wheel rim problems

montreal5 said:

I'm a heavy guy and my back wheel tends to go wonky pretty quickly. Two days ago, I brought my bike in for a tune-up and they trued the back wheel. I took the bike out for a 15mi jaunt and afterwards, the wheel was almost as bad as before the tune up. I went out again tonite, and after 2 mi, I looked down and saw the wheel. It was the wonkiest I have ever seen a tire. I had to take the subway home.

I'm going into the LBS in the morning, but I'd like some informed opinions beforehand. Is there anything outside of bad workmanship that could make a wheel go taco-ish. Keep in mind, I've been riding the same distance, the same router, etc without any major incident (jump, crash, etc).

Thanks

The rim is bent and/or the wheel doesn't have sufficient tension.
Weight is a major factor in how the wheel will perform. If any spoke(s) goes slack, the nipple(s) will unwind. Each time a spoke is at the bottom it reaches it's least tension. So each revolution, once the process begins, it gets worse and worse. It could be that the wheel is not stiff enough for your weight. Left side spokes on the rear wheel start off by having less tension than right rear or all front spokes. The wheel needs to be stiff enough and have sufficient tension that at no time will any spoke go to zero tension.
How much do you weigh?
What rim, and number of spokes do you have?

montreal5 said:

I'm a heavy guy and my back wheel tends to go wonky pretty quickly. Two days ago, I brought my bike in for a tune-up and they trued the back wheel. I took the bike out for a 15mi jaunt and afterwards, the wheel was almost as bad as before the tune up. I went out again tonite, and after 2 mi, I looked down and saw the wheel. It was the wonkiest I have ever seen a tire. I had to take the subway home.

I'm going into the LBS in the morning, but I'd like some informed opinions beforehand. Is there anything outside of bad workmanship that could make a wheel go taco-ish. Keep in mind, I've been riding the same distance, the same router, etc without any major incident (jump, crash, etc).

Thanks

Sometimes, a minor problem with a wheel can be aggravated over time when it is "trued" if the spokes aren't properly detensioned ...

So, presuming the rim wasn't taco'd, if the person who next works on the wheel detensions all the spokes (a potentially slow & tedious process) and basically retensions them from-scratch, it should be possible for the wheel to become sound, again.

Of course, sometimes, it only takes ~20 seconds to true a wheel ... it depends on how well it was made, originally, and why it went out of true.

Again, IMO, yet another reason for everyone to learn how to build their own wheels IF ONLY so they can do the occasional tweaking.

I weigh 230, but I've ridden at least 50 mi a week for 3 months with only a sleight wonkiness. My point is that the wheel went bonkers a day after my visit to the LBS. I have been thinking of getting a 36 spoke wheel to avoid this mess all together.

montreal5 said:

I weigh 230, but I've ridden at least 50 mi a week for 3 months with only a sleight wonkiness. My point is that the wheel went bonkers a day after my visit to the LBS. I have been thinking of getting a 36 spoke wheel to avoid this mess all together.

A well made 36 spoke wheel should handle a 230 lb. rider.
It sounds like sounds like the LBS took the tension down on some spokes. This method can give the appearance of a very true wheel, but it won't handle the dynamic loads.
I believe this is what you experienced.

montreal5 said:

I'm a heavy guy and my back wheel tends to go wonky pretty quickly. Two days ago, I brought my bike in for a tune-up and they trued the back wheel. I took the bike out for a 15mi jaunt and afterwards, the wheel was almost as bad as before the tune up. I went out again tonite, and after 2 mi, I looked down and saw the wheel. It was the wonkiest I have ever seen a tire. I had to take the subway home.

I'm going into the LBS in the morning, but I'd like some informed opinions beforehand. Is there anything outside of bad workmanship that could make a wheel go taco-ish. Keep in mind, I've been riding the same distance, the same router, etc without any major incident (jump, crash, etc).

Thanks

I agree with daveornee. I suspect that your rim is bent. If a rim isn't straight by itself, it's possible to pull it straight by tightening or loosening some spokes, but it's not possible to make a good wheel out of it. Feel the spokes that are adjacent to the direction of the wobble. If they don't feel like they're pulling the wheel out-of-line then the rim has to be bent. If that's the case you either need to have the wheel rebuilt with a new rim or buy a new factory built wheel.

In your case I think that I'd go with the latter because it will be cheaper and because I question if your bike shop has a mechanic who has the necessary experience to lace a better-than-factory wheel.