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Old 12-26-05, 04:46 PM   #1
jimmy_jazz
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"This Wheel is Untruable"

My rear wheel's been a bit out of true for a while, but when I noticed it was a bit out of round too and the wobble was a bit worse, I decided to take it in to get it fixed.
I just went to pick it up, and the work order said "This wheel is untruable, spokes are over/under tensioned. Wheel has a flat spot. Spokes Stretched."

Now, I don't know much about wheel truing, but does this sound right?
I thought the whole point was to fix any bends in the rim, tension the spokes, and then properly adjust them so the wheel is straight. Reading up a bit on the process seems to confirm this.

Can an old but not obviously damaged wheel really be a lost cause, or should I take this some place else?
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Old 12-26-05, 04:55 PM   #2
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take it to someone else
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Old 12-26-05, 05:55 PM   #3
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Quote:
Originally Posted by jimmy_jazz
Can an old but not obviously damaged wheel really be a lost cause, or should I take this some place else?
Old, cheap wheels that have seen a lot of abuse and that had improperly tensioned spoked in the first place can do that: some of the spokes stretch and progressively lose their elastic properties, you retension the wheel once or twice, and the third time, it's impossible to get the wheel trued without putting crazy tensions on some spokes, and other spokes almost slack. It also happens if the rim itself is bad (for example, rim from an "un-tacoing" job). However, a well built wheel that's not abused doesn't do that and the lacing should stay good for many years. So yes, unless you're guilty, teiaperigosa's right, take it to someone who's serious.
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Old 12-26-05, 05:55 PM   #4
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Quote:
Originally Posted by jimmy_jazz
My rear wheel's been a bit out of true for a while, but when I noticed it was a bit out of round too and the wobble was a bit worse, I decided to take it in to get it fixed.
I just went to pick it up, and the work order said "This wheel is untruable, spokes are over/under tensioned. Wheel has a flat spot. Spokes Stretched."

Now, I don't know much about wheel truing, but does this sound right?
I thought the whole point was to fix any bends in the rim, tension the spokes, and then properly adjust them so the wheel is straight. Reading up a bit on the process seems to confirm this.

Can an old but not obviously damaged wheel really be a lost cause, or should I take this some place else?
It might be bad enough that the wheel needs to be detensioned and brought back up. That's more work than just a quick tweak of lateral true. If the price quote was for the latter and if they did the former and gave you a bill for double the cost you might balk at paying.

Alternatively, it could just be that the wheel has a really bad flat spot that can't be easily fixed. See if you can get the mechanic to put it on a truing stand and show you what he's talking about. Not because you don't trust him, but so you have a better idea of what a bad wheel looks like. If you aren't comfortable with the answer, let someone else look at it.

Questions like this are one of the reasons I learned to do my own work.
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Old 12-26-05, 06:09 PM   #5
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The rim could have a flat spot where there will always be a hop. I had a pair of rims like that. They tried to take the hops out, but the flat spot was in the rim.
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Old 12-26-05, 06:17 PM   #6
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Quote:
Originally Posted by jimmy_jazz
Now, I don't know much about wheel truing, but does this sound right?
Can an old but not obviously damaged wheel really be a lost cause, or should I take this some place else?
To me it sounds logical. What they are saying is possible. I can't say if it's the truth with your wheel but if a rim has a flat spot it might be beyond the ability of the spokes to take care of the problem. You can't fix a "bend" in a rim by manipulating the spokes. You say it is not obviously damaged so I won't say that the shop is absolutely right. You might have to take it to someone to look at so that you feel comfortable with the diagnoses. If they say the same thing then it is probably correct. Hopefully you won't have to keep paying to have it looked at.
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Old 12-26-05, 06:33 PM   #7
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A new rim will be nice and round and very flat when laid on it's side. When such a rim is laced onto a hub, all of the spokes will have nearly equal tension.

If a rim has been significantly bent for any reason. Pulling it into line by merely fiddling with the spokes will result in very tight spokes on one side and little or no tension on the other. It might be possible to ride such a wheel for a time, but it's definitely going to fail at some point.

Sometimes it's possible to rebend a warped rim back into line and retension the wheel. In most cases, however, that's reserved as an emergency measure. Generally the labor involved is at least as much as completely building a new wheel so it usually makes more sense to start over with a brand new rim. I'd personally not want to let a wheel that I didn't feel I could warantee go out of my shop.
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Old 12-26-05, 06:35 PM   #8
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Quote:
Originally Posted by ppc
...some of the spokes stretch and progressively lose their elastic properties...
I don't think so.
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Old 12-26-05, 07:06 PM   #9
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Thanks for all the input.
I was mostly suspicious because I took it to Performance, and I don't know anything about the quality of their work. At least they didn't charge me since they couldn't fix it.

When classes are back in session, I'll take it to my "LBS" (which is local to my campus, but not my home, which is why I didn't go there in the first place). At least then if they say it's not fixable, I'll be more comfortable with that diagnosis, and can get them to show me why.

I'm not the bike's original owner, so I can't vouch for it's history of abuse, but it certainly hasn't seen any unusual shocks since I've had it.

Mostly I'm just concerned since, post X-Mas, I really don't have the funds to buy/build a new wheel.
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Old 12-26-05, 07:24 PM   #10
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Quote:
...some of the spokes stretch and progressively lose their elastic properties...
No, this doesn't and can't happen. Spokes can be deformed by mechanical damage but they don't "progressively" stretch or "lose their elastic properties". This is the same myth tht says frames get "soft" after miles or years of use. It doesn't happen.
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Old 12-26-05, 07:35 PM   #11
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Not that this necessarily applies to your wheel, but I used to get wheels in the shop like that. A lot of times "untruable" meant "we can true it but we aren't comfortable standing behind the work". That used to happen all the time. Once we trued a wheel, the customer expected it to stay true, and if it didn't we were on the hook to redo the work for free. If we told them it was untruable we'd sometimes get accused of just trying to sell them a wheel.

Some of us tried telling the customer "we can do it, but we can't guarantee it will stay true" but they still came back to complain...plus there's a liability issue if the person crashes. Whether it was due to that wheel or not, we would still be named in a suit. Therefore "Sorry, this wheel is untruable" became what we were forced to say. Sad, but that's the world we live in.


Anyway, I had an "untruable" wheel recently that I trued anyway and was running on the back of my Xtracycle. I ran into a friend and told him to hop on the back. He weighs about 140Lbs. We got about 10 feet and the wheel exploded, the back end dropped so far and so fast that my nice old Suntour XCPro rear derailleur exploded too, and the chain snapped. Had that wheel been able to have proper tension that probably would not have happened. So now I'm building the XCPro hub up on a Syncros BigBox rim I have, and I'll keep it around as a spare.
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Old 12-27-05, 06:36 AM   #12
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Quote:
Originally Posted by ctp
Not that this necessarily applies to your wheel, but I used to get wheels in the shop like that. A lot of times "untruable" meant "we can true it but we aren't comfortable standing behind the work". That used to happen all the time. Once we trued a wheel, the customer expected it to stay true, and if it didn't we were on the hook to redo the work for free.
Exactly! There are things that I might tolerate on my own bike that I wouldn't do on a customer's bike. It's easier to explain to a customer why a repair was costly than it is to explain why it didn't stay fixed.
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Old 12-27-05, 06:51 AM   #13
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If you run out of available thread on some of your spokes for the spoke nipples to tension or if the rim eyelets are cracked or pulled out or the nipples and rim corroded such that they turn only with great difficulty, then it may be impossible to tension the spokes enough to do a quality job.

Ultimately the value of the labor time required to true the wheel may exceed the cost of a replacement wheel. While that may not render the wheel untruable, unless the wheel has a vintage or collectible value, it effectively means the same thing, although they should just say so.

Most shops have an expected allotment of time for a truing, as with any fixed-charge service. Exceeding that while being unable to expect durability of their work
only compromises their reputation while losing them money. Not a good idea.
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Old 12-27-05, 10:52 AM   #14
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Originally Posted by CHenry
if the rim eyelets are cracked or pulled out
... then the tim is trash. Reccomend a new rim, don't just say you can't true it.
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Old 12-27-05, 12:16 PM   #15
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To some degree, this is a safety issue. I'd be careful from where I accept advice.
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Old 12-27-05, 12:17 PM   #16
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Originally Posted by Primo Tiki
... then the tim is trash. Reccomend a new rim, don't just say you can't true it.
(Again, I can only speak for the shops I've worked for...)

For good wheels that's exactly what we would do. Also, a customer who rides on good wheels is likely to understand our diagnosis and explanation. But most of the messed up wheels we would see in a day retailed for less than _just the labor_ to relace, tension, and true. So you recommend a new wheel. Maybe the customer decides to go to another store. If you are lucky the next shop will tell them the same thing - although they may decide to just get the wheel from them since they are already there. But there's a chance the next shop will try to fix it and take their money. If you are lucky there, the wheel will flake out and they will come back to you now trusting your word. Or they could get it fixed, ride it 10 miles just fine, and hang it back up in the garage for the next 5 years where it was hanging for the past 5 years before they brought it to you...in that case you just lost a customer for telling the truth. Did you want that customer anyway? No, but even more importantly you didn't want them trashing your name to potential customers.

It's a tricky game. With most of the people buying bikes from big box stores, and having no idea why any bike should cost more than $175, it's an uphill battle that none of the shops I ever worked for could fix on their own. The NBDA tries what it can, but in a car culture only so much can be done. Someday I'll tell you all about living in Amsterdam...bike heaven.
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Old 12-27-05, 12:43 PM   #17
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Quote:
Originally Posted by HillRider
No, this doesn't and can't happen. Spokes can be deformed by mechanical damage but they don't "progressively" stretch or "lose their elastic properties".
Please re-read my post: "Old, cheap wheels that have seen a lot of abuse and that had improperly tensioned spokes in the first place".


Quote:
This is the same myth tht says frames get "soft" after miles or years of use. It doesn't happen.
Agreed for a frame, there's just too much metal for any of it to leave the elastic domain. But take a thin steel wire like a spoke and overload it, and the metal will reach the yield point sooner or later.
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Old 12-27-05, 12:57 PM   #18
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Originally Posted by ctp
omeday I'll tell you all about living in Amsterdam...bike heaven.
I wonder about one thing from Amsterdam... I have heard that there are laws on the books there and in the EU in general that make for large fines or punishments if a motorist hits a cyclist. Is that true? Can you confirm that in any way?
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Old 12-27-05, 01:36 PM   #19
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I wonder about one thing from Amsterdam... I have heard that there are laws on the books there and in the EU in general that make for large fines or punishments if a motorist hits a cyclist. Is that true? Can you confirm that in any way?
I can't confirm that, but I will do some digging. The EU did not exist when I lived there, btw.

What I can say is that when I was in London it was very much like here. Cyclists were an expendable nuisance to motorists. If they got hit it was tough luck - "they shouldn't have been on a bike, they knew the risks!". On the continent however, cyclists were often equal to, or even elevated above the status of the car. This depended a lot on the locale, but in northern Europe this was certainly the case. I rode on wide bike specific roads, that were safely separated from auto traffic, that had their own bike specific traffic lights, and they went everywhere. In town it was a true "critical mass" of bikes (in the original George Bliss sense of the term) that found safety in numbers, and more respect from motorists than I ever found here. http://www.6URL.com/0AIE

I remember walking into a hardware store in Amsterdam, and found a section of bike stuff. Not like one finds in OSH or Wal-Mart. This bike section had bins of brake calipers, and brooks saddles, and cables and housing, and racks, and pumps, and what-have-you. Not all blister packed, not behind the counter...BINS FULL!!! I met 6 year olds who could already rebuild a hub, or change a brake cable. (cue heavy sigh)

Okay, now see what you've done? I'm ever further off topic than I usually am.
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