Rear Wheel centering

I need to rispoke the rear wheel.
I would like to know if the rim is perfectly centered (is cambered the correct word?) with the hub (without sprocket/drum) or if it is moved to one side.
I dont want to spoke about the offset but only to the centered of the rim/hub.

I know, I already asked the same thing in another earlier topic, but I have no clear ideas.
I think that is not perfectly centered in the middle of the hub because the inner spokes are not equal to the outer spokes (maybe?).

Ciao
Piero

Drum brakes are close to centered on hub. You can install spokes loose and fit wheel on bike and adjust spokes to center on main spine. I built my wheels on a jig and then installed and adjusted spokes one side and the other to move a couple mm. I also made a mark on the web between the shock tops for center of bike (large tube), but you have to be sure the wheel is straight in line with the large tube also (chain adjusters). Easy if no shocks installed, you can pull the rear wheel up above the main tube and use long straight edge (florescent tube) to compare with main tube all the way up to headstock.

Dave

Amend to Dave's final fit to fiddle the spoke tensioning but why not just do it on the bike as no doubt about where things align, more convenient mount points for a dial gauge and a wire pointer. With bike propped up nicely it hardly could be more comfy on an appropriate stool to extend your quality Commando fettering time up close to your object of worship in ancient accepted humbled bowed posture. I did not find forks or shocks to get in tmy way at all so a small lazy boy relief there too.
If only there was not a such conflict between spoke torque, centering rim and in frame or getting each same length row to similar tension tone. It will never be easier to give spokes & nipples a nice polishing all over than when loose in hand and rim too.

I still think it's a good idea to measure the distance between the sprocket centreline and rim centreline.
That should be the same distance as the gearbox sprocket centreline from frame centreline,if wou want to have the rim centred and the sprockets aligned.If it's not the same distance,you will never have sprocket alignment when the rim is centred (and vice-versa).

Like many others,I don't believe having the rim exactly centred gives the best results.If the rim is slightly offset toward the heavy side of the bike (about 1/16" toward the primary side) it does no harm.Some manufacturers deliberately offset the rear wheel from the frame centreline.

In the end the rear wheel must align with the front wheel, so if you have to turn it in the swing arm or pull the rim over a bit or use spacers, so be it. Spoke it up then use a string line, don't cut ends of the spokes off until you get it right. It is not rocket science.

From page 231 of Roy Bacon Norton Twin Restoration- "The Commando has its rear rim off set about 3/16" to the right to allow for the engine plates being offset by that amount to the left.Thus the wheel is not central in the rear fork."
Brett

Sometimes the rear chain creates the need for an offset. If you fit fatter tyre, sometimes the chain will rub on it and turning the wheel in the swing arm to stop that makes it difficult to align the wheels. If you end up with the wheels both pointing in the same direction but stepped out alignment , the bike becomes stiff when ridden.

I used this with runout centering and balancing not to mention offset when I spoked my new excels.

Rosey said:

From page 231 of Roy Bacon Norton Twin Restoration- "The Commando has its rear rim off set about 3/16" to the right to allow for the engine plates being offset by that amount to the left.Thus the wheel is not central in the rear fork."
Brett

Click to expand...

+1

The Commando rear wheel is indeed offset as Rosey says. The tires are aligned with a straightedge while tensioning the chain.

Measure your existing setup before you take it apart. Tony

I am about to build new wheels for my Norton project. The wheels I had ran perfectly true and I'm certain were factory built way back when. What I did before taking them apart and off the hub, was laid them down on a flat surface and and took a measurement from the surface to the center of the edge of the rim. I did this for both front and rear rims. I just got the rims back from powdercoating ,polished the hubs,and bought spokes from Buchanans. So I'll be building them this week. With the cushdrive side on a flat surface the center of the rim edge was 21mm off of the table .With the disc brake studs sitting on the flat surface the center of the rim edge was 33.5 mm Remember this is to the rim edge not the wheel center...Hope this helps......Skip