Wheel alignment

The wheel rim centre line needs to align with the steering head axis, which is in-line with the frame centre line. Fit appropriate spacers and/or move the rim by spoke adjustment. See, 'Front wheel offset', thread. Dosen't matter about the engine position. Rear wheel is centred to frame centre line by re-positioniing the iso assembly.

Previously Hans E Taylor wrote:

It has always baffled me when working on the front end of my Commando, of which there have been a few, why the front wheel is not central.

Let me explain. When viewed from the front, with mudguard removed the rim of the Commando front wheel is not central in the forks, and neither in line with the middle of the engine.I know the crankcases are not split centrally, but looking at the middle of the cylinders shows the same problem.

I have recently had a front wheel built with as much offset as possible and its still about 1/2 inch too far over away from the disc. Now before someone says I have the wrong spacers, the hub's position is dictated by the disc and its fitmentin the caliper. So am I going mad or do all Commandos have this anomaly ??

Hi Hans,

Any chance of some pictures ? Is this 'standard' brake / disk / rim ?

850 MKIII or earlier ?

Regards

Tony

As Simon said, the rim must be centred in the forks. There is also a factory service release (scan attached) which describes a '72 (RH disc) wheel having the non disc side spokes seated with a hammer. There is no mention how the wheel is otherwise built but with the correct length spokes and pattern (lh spokes to rh rim holes and vice versa) it is straightforward. Spoke to caliper clearance is marginal though but I have never had any issues with my builds.

The Norton front disc wheel is the hardest wheel to get correctly trued, get it right and there is no wheel you cannot true correctly. I have 2 to do but first I started with the BSA rear crinkle hub, then the 8" single sided front, next rear Triumph spool, last one the Triumph 8" TLS. So will give the disc one a go shortly.

Very few wheel-builders seem to have the correct information on the Commando disc wheel. The disc side spokes need to stand almost vertically.

It isn't helped by the fact that the angle of the spoke flange on the disc side is greater than it needs to be and if the spokes are laid flat on it, the wheel will not be central even assuming that they haven't allowed the spokes to bend.

On my current set-up which sits centrally, the 'off' side spokes lay flat on the flange but I can insert a .015" feeler between outside spokes and hub on the disc side. This is obviously dependent upon the spoke head but assuming that they are the same both sides, it gives an idea.

Any hint of the disc side spokes curving as they pass the hub flange indicates a badly built wheel.

The same principles of wheel truing applies to Commando's as any other motorcycle.

I'm no expert, but I do know the important factors are that the spokes have the correct length/type/angles and, as equally important, that the rim spoke holes have been drilled to the correct angle to suit the hub, Doug Richardson does this.

Many rims are only pierced as standard, which is not always at the correct angle. Subsequently they are difficult to true and fitted spokes have an 'S' shaped bend along their length between rim and hub. Obviously they should be straight.

"Previously K Glassborow wrote:

As Simon said, the rim must be centred in the forks. There is also a factory service release (scan attached) which describes a '72 (RH disc) wheel having the non disc side spokes seated with a hammer. There is no mention how the wheel is otherwise built but with the correct length spokes and pattern (lh spokes to rh rim holes and vice versa) it is straightforward. Spoke to caliper clearance is marginal though but I have never had any issues with my builds."

Thanks for the factory service attachment.

I recently fitted a new stainless rim and spokes to my Mk3 front wheel. When I had trued it, I saw that there was a curve to the spokes mentioned in the service bulletin, so I used a hammer to straighten them, before re-tensioning.

It seemed the obvious way to resolve the problem, although at the time I had assumed that the new spokes had been made incorrectly.

It's nice to know I adopted a genuine Norton factory technique!

If you re-centre the rim, make sure that no spoke is exposed beyond the nipples, or it will cut into the rim tape and cause a puncture.