Truing wheels

[Chris S]

I've just trued my wheels to within 2 millimeters.

When I rotate the wheel and compare the edge against a fixed point such as a brake block some parts of the rim appear slightly below it an others above it. The difference can't be more than 3mm.

Is this acceptable and if not what's the best way to fix it?

 

[brockers]

I've just trued my wheels to within 2 millimeters.

When I rotate the wheel and compare the edge against a fixed point such as a brake block some parts of the rim appear slightly below it an others above it. The difference can't be more than 3mm.

Is this acceptable and if not what's the best way to fix it?

A 3mm 'hop' isn't disastrous, but I wouldn't find it acceptable. Sorry to say, but the best way might be to slacken off all spokes (or at least the half of them on that side of the wheel) and start again. Bottom line is, truing wheels in the frame using brake blocks as a guide is rarely going to give perfect results.

 

[the snail]

I think it's best to centre the wheel by tightening spokes, so if the spokes are tensioned already then probably best to slacken the spokes ( not completely, I'd try half a turn each) then tighten the high spots. I'd disagree with brockers, you should be able to true the wheel very well in the frame, and to better than 2mm of wobble. Work methodically and keep at it until the wheel is true, and crucially the spokes are evenly tensioned. It took me a couple of attempts, but I managed to get mine true, and they've stayed good for several hundred miles now, so if I can do it, anyone can!

 

[accountantpete]

You are out of true vertically - a 3mm error is pretty bad.

It means that the spokes on the section of the wheel that go under the fixed spot are over tightened and those on the other side may be under tightened.

I'd slacken the former first - just by a 1/4 turn and see how that works.

 

[gwhite]

After adjusting for radial trueness, it's as well to check the dish.

 

[screenman]

I would say it is extremely important to check the dish.

 

[MontyVeda]

I'd just take them to a bike shop to get them trued by somebody who does it regularly... it's more of an art than a science and doesn't cost the earth if you go to a decent LBS... the last time i got my wheels trued it cost around £6 in 2002

 

[brockers]

I'd just take them to a bike shop to get them trued by somebody who does it regularly... it's more of an art than a science and doesn't cost the earth if you go to a decent LBS... the last time i got my wheels trued it cost around £6 in 2002

I'd echo this. Last time I took a rear wheel (with what I thought was a pretty wobbly and worn-out rim) in to a shop, I expected the ex-works mechanic to tell me I needed a new rim. He inspected it, told me the rim still had plenty of thickness, and trued it down to under .5mm. Twenty minutes work and a tenner. Job done. I find it a HECK of a lot easier to get perfectly round wheels when you have a proper wheel truing stand.

Absolutely no harm in giving it a bash (and I wholeheartedly encourage everyone who's worried about any aspect of bike-wrenching to get stuck in and give it a go), but there's absolutely no shame in admitting partial defeat sometimes, and giving the task to someone who's done it a hundred times before !