Trueing a wheel
My winter bike/commuter is getting battered by the daily abuse/potholes and both the front and rear wheel now have a slight 'wobble'
How hard is it to true a wheel ?
Can anybody offer any advice or point me in the right direction? I could just drop the wheels off at my LBS but then I'm out of action, and to be honest, I like to try and do things myself...
Cheers...
How hard is it to true a wheel ?
Can anybody offer any advice or point me in the right direction? I could just drop the wheels off at my LBS but then I'm out of action, and to be honest, I like to try and do things myself...
Cheers...
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Comments
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AntLockyer wrote:
That will do nicely... Will give that a go Saturday morning... Cheers...0 -
I thought I could do it myself but ended up making the wobble worse so took it tio the LBS.0
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Trueing a wheel so that it runs laterally true is very easy - look at Park Tools or Sheldon Brown to find out how. All you need is a spoke key and a couple of zip ties ot two spare spokes and nipples (tape them on the forks nipple end towrds the rim so you can slowly unscrew the nipple closer to the rim as it gets truer - genius idea someone on here came up with)
Getting the wheel round takes more skill and time and most home-truers don't even think about it let alone do it. Unless it's well out of round it is not a great problem
Getting the spokes acceptably and evenly tight, whilst maintaining lateral trueness and roundness is harder still, but easily achieveable if you take the time to read abouthow to do it and take your time.
Loose or unevenly tensioned spokes make the wheel weaker and more prone to broken spokes and eventual failure. If your wheels have a hard life or you need them to be reliable (i.e you tour abroad or ride long overnight audaxes in Welsh mountain widerness) it's best to do it properly or take it to a good LBS.
A decent trueing stand an tensiometer take the guesswork out of it fi you can bear the investment - they will last a lifetime of cycling if you look after them.0 -
A good truing stand makes the job easier. That's the good news.
Good truing stands are not cheap. That's the bad news.
However, once your get the hang of it you won't have to pay the bike shop.
Dennis Noward0 -
A truing stand is the best thing, but for the odd repair you can hook the saddle or bars on something so that the respective wheel is off the ground, and use the brake as the reference. I've even used that for rebuilds though it's not ideal.
The rest of this answer could be demonstrated in thirty seconds but takes long paragraphs to explain - sorry if it's all gibberish, I could show you a lot quicker!
Bear in mind before you start - if you're happy with the overall tension of the wheel, try not to overdo the tightening of spokes on average. It may have gone out of true because of something loosening, since spokes don't tighten themselves, but mostly try to make sure you undo as many turns as you do up, otherwise on average the wheel gets tighter. E.g. if the rim wobbles to the left, loosen a left-hand spoke as well as tightening a right-hand one.
As said above, up/down wobble is less relevant unless it's pretty bad. For a strong wheel, spoke tensions are almost more of a priority than a true rim. Assuming you're not building radial, spin the wheel, hold it in front of you so your eye is on its plane (i.e. if a bit of mud flew off the rim it would get you in the eye...) look past where the spokes cross, and see which "crossings" sit further out than others. If at the point where they cross they're further out then the inner spoke must be tighter, and vice versa. With the wheel in the wheel jig/bike, hold a coin near where the crossings are, spin the wheel, and the spokes that hit the coin are the ones that stick out so you tighten the outer and loosen the inner, then when you've got it so that most of them hit the coin, the ones that still don't are the ones that are still too far inwards so tighten the inner and loosen the outer. I use a coin simply because the spokes rub past it without it getting caught or damaging them as a screwdriver might do. Holding it by hand isn't that reliable but if you keep as still as possible it's good enough.
Radial wheels are harder in that respect - or any wheel where the spokes don't cross, e.g. Khamsin - a front I bought recently started rattling on the first ride, and a spoke was totally loose - I had to redistribute the tensions and it's been fine since. Whoever built that thought it was all nice and even cos it was nice and straight. But it's hard gauging tensions when spokes are all separate and not crossed, cos there's nothing to pull them against.
Anyway, on normal crossed spoking the average tension within each crossed pair has to be gauged by feel - I separate them and click them together and feel how tight they are together. Remember the gear side rear is a lot tighter than the non-gear side. You get them all nice and even, then true the rim from there, then check tensions again, if any are really badly out then re-tension, which will mess up the truing a bit, then retrue it, and eventually you get as good a compromise as possible between tensions and trueness (truth?). In theory, if the rim were unbattered, you should be able to get a perfectly straight rim and perfectly even tensions, but even a brand new rim doesn't come that good. As the guy says in that link above - "If we had a perfect wheel to work with, every nipple would be turned the same number of turns, and every spoke would be just as tight as its fellows".
If you're not sure about the centering of the rim within the frame, check for dishing. Before I got a dishing tool I used to hold a screwdriver parallel with the hub, line up the end by sight with the edge of the rim, so a line from 12 o'clock on one side of the rim would touch the end fo the screwdriver and then the same side of the rim at 6 o'clock. Then I'd use my thumb on the screwdriver shank to mark where the end of the axle was... the turn the wheel over and compare how far out the axle went. It's about as accurate as using a dishing tool but more hassle.
PS a cr@p truing stand is still better than using the bike, and doesn't cost that much.
PPS - I've edited this post to try and make it make sense.... but it still reads like gibberish. I give up! Get someone to show you in person! Honestly, truing (or even building) wheels is not a big deal, you just have to be prepared to take your time and get it right. After a few tweaks you get the knack.
PPPPPPS - and it's worth it, even before considering cost and hassle of going to the LBS. I've built way better wheels than I've ever bought, and used them over literally decades with only one or two tweaks ever to correct tiny amounts of wobble, despite some quite tough use. The very first wheel I ever built was a front M40 on Shimano dura ace large flange with rustless spokes, it took me an hour, that was in 1985 and a mate is still riding that same wheel now. The bearings are pretty shot and the rim's about to disintegrate mind you, but the wheel is still true and has never ever needed a tweak.0 -
PS - if the rim is really knackered, it might take a big imbalance of spoke tensions to get it straight - resulting in an unstable wheel that will keep going out of true. At that point, the compromise between tension and straightness becomes unworkable and you have to bite the bullet and get a new rim. I've never got to that on a wheel of my own but when I worked in a bike shop I got lads with mangled bikes trying to get me to true up wheels that were almost pretzl'd and I'd refuse cos I knew even if they ended up looking straight, they would be effectively only hanging on half their spokes, the other half being almost totally loose, to compensate for the figure-of-eight-ness of the rim.
You only mention a "slight wobble" so I assume it hasn't got to that, but if the tensions have to go wildly out and the rim won't play ball, it might be the rim is permanently re-shaped, i.e. no longer vertically flat.0
