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Old 09-11-11, 04:59 PM   #1
davehbuffalo
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Wheel maintenance and Spoke Tension - Leave well enough alone?

I've done some searching and reading about spoke tension, and I think maybe I need some maintenance on my rear wheel.

According to what I've read, spokes on a front wheel should have roughly the same tension on both sides, spokes on the drive side of the rear wheel should have roughly the same tension, and spokes on the non-drive side should have roughly the same tension, but not necessarily the same as the drive side.

"Roughly" means that due to imperfections in rims and spokes, variance in tension is required to get the rim true. So far so good?

I recently had some wheels built -- 36 spoke Salsa Delgado, Shimano 105, DT Comp Butted. Sure enough, front spokes seem roughly the same tension, drive side roughly the same, non-drive side has less tension, but also has a lot of variance and some spokes seem ridiculously loose.

The wheels are professionally built and straight and true so part of me says I shouldn't mess with them, but on the other hand, the spokes that seem loose seem like they could be tightened a bit with no ill-effect because they're not doing much now anyway (?).

Would I be foolish to carefully put some tension on the loose spokes, or is this just part of sound maintenance? If I did it, I would do so slowly, carefully, a little at a time while checking both round and true.

Or... do I leave well enough alone? Taking to a shop at this point really isn't an appealing option because at some point I have to learn to do this myself.
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Old 09-11-11, 05:15 PM   #2
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Not seeing the wheel it's hard to advise, but here's some hints that might help you decide whether you should leave well enough alone.

On rear wheels the left spokes will average roughly 60% of the tension of the right. Any increase in average tension on the left, without changing the right will pull the rim to the left.

Also understand that adjusting the right side will tend to have greater radial effects than the left, and the left will tend to affect wobble more. That means that even minor changes in left side tension will tend to pull the rim to the left and require significant compensating adjustment of the right spokes, possibly pulling a hop into the wheel.

As you can see, it can be very easy to introduce uneven tension on an otherwise good wheel. I always operate under the rule that if it ain't broke, don't fix it. But if you decide to go ahead, go slowly, take up slack, but if the rim responds by moving left, back off until it's back where it started.

I understand you want to get started learning, but in your shoes, I'd enjoy the wheel as it is for as long as possible, and start learning when it needs service.
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Old 09-11-11, 05:16 PM   #3
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loose spoke paired next to a really tight spoke? if yes then you need some tension balance
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Old 09-11-11, 06:07 PM   #4
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Originally Posted by FBinNY View Post
Not seeing the wheel it's hard to advise, but here's some hints that might help you decide whether you should leave well enough alone.

On rear wheels the left spokes will average roughly 60% of the tension of the right. Any increase in average tension on the left, without changing the right will pull the rim to the left.

Also understand that adjusting the right side will tend to have greater radial effects than the left, and the left will tend to affect wobble more. That means that even minor changes in left side tension will tend to pull the rim to the left and require significant compensating adjustment of the right spokes, possibly pulling a hop into the wheel.

As you can see, it can be very easy to introduce uneven tension on an otherwise good wheel. I always operate under the rule that if it ain't broke, don't fix it. But if you decide to go ahead, go slowly, take up slack, but if the rim responds by moving left, back off until it's back where it started.

I understand you want to get started learning, but in your shoes, I'd enjoy the wheel as it is for as long as possible, and start learning when it needs service.
Thanks for the detailed answer -- clears a few things up. I haven't decided completely against a little adjustment (per the bold) but I have decided not to worry so much about it and keep a careful eye on things.
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Old 09-11-11, 06:19 PM   #5
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It's the loose spokes that will break due to excess flexure. Random loose spokes mean a bent rim or very poor wheel build.
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Old 09-11-11, 06:28 PM   #6
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Agreed with last poster. I don't think you should ever have spokes as loose as the ones you appear to be describing. I once bought a bike to flip that had a seriously out of true rear wheel. Turns out the rim myself had somehow been bent. I was able to mostly true the wheel but to compensate for the bend there were some spokes that ended up being really tight and others super loose. Im no expert on wheel truing, but it sounds like a poorly built wheel or one that is damaged. Who built it for you? Did they use new or used parts?
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Old 09-12-11, 08:24 AM   #7
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Have you considered speaking to the builder? Can he or she confirm that they tensioned the wheels? Asz previosly posted, a slack spoke (or two) right next to much tighter spokes could mean that a slightly bent rim was used in the build or simply that tension is not evenly balanced where it could be wich will increase the life of the build. If these were my freshly built wheels, I would ask the builder to confirm this. If you start working on the wheels yourself, you will eliminate any waranty you may have been provided with.
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Old 09-12-11, 09:19 AM   #8
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How are you determining spoke tension?
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Old 09-12-11, 09:21 AM   #9
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You can roughly test them by plucking them and listening to the tone. A well-built and tensioned wheel will have no more then a fifth tone variation between spokes on the same side of the wheel- basically two keys worth on the piano. It's a square-law from tones to tension- an octave (2x the frequency) is 4x the tension. Typically it's better than that- one note on the piano. Any good handbuilder will be able to do this.
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Old 09-12-11, 10:34 AM   #10
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If you're having misgivings about the the build quality of your custom wheels, you should talk to the builder about it.
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Old 09-12-11, 10:49 AM   #11
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no more then a fifth tone variation between spokes on the same side of the wheel- basically two keys worth on the piano.
How the heck do 2 neighbor notes on a piano make a 5th?!!! That should be a minor or major 2nd.


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It's a square-law from tones to tension- an octave (2x the frequency) is 4x the tension. Typically it's better than that- one note on the piano. Any good handbuilder will be able to do this.
Now that is interesting to know. Thanks!
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Old 09-12-11, 11:13 AM   #12
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Re tensioning spokes is common maintenance..

if the builder used Wheelsmith spoke prep on the threads, once cured,
It has some threadlock like function.

Using Anti-seize instead lets one re-tension the spokes as a normal wear and tear of use requires.

I suspect the spoke wound up when the wheel was built,
then the torque build up relaxed , unwinding at the nipple.

Last edited by fietsbob; 09-12-11 at 11:17 AM.
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