Wheel truing with ts-2.2 - rims not centered in caliper

Gadaffi

Just got a new Park tool ts-2.2 truing stand, never trued a wheel in my life - but we've all got to start somewhere.

The question is :I have mounted 3 different rear wheels in the truing stand, all near enough true, however the arms on the caliper are not centered on any of the wheel rims - there is always a larger gap on one side or the other. This is a brand new stand so I don't expect it to be out. I though that the rims would be centered on the axle but it seems none of the 3 I tried are. Is this normal?

If the caliper is not centered on the rim do I just use one of the caliper arms to tru and not both?

Here are some pics that I hope shows what I mean.

schweiz

The rim should be centred between the calliper.

Either the dishing is wrong on all your wheels or the truing stand needs to be calibrated using something like this...

http://www.chainreactioncycles.com/Mode ... elID=34748

[edit]

just looked at you pictures again and noticed that the rim isn't always off centre in the same direction so at least one of your wheels isn't dished properly (it could be both the dishing of the wheels and the calibration!)

Gadaffi

schweiz wrote:

The rim should be centred between the calliper.

just looked at you pictures again and noticed that the rim isn't always off centre in the same direction so at least one of your wheels isn't dished properly (it could be both the dishing of the wheels and the calibration!)

Thanks schweiz - I've just put another rear wheel in the stand and the calipers are only very slight off this time, its a relatively new xt wheel that hasnt taken the abuse of the other wheels - the others are either race or training wheels that are used a lot.

How much effort is needed to re-center a rim (considering that the wheel is true laterally ) and what is the consequence of leaving the wheel with the rim off centre?

here is the xt wheel in the stand:

benpinnick

The consequences are limited, as running wheels off center and not even knowing will have shown you.... The main issue is tyre clearance at the back, and slight pull on the front. You're best off calibrating the wheel jig with your XT wheel, and going from there. Centering a front wheel is easy enough, just slightly loosen the spokes on one side and tighten the other until straight. When I say slightly though, I mean it! only 1/4 turn on the nipple at most each time. Patience is better than speed here.

On the back its slightly harder, as the drive vs non drive spokes will be at different tensions (which over time can lead to undishing of a wheel). Most rear wheels tend to drift towards the disc side over time if they undish. This means that you need to be conscious of how much tension you are letting out of the non-drive side to get the wheel dished again. Not really tricky, just a different problem to solve.

benpinnick

PS - Its best to have a seprate dish checker I find, as the wheel jigs are not so good for this, as the arms tend to flex and mean that a wheel that looks dished could still be out. I have a neat little minoura dishing tool I got for around £30.