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So I broke a spoke a week ago, and when I put a new spoke in you know I trued it. Now, a week later, the bike feels like a kayak, because the back wheel is not very straight. Any idea why this would happen?

Some other information:

  1. Hybrid road/mountain bike, single speed. Pretty tall, like a 62cm frame I think, with relatively small wheels.
  2. I rode the bike with a broken spoke for another 30 miles or so before I had a chance to do something about it.
  3. I wheel got so out of whack with my broken spoke that it caused trouble with the rear brake: if I jammed the rear brake, the brake pad would slip off the wheel.
  4. Everything was fine up until the past few days

It's still rideable, and when I have a moment I'm going to go to the shop and true it again (hey, bikerowave!), but it seems like a waste of time to do that if there's some essential problem I'm ignoring.

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How much had the bike been ridden with the broken spoke, and did you true it that way too? When you tured the wheel, what exactly did you do? Your description makes me doubt you used a spoke tensiometer, is that correct? –  Мסž Jun 22 '11 at 21:48
    
I road on it the distance to get home, get where I needed to be the next day, and then to the bike place. Probably like 20-30 miles. And what makes you doubt that I used a tensiometer? I did! I set it on one of those bad boys that clamps your wheel and place and then you spin it and see where it hits the little claw bit on the front, and you have to check the tension on like every one of those guys, and then you do the clampy bit (ie the tensiometer) to see how that spoke is doing. Then you get all his buddies in line, pull the claw in a bit, and do it some more. –  JKDDOW Jun 24 '11 at 4:55
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3 Answers

I strongly suspect your spoke tension is quite uneven. If you installed the new spoke by just adding the new spoke, then that's even more likely.

A wheel with uneven tension will do exactly what you describe. There should be only two different spoke tensions in a rear wheel - the tight side and the loose side. Wheelbuilders will keep working a wheel until they get +/- 10% or so. Smaller range on a new wheel, wider on a cheap and/or old one (wheelbuilders rarely build cheap new wheels, those are made by machines). If you don't have a tensiometer (Park tool one, ~$60) you can possibly do it by the pitch of the spokes but I've had little luck with this - it's more affected by where the spokes cross each other than by spoke tension (ymmv, I have perfect pitch and am in other ways fussy, plus I have access to a tensiometer).

The problem with older wheels is often just getting the nipples to move on the spokes. That can take lube and time. Often more time than the cost of a new wheel. But if it's your time, that's "free". Again, use a grease-based chain lube (or for once, WD-40 or similar) on the spoke/nipple junction and also the rim/nipple area. Then work each spoke gently (less than half a turn) until the spoke moves on the nipple. Realistically, gently is an exaggeration - you don't have a lot to lose by breaking the spoke doing this, except that breakage normally happens on marginal wheels (cheap and broken), so you run the risk of breaking enough to make the wheel uneconomic to repair even if you're only paying for new spokes not labour.

I think your best bet now is to make sure as many nipples are free as possible, then take it to a bike shop. It'll cost $30-$100 to fix, but most shops will let you say "spend $X on it, then call me".

At some point the wheel is so warped and unreliable that you just need to buy a new one. I think you're 90% there right now. It depends on how much you're a gambler... you might spend $30 and get the wheel nicely trued and solve your problem. Or you might spend (say) $50, get the call and they say "it's definitely broken now" and you have to buy a new wheel.

If you're short on money another second hand wheel might work, and it'll definitely be cheaper than a new one. Check your local tip shop/ bicycle recycler for cheap ones.

edit: tensiometers are standard bike shop tools, the cheap Park ones work pretty well and are only about $US60 online. The more expensive ones don't work a huge amount better but cost a lot more ($US300+). I've compared a DT Swiss micrometer-based tool to a Park one and no-one in the shop could reliably measure more accurately with the DT one. It was harder to use and heavier so we went back to the cheap one. Park tools spoke tensiometer

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That's good advice, but I didn't spend $30-$100 for the spoke + truing the first time, so I don't think I'm going to spend $50 on a new wheel. –  JKDDOW Jun 24 '11 at 3:23
    
@JKDDOW: I didn't suggest that, I'm trying to suggest ways to fix it and make it explicit what the tradeoffs are. I agree that you shouldn't spend $50 on a new wheel - if you're going to buy a new one, buy a decent one. –  Мסž Jun 24 '11 at 4:12
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A new spoke will stretch when newly installed in a wheel. This is expected. If you still experience the wheel going out of true after a week or two, there may be something else going on.

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Bed in might be more accurate than stretch. The new spoke will settle into the hub and the bend at the head might give a bit. –  Andy Morris Jun 23 '11 at 10:22
    
It is also unlikely to bed in quite so much as to matter. I would definitely look to damage to the rim on a wheel with that history. Occam's Razor... –  zenbike Jun 23 '11 at 14:35
    
@zenbike: spokes can bed in quite a lot, enough to make rim brake adjustment tricky, especially on a second hand wheel. But agreed, not as much as this one has. –  Мסž Jun 24 '11 at 4:14
    
@stevie_boy_up_there yeah, that seems pretty good. I think imma jerry rig the spokes right (I don't have a nipple wrench here) till I get to the Bikerowave to work this out proper with the tensiometer and what. Thanks, guy! –  JKDDOW Jun 24 '11 at 4:59
    
@Moz, yes they can. I wasn't trying to imply they wouldn't bed in, or that a wheel wouldn't be affected, even severely, by it. Only that in the case of a wheel with known damage, that isn't where I would look first. –  zenbike Jun 25 '11 at 7:37
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Your wheel may have really uneven tension on the spokes. The rear wheel is "dished" so the spokes on the side with the freewheel/cassette will be shorter/tighter/more vertical. If you notice spokes on the same side having more tension than others, that may be part of the problem. A shop will have a tension gauge to help diagnose the potential issue too...

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