H: Hubs, Wheels and Tyres How much run-out for rims

Robert Watson

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I have built in the neighbourhood of 25+ rims. Vincent, BSA R3, Nortons etc etc. best I ever did was on original Velo Thruxton flanged Dunlop rims, both ends easily under 10 thou in both directions. I usually work at them until they are close and then give all the spoke heads a light tap and leave them overnight, store up some patience and finish up the next day. 15 thou is about my max and ignore the jump where the weld is.

On the last set of Devon SS rims I did it was very difficult to even find the weld.

Some just fall together in the right spot and others like to fight you all the way. A recent certain model 7 rear with used rim and spokes was a prime example of that........ the patience bank is still a little short!
 

Chris Launders

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I managed to get my Norvin rims (they were akront rims, fitted in the late 80s) to below 10 thou in both side to side and round. Beware of powder coated hubs and rims, the spokes will settle into the powder coat and will want doing more than once.
 

Albervin

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Thanks guys. I am down to about 10 though run-out side to side. A bit trickier getting roundness down but I haven't given up, yet.
 

Robert Watson

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Roundness is your friend, much easier to balance!

I got a Comet that you could not ride, at 50 MPH the rear wheel literally bounced off the ground and the front was a 410 - 21 which had a mind of its own, and when I asked how true the wheels were the PO said he had done them close to 1/8 run out. It had very wide bars on it as you needed them to try and turn the front wheel. They are still a bit long even tho' I took 3 in off the, changed the front to a 300-20 and trued the rear to something reasonable and balanced the whole plot
 

vibrac

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Another thing to consider is getting the hub centered in the rim side to side. Use a long straight edge across the end of hub and check distance to rim edges top and bottom, front to back etc. then check the other hub end.
When I had to renew the front wheel spokes on my long term project a BMW defazio hub center steerer I was faced with rebuilding a wheel without a fixed axel I found an article in the vintage motorcycle workshop which described a 'taverners jig' basically a true wheel is placed in a horizontal jig and the spindle ( hub in my case) is located in relation to the rim in all planes. I made mine with a slab of kitchen worktop angle iron and studding renewed all the spokes and tried it with a spanner and spoke tune since the final truth needed to be in the front swinging arm and include the steering bearings I was very happy with the 30 thou run out as it's a hub steerer it does not need fork accuracy. Lots of articles on the web I was told that all BSA wheels were at one time made this way to deskill the job. I guess with a conventional wheel you could easily do a final true ( if needed) in the forks
 
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