Getting the wheels on square!

[Paul Townsend]

I hope I'm not hi-jacking this thread, but at present I'm a bit concerned about my GW wheel press as I fear it may not be entirely accurate. First, I have been under the impression that when a pair of wheels are quartered using the press, one should then be able to look through the spokes of one and see that they line up with the spokes of the other. That doesn't happen with me. And secondly, I was under impression that I'd get an accurate 90 degree "quarter" - again, that doesn't happen and it can be a few degrees out (and at least one of the wheels is quite likely to be wobbly on its axle). Looking at the press it seems fairly indestructable, but if the results I get are indeed not what they should be I can only think that I may have dropped mine or damaged it in some way.

DT

Exact 90 degree does not matter. What is vital is that all wheelsets are the same which your jig would achieve OK.

If you think your jig is forcing wobbly wheels, that implies the inner faces are not parallel. Mine is inaccessible just now so I cant check the practicality of this but if it is possible to slide the outers in until they touch that would reveal any machining errors. If you had some error, I am sure George would replace it. If parallel when together but not when 20mm apart that suggests bent guides (due to drop?). AFAIR they are lok-tighted into one side. Maybe heating and pulling would allow removal and replacement of the guide(s). Having said all that I would have thought a bent guide would cause extreme stiffness in sliding.

Edited as I just saw Rob's comment re bosses:
I agree that spacers to ensure the rim is in contact with the jig are needed if you have bosses on wheels, plasticard is adequate.
Ensure the plasticard cut edges are deburred before sticking on. Use Mekpak etc and it is easy to ping them off again if you want.

[Philip Hall]

Like Paul, I doubt your GW jig is out of true unless it's had a bad knock. Spokes will only line up when looking through them if the spokes are at 90 degrees to the other side, and they might not be in relation to the crankpin position; what matters is that the cranks are at the same angle, 90 or 89 or 91.

If a wheel wobbles, it may not be the way it's been put on the axle. If it's a AG wheel, the tyre may have moved on the centre, which is why I usually check that the tyre is concentric to the hole in the middle and also exactly at right angles to the hole. Such checks are not possible for everyone and by and large most of us do very nicely without doing so, but I like to as it adds that extra little bit of precision to the process. AG wheels are also a bit bendy by nature, so if the front of the boss is also not at dead right angles to the axle hole (and that is possible) then the push on with the GW jig could render a wobble. It is for this reason that I sometimes add shims around the tyres, so that although the pressure is at the centre, on the boss, there is some support for the tyres which may help to prevent them moving.

Philip