Bicycle Mechanics - Wheel misery

My rear wheel is giving me fits. Sometimes it'll stay true for weeks, and then it starts getting the wobbly. After truing, it may stay true for quite a while or it may go out in just a few miles. I was truing it myself, so I decided to give the pros a try. I took it to my LBS Monday and a guy that's worked there 19 years trued it for me.

Within 10 miles it was out again. Several of the spokes were noticeable loose. I tightened them up and retrued the wheel and it stayed for the rest of my 30 mile ride.

But this is getting annoying. Is it the wheel? (It's a Matrix BTW, and it's only the rear wheel, the front is fine) Is it worn out and simply time for a new one? Why would the spokes loosen up after 10 miles? Could the spokes be worn out? I just bought the bike a couple months ago from a guy that never rode it. It's a 1998 Trek 2120, so it's been sitting quite a while.

TIA!

Az

Yup. That would be annoying alright. Here's what I would do before giving up on it if it were my wheel:

1. The first thing that I would do would be to carefully examine the rim. I'd look for spider web cracks around the spoke holes and I'd check for loose spokes wherever there's a wobble in the rim. There's no point in fighting with an iffy rim.

2. Then, I'd make sure the tension was snug and even on all of the spokes using my tensiometer. If you don't have one and you're musically inclined you can try the spoke plucking method, but it's important to start with them all even.

3. After you do that, you're going to have to retrue it. It sounds to me like you've done this before. The only trick is to work with opposing pairs of spokes and to tighten one and loosen the other the same amount.

4. Lastly, I'd put a tiny drop of post tightening loctite on each nipple. That's not something that I normally do but I'd make an exception in your case.

AZ B,

This has been happening to me recently and it is annoying! Anyway, while I was at local Performance Bike yesterday to by a Joe Blow floor pump (50% off) I asked the head wrench about this phenominum and he pretty much told me what Retro indicated. Only difference is he offered 'true and lock' the nipples for me. I took my wheel to him during lunch and he fixed'er up. I need to put some mile on it to be sure it is the right answer.

FWIW the wheel I am having this problem with is a Mavic Open Pro I ordered online from Supergo. I have heard this is a common problem with machine built wheels .... I don't know if this is true or not.

Good Luck

My rear wheel is giving me fits. Sometimes it'll stay true for weeks, and then it starts getting the wobbly. After truing, it may stay true for quite a while or it may go out in just a few miles. I was truing it myself, so I decided to give the pros a try. I took it to my LBS Monday and a guy that's worked there 19 years trued it for me.

Within 10 miles it was out again. Several of the spokes were noticeable loose. I tightened them up and retrued the wheel and it stayed for the rest of my 30 mile ride.

But this is getting annoying. Is it the wheel? (It's a Matrix BTW, and it's only the rear wheel, the front is fine) Is it worn out and simply time for a new one? Why would the spokes loosen up after 10 miles? Could the spokes be worn out? I just bought the bike a couple months ago from a guy that never rode it. It's a 1998 Trek 2120, so it's been sitting quite a while.

TIA!

Az

Been there, done that and it sure is frustrating! Most likely spoke tension is the culprit. Simply getting the wheel true is only half of the equation. This is even more applicable to low spoke count wheels since each individual spoke carries a greater percentage of the total load.

I agree with Retro. Even spoke tension between spokes is critical. Overall tension of the wheel is critical too. The only measurable way of checking both is with a tension meter. Take the wheel to a shop that knows how to use one. The post build thread lock is probably a good idea on this wheel too.