Getting wheels trued...
 

I bought a set of 2009 Ksyrium Elite wheels over the summer and unfortunately hit a pothole after only owning them for less than a month (had my head down hammering looked up at the last second). The rear wheel got knocked out of true, but I kept riding it until a few months ago. I brought it to an LBS (relatively new, but a local branch of a reputable shop ~1 hr from my house) and the guy trued it up pretty good. He said there was a "hop" in the wheel because of the pothole, but that it wasn't awful. After getting it trued, the wheels rolled fine and I couldn't even feel the hop.


Fast forward to last week. I hopped on my bike late for a ride and rolled out of the garage. As I rolled out of my garage (there is a lip between my garage floor and my driveaway, about 0.5-1 inch) I noticed a loud clunk. Turns out I had a flat tire. Well that even seems to have knocked my rear wheel out of true again and I can feel a noticeable "bump" in the wheel when riding.

So, should I bring it back to get retrued again? Should it go out of true rolling off a 0.5" lip on a flat tire (admittedly a stupid thing that shouldn't happen again) or was the last time it got trued not done "correctly." These damn wheels are supposed to be bombproof so idk wtf is going on. I weight 125 lbs, these wheels should be more than capable of handling my weight...

Your wheel wasn't knocked out of true by the lip going out of your garage. The likely cause is that the mechanic merely trued the wheel without bothering to check spoke tensions. Uneven tension will yield a wheel that can go out of true very easily, including from the forces requires to dismount and remount a tire. Or, it could have been that way for a while and you just now noticed it. I'd suggest finding a mechanic with a spoke tension meter and let him thoroughly go over the wheel. Keep in mind that if the rim was damaged, he'll have to balance between even tension and trueness. A wheel with even tension yet not perfectly true will be stronger than a perfectly true wheel with uneven tension. You may have to settle for a slightly untrue wheel in your case.

Sounds more like a tire seating issue to me at this point......

0.5"?

That is a LOT. Also can we be reassured that the bump isn't caused by an improperly repaired flat with the valve pulled through?

I believe he used a tension meter. I could be mistaken, but it looked as if he was using one to check the spokes. However, he trued the wheel in like 15 minutes. How long would it take to properly check the tension on each spoke?

I can see the wheel wobble when I spin it and look at it. I did the whole fill the tire w/ air then let all the air out then fill it out again in order to get the tire/tube seated. Any other tips?

15 minutes is plenty of time for a minor wheel truing. That he used a tension meter is no guarantee that he evened out the tension though.

The tube that is in there is a new tube. I am confused as to what you mean by improperly repaired flat...

I just measured the drop and it is actually 1.5 inches. I know it is a sizable drop, but not huge. Nothing extraordinary compared to some of the pot holes around here.

most mechanics don't check every spoke for tension. a really good mechanic won't even use a tension meter, they will know just by feel. they might check a few opposing spokes more for reference. its true that a spokes with the right tension is important but they don't have to exactly the same. its important to balance between the correct trueness and spoke tension.

A wheel trued with a tension meter will have more even tension than one without regardless of the skill of the mechanic. This becomes more important as the spoke count of the wheel gets reduced.

2009 Ksysriums shouldnt need to be trued this soon. I hope youre not paying for any of this...

You can't just inflate and deflate the tire and hope that it's correctly installed. You have to check. Check that the bead is seated the same all the way around. Most tires have a molded-in line near the bead that you can use to check. Just look around the tire and see if it's a consistent distance from the rim. Check both sides. If there's a low spot where the tire is too far in the rim, squeeze the beads together around the rest of the tire and pull the low spot outwards. If there's a high spot check that the tube isn't pinched between the tire and rim (see next paragraph) and pull the tire out around the rest of the wheel.

You also need to check to make sure that the tube isn't pinched under the bead. You do that by deflating the tire, and starting at the valve, pull the tire to one side and look between the tire and rim. If you see tube or don't see rim strip something is wrong. Work your way around the tire checking both sides I do this before inflating. It only takes 30 seconds.

As far as the rim goes, rolling off a 1.5 in drop probably didn't cause it to go out of true. Wheels tend to go out of true easier once they have been out of true. And rims that are out enough to require significant compensation in spoke tension also tend to go out of true easier because of the uneven spoke tension. It's probably been going out of true for a while.

If there's a hop in your rim then it's likely some spokes in that vicinity are at less than optimal tensions. This will cause the wheel to go out of true easier. I'd raise overall tension of the spokes a little bit and keep riding until a new rim is absolutely necessary.

You've received plenty of good advice about your wheels already. I'm going to advise you to always give your bike a quick going over before hopping on it to go for a ride. At the very least, give your tires a quick squeeze to check for air pressure. I always top 'em off before a ride, takes very little time and I haven't had a pinch flat in two years.

Yea I've learned that now...


So, should I bring it back to the same LBS to get retrued (only about $15, not a huge deal)? Or is that basically useless at this point?

Does the hop go towards the hub or towards the tire?

If the hop goes towards the hub, the rim is bent ("flat spot"). If the rim is flat-spotted, you can't apply "negative tension" to the spokes to pull it out. (It is possible to try and whack the rim to bend it back out, but I've never had much success with that technique...) Once a rim is flat-spotted, it's done. Ride it, slam it into everything, and when it finally fails to clear the frame/fork, get a new rim. It's hard to damage anything else on the wheels unless your spokes are so loose in the flat spot area that the spoke nipples unscrew completely from the spoke.

If the hop goes out towards the tire, the spokes are not tensioned enough (or, hopefully, are not tensioned enough). You should be able to use spoke tension to pull the rim in towards the tire. Typically this happens near the seam on relatively new wheels. I would bet this is not the case.

Once a rim is bent, I'd write it off. I wouldn't bother paying anyone to true it. Ride it till you can't stand it and then get a new rim laced onto the wheel.

FYI I watched mechanics true wheels after a stage in the Tour Du Pont (granted it was a while ago, but they had aluminum rims...) The guys on the big money team, Gatorade, were riding the most insanely bent up wheels imaginable. I'd have trashed all of the wheels, but the mechanics were gamely cranking away at the wheels. They were truing wheels to clear the frame, not to make things "straight/round". They'd look at reasonably large gashes in the tire and squirt Super Glue into the cuts. Even Lemond (I also watched the Z team) wasn't immune to this - I figured a guy like him would warrant new tires regularly. But his Z team did the same thing - Super Glue into the cuts on his tire. So true wheels are not critical, just nice to have.

cdr

I am not sure in which direction the hop is in. It is from hitting a pothole, so I would assume a flatspot. That being said, when the wheels were true, I couldn't feel the hop so I assume the hop is not the issue more that the wheel has gone out of true again. I am not really overly concerned about having perfectly true rims, but I want to pick up some Mr. Crud fenders and I am worried about them dragging if my rim has a slight wobble in it...

Alright....so I took a look at the wheel and it turns out that it was not 100% seated correctly. There was a bulge around the valve stem. I deflated the tire and worked the tube so that the bulge is now no longer there and voila! The wheel spins straight and true. I am an idiot.

...well....at least you feel you've identified the root cause. ;)

Words of advice - because this is probably the most interesting thread around right now *sigh*....

Best thing you could ever do is check your pressure before every ride. You will catch problems before they become issues and you will greatly reduce the number of flats you will end up with.

When you get a flat do some diagnosis to determine the cause. There's only a few ways a tube will flat. They all have telltale marks or ways of identifying the cause. Learn the ways to identify them - I have it all somewhere in my tip of the day thread...http://www.bikeforums.net/showthread...tip-of-the-Day

Don't replace a tube until you are reasonably sure you have identified the cause of the flat and eliminated any remaining hazards - replaced rim strip/covered spoke head, removed debris, etc...

If you had done these things the thread wouldn't have occured....so I guess I'm torn....