WM-3 Rear Wheel Will Not Fit While Other WM-3 Did

[RobinV]

Hello all. I just cannot seem to figure this out. My 1978 Triumph T140 rear wheel is not in the best shape. So, I bought a used wheel that is better. Both are WM-3. The original one fits great. But the newly acquired one seems kicked way to the left. Almost like the rim is not centered over the hub. I thought I could space it to no avail.`The wheel is not centered in the fender. But is left side of fender.
Any one run into this? Never seen it before. Thanks.

 

[RobinV]

After looking more closely, I see that my newly acquired wheel rim is centered.
However the wheel I have been running has the rim off center towards the right.
My bike is a US import 1978-79. Was not aware that off center wheels were made.

 

[Don-Spada]

A T140 rear wheel rim should have an offset of around 14mm off to the right hand side, ie the centre line of the rim should be 14mm off to the right relative to the centre line of the hub. The rear rim should have 3 or 4 different spoke patterns (varying length and bend) to acheive this.

 

[Rudie]

The centreline of the rear tyre should line up with the centreline down the main frame tube. If you need to check this, unbolt the rear mudguard, stick a length of string to the top of the main frame tube by the forks, stretch the string down the centre of the main frame tube and over the rear tyre.

 

[RobinV]

Thankyou both. That makes sense. I just always figured that a motorcycle would be designed to fit a centered rim. In my case, the offset looks to be an inch and a quarter or thereabouts. I will have to clean up and reuse the original for now as I do not have the $ to build a custom wheel. Maybe next year, but I want to ride for now. Thanks again. Robin.