Rear wheel offset

Hi guys, recently took the rear wheel off too check for balance and offset. Does anybody have the offset measurement to hand so that I can check?

my tyre had been rubbing on the mudguard riding two up hence the need to check it. (the guard was central to the frame)

bikes a 74 850 if it makes a difference

The power unit is offset 1/4" to the starboard of the frame cl, iirc. The rear mudguard can actually be tweaked and should not be used as a true point of reference for locating the rear wheel. Check the wheel alignment front-to-rear with 2 long straightedges for a better idea of what's actually there. There are likely a few threads discussing the appearance of misalignment when comparing the fender to the wheel. There are also threads concerning hub-to-rim offset, if that's what you're looking for.

You may need to crank up the rear preload for 2-up.

Adam_R said:

recently took the rear wheel off too check for balance and offset. Does anybody have the offset measurement to hand so that I can check?

Click to expand...

The correct amount of offset will be whatever it takes to position the rear rim on the frame centreline so I recommend you at least check this yourself rather than rely on a standard measurement.


https://www.nortonownersclub.org/support/technical-support-commando/wheel-offsets

it did appear to be central before removal, I just wasn't sure if the hubs were supposed to be central to the rim or offset.
I've popped it on the tru anyway and it's spinning perfect, so it looks like cleanup and put back on job.

If your back wheel is hitting the underside of the mudguard check the shocks, as an example on Koni's they limit the movement to the required amount by including spacers under the bump stop. The spacers can split and then allow too much movement, I have a set that went that way. Regardless of the pre load the shock movement on the original shocks was set so as not to allow the tyre to touch the mudguard, aftermarket shocks that fit but are not exactly specified for the Commando can allow too much and need to be swapped out.

thanks for this, it could probably and more likely be the problem.

This is sort of arse about but having just been doing this it would appear that the front wheel is problematic. I unfortunatley have no experience on the 850, your disc may well be on the left, but with my 750 (disc right) it is difficult getting the off set right. This is (I defer to experts) as I understand it because you have an almost vertical spoke disc side. So using different guage spokes and having different torque settings is order of the day. Once the front is set right (centred in the forks) you have a reference for the rear. I think on the RGM website there is info on offsets taken from various wheels which might provide a reference point if nothing else. I have been also looking at wheel alignment on my Seeley Mk4, more string, plumb lines and straight edges than you can shake a stick at, giving me brain ache, good luck.