sits nicely in the swingarm, the wheel is offset from the centreline of the frame by almost an inch to the drum side!
This is not normal, and might surely kill me, right?
Don't know if this will help, but I had a similar problem with my '76 T140V Bonnie. I know, completely different bike but, I had a seriously offset rear tire, so close to the sprocket was the tire that I couldn't hardly fit a matchbook between the chain & tire, let alone a chainguard. I finally discovered after installing a newer rim and stainless steel spokes, that a PO had laced the wheel backwards. How do I know it was he, and not me? I replaced spoke for spoke, one at a time (due to 4 different sizes). Well, when I (thought I) was done, the chain wouldn't fit at all. Only then did it dawn on me that it was backward from the start. I got it sorted out, and now there is sufficient clearence for the chain, and I now have a chainguard to boot. Oh, I was also able to remove a "shim" washer on the rear caliper which was needed in order to make that work. The tire still looks kind of offset, but at least it work better now. Maybe someday I'll get it figured out completely. Hope this helps, Jersey Kev
67 TR6P Saint 76 T140V Bonneville 95 Daytona 900 (removed non-brit from list)
I don't know why people insist on using some part of the hub (which may or may not be in its ideal position) as a reference point for wheel-building.
If you have a Triumph 500/650/750 unit or pre-unit and its built with standard parts,the centreline of the gearbox sprocket and chain is 3" from the frame centreline. So if the centreline of the rear sprocket is 3" from the rim centreline,a 1950 Speed Twin would be happy with that.If the chain is aligned ,the wheel will be centred in the frame.
Because unit engines are noticably heavier on the primary side (with alternator,duplex/triplex chain,and a heavier clutch),I shorten that centre to centre distance to 2-15/16". The chain stays aligned and the rim moves slightly toward the weight centre (primary side). This keeps a unit happy.
Funny you should say that John, I have that Wheel Lacing Info up on my blog, as you suggest it give 2-9/16 as the correct measurement when in reality it needed to be set at 2-1/4, at this measurement the Rim is perfectly centered, here is that chart that I should probably remove from the blog if not amend it.
If you decide to press it straight,put some neat-fitting pieces of solid shaft into the bushes to stop that area being squashed out-of-round. If you're straightening it,over-bend it first to destroy it's memory;then press it back a little to the final straight position.