Wheel offset

There is no off-set on either the front or rear Dominator wheels. Both rims should run central to a line passing along the centre of the frame and through the steering head. The Norton Factory set a maximum target of less than 2mm deviation from this datum line for the front and rear wheels.

The front rim should run central to the front forks with an equal clearance on each side. Generally the rim is close enough to the mudguard bracket boss to enable a ruler to measure this gap. I seem to recall that you could take the front wheel out of the forks, remove the brake plate andif a standard Dunlop WM2 chromed rim was fitted, run a straight edge (long ruler)across the drum edge. If all was well, the straight edge would touch the drum and both rims with next to zero gaps anywhere at the 4 points of contact.

The rear wheel is a bit harder to check. Especially if still in the swinging arm. It too should run centralin the two legs. But this is difficult to check unless you know the wheel is smack on the datum line mentioned above. However, if the front wheel is true and the frame not bent then it should be possible to get the rear wheel in line with the front and then check the rim is central in the rear fork.

Again I believe that with this wheel off the bike and the drum sprocket removed, a straight edge test could be made from rim to rim across the drum mounting bosses. The rim has to be RM2 size as per the front. Perhaps some one can confirm this?

I think you might be comparing apples to oranges here. Peter was asking about hub/rim offsets - presumably in relation to wheelbuilding,but Phil is talking about rim/frame offsets. I have never built or rebuilt a wheel but I know that some have assymetrical hubs. The offset from the edge of the hub to the rim edgecan be different on each side ofthe wheel. Wheelbuilders will tell you as they talk about offsets - Over to you Anna!Front and rear rims HAVE to be in line or they fail an MoT - if you need one!

Cheers, Lionel

Previously peter_elton wrote:

Previously phil_hannam wrote:

There is no off-set on either the front or rear Dominator wheels. Both rims should run central to a line passing along the centre of the frame and through the steering head. The Norton Factory set a maximum target of less than 2mm deviation from this datum line for the front and rear wheels.

The front rim should run central to the front forks with an equal clearance on each side. Generally the rim is close enough to the mudguard bracket boss to enable a ruler to measure this gap. I seem to recall that you could take the front wheel out of the forks, remove the brake plate andif a standard Dunlop WM2 chromed rim was fitted, run a straight edge (long ruler)across the drum edge. If all was well, the straight edge would touch the drum and both rims with next to zero gaps anywhere at the 4 points of contact.

The rear wheel is a bit harder to check. Especially if still in the swinging arm. It too should run centralin the two legs. But this is difficult to check unless you know the wheel is smack on the datum line mentioned above. However, if the front wheel is true and the frame not bent then it should be possible to get the rear wheel in line with the front and then check the rim is central in the rear fork.

Again I believe that with this wheel off the bike and the drum sprocket removed, a straight edge test could be made from rim to rim across the drum mounting bosses. The rim has to be RM2 size as per the front. Perhaps some one can confirm this?

thankyou very much phil for the information appreciated

OK. Point taken.........Perhaps the following will help make things a little clearer.

On all the bikes with full width hubs........the rims were symetrical to the hubs when viewed from a rim edge inwards. The centre of the rim should coincide with the centre of the drum between the spoke flanges. So the spoke lengths should be roughly equal on both sides of the drum.

On the early 50s bikes with half-drums, obviously the respective spoke lengths willnot be equal. Same applies to Manx conical hubs.