Road Cycling - How much does it take to make a wheel out of true?

Hi,
I'd like to know how much force it takes to bring a wheel out of true. I have not had my bike long and I think that it might already be. I'd just like a general idea for my own personal reference. (Bike is going today to the LBS for its one month tune up)

:beer: S

This is one of those things that doesn't really have an answer because there are many variables involved. I have had wheels that were so tight and true even a broken spoke did not affect the trueness very much. On the other hand a wheel on a new bike can go out of true for a number of reasons.
1. The machine built wheel is true but not at tight as it should be.

2. Riding causes the spokes to "settle in", assuming a new position and forming a little depression where they contact the flange exiting the hole.

3. Flexing due to lack of pre-stressing.

Same with new brake and shift cables. They don't actually "stretch" though that term is applied, but they do settle in with curves and bends pulling tighter and sharper, resulting in slack that needs to be taken out.

A well tensioned wheel will take quite a bit of abuse before going out of true. A loosely tensioned wheel will go out of true almost immediately.

Does that sufficiently muddy the waters? :D
Raymond

Originally posted by Spire
Hi,
I'd like to know how much force it takes to bring a wheel out of true. I have not had my bike long and I think that it might already be.


True is true.

If you can see wobble with the naked eye, it's not true. If you spin the wheel and lightly, partially close the brake and the rim skims a brake pad at just one place, it's not true.

It's also possible for a wheel to be out of round, which you can see by visually lining up a brake pad with the rim while spinning the wheel.

It is very common for machine-built wheels to go out of true if they weren't properly prepared before you started riding on them. It's not a matter of "force." An improperly tensioned wheel can go out of true just from being ridden.

A good shop should take each new wheel, stress-relieve the spokes, and retension and true the wheel with a tensionometer before delivering the bike to the customer. Unfortunately, this is too often not done.

Worse than going out of true, lack of stress-relieving can lead to broken spokes, something that rarely happens at all on a well prepared wheel.

I would ask at the shop what was done to prepare your wheels.

RichC

Thanks for the information. I will ask. Should I ask for something special (like stress relieving the spokes or some such?) when I take it in for the one-month tune up this afternoon?

:beer:

Stress relieving is done during the building/truing process. It's not something you order as a special service.

You could ask a question like: I've heard that wheels are supposed to be stress relieved; what does that mean? Or some such non-offesive type question. Most mechanics are eager to show you their knowledge IF they don't think you're being antagonistic. Good Luck.

Conversely, if they say something like; ahhh, that's not important. we don't fool with it. Then you need to find another mechanic.

Originally posted by Spire
Thanks for the information. I will ask. Should I ask for something special (like stress relieving the spokes or some such?) when I take it in for the one-month tune up this afternoon?


I don't know that I've ever heard that stress-relieving spokes that have already been ridden a lot does any good, or that it wouldn't cause more problems.

Stress-relieving is done after tensioning the spokes on a new wheel, to help "unwind" them and seat them in the nipples and hub. It's often not done on machine-built wheels, because it's usually necessary to tweak the tensioning and truing after stress-relief. That's why it should be done on new wheels by the bike shop.

But it's always good to know as much as there is to know about your wheels. And if they're out of true, then truing them and correcting the tension should certainly be part of your tune-up.

RichC

Originally posted by Rich Clark



Stress-relieving is done after tensioning the spokes on a new wheel, to help "unwind" them and seat them in the nipples and hub. It's often not done on machine-built wheels, because it's usually necessary to tweak the tensioning and truing after stress-relief. That's why it should be done on new wheels by the bike shop.

RichC

Mind if I disagree with you? Stress relieving is done during the ENTIRE tensioning process, not just at the end. And that also goes for retruing a wheel. The spokes twist during retruing just as they do in the original build and need to be stress relieved if you are going to get a properly tensioned wheel that will last for more than a ride or two.

Originally posted by ljbike
[B
Mind if I disagree with you? Stress relieving is done during the ENTIRE tensioning process, not just at the end. And that also goes for retruing a wheel. The spokes twist during retruing just as they do in the original build and need to be stress relieved if you are going to get a properly tensioned wheel that will last for more than a ride or two. [/B]

I don't think we disagree. You just said it better. :)

As for stress-relieving when retruing, yes again... except I wonder about what happens over several hundred miles to a new wheel that was never stress-relieved, and whether stress-relieving it after that could cause additional problems.

RichC

In my limited experience it can only be beneficial. This said after truing several hundred (?) wheels. Those I've trued seem to stay that way longer, but you must remember, my point of view may be prejudiced.

Getting back to the original question, Raymond said it; The ability of a wheel to stay true depends very much on the wheel.

I have seen some wheels take some terrible abuse and still stay true while others are just a pain in the fanny-wanny and won't stay true no matter how good you are to them.

Spire, check out this site. You'll learn more about "stress-relieving" than you want to from Jobst Brandt.
http://draco.acs.uci.edu/rbfaq/FAQ/8c.1.html
:beer: