Tire closer to one side of frame?

So I just mounted my new 24"x2.75" knobby tire on my nimbus, and I noticed that the top of the tire in the frame is closer to one arm of the frame than the other through the entire rotation. Is this a problem with the hub being off center, if that’s possible, or is my wheel leaning? I didn’t notice until I put the wider tire on because it gets closer to the frame than the 2.125". I do feel like the uni always wants to go off course to the right all the time, requiring constant correction to keep going straight.

Thanks,
Chris

It is most likely a dishing error. Take it to your LBS and they should be able to correct the dishing pretty easily. On rare occasions it can be a frame and/or bearing holder asymmetry, but much more likely it’s the dishing. And the leaning/pulling thing (when riding on level ground) is a common result of an off-center, misaligned wheel, and not the rider!

you can try tightening spokes on the far side and loosening them on the close side.

+1, maybe the wheel is just off center. On my trials uni the wheel is jsut way too off center so I put a few pieces of paper in my bearing holder to get it centered… I’m just too lazy to get it centered because it’s all dying anyway.

But, you should take your wheel off and see if there’s anything in your bearing holders that makes the wheel off center and if there’s nothing do what “unireed” told you.

take the frame off, and turn it around. if it’s still close on the same side, then it’s a wheel dishing problem. if it switched to the other side, one side of the frame is different than the other, and you’ll need to shim it. i just cut lil stips from an aluminum can and put em there. 1 is all you need…2 at most.

Yep, either the wheel is dished as terry said or the frame is slightly longer on one side than the other.

Strike that, Reverse it.

If the wheel dish is off the rim will change from one side to the other when you turn it around. If the frame is off the wheel will stay close on the same side regardless of which way it’s in the frame.

Thanks! I’ll take a look later today. If it is the dish but I correct it with a shim, is there anything bad that will happen? To correct dish, do I just loosen the close side starting at valve and going around all the way then tighten the otherside same way? My guess is a 1/4 turn per spoke per trip around the wheel. It was just trued so I’m hoping not to mess it up again.

Was it trued by a professional? If so, the dish should be dead center, and you have a different problem. If it was trued by a pro, and the dish isn’t right you should bring it back and have them re-do it. Dishing and truing go hand in hand you don’t do one without the other.

It was trued by a colleague who is a big road cyclist that has a truing stand. I’m not sure of how exact he is on all the aspects of truing/dish etc. He did make sure the rim was straight and that all the spokes have even tension. Beyond that, not sure.

So, I took the wheel off and flipped it around. The sides reversed, so it’s the wheel and not the frame. I measured the difference: 1/4" space on one side and 5/32" on the other. Does having 3/32" dish difference make the wheel weaker? Is there any reason I shouldn’t just ride it?

Did you have this problem before he trued it? If he has a Park truing stand it could easily have the automatic dishing function out of calibration, and that would cause this problem.

I don’t know because I had a smaller tire on it before that would have hidden the problem. I only saw it because I went up to a 2.75" tire.

I pulled a 20" wheel over a couple of mm’s. Wasn’t too hard to do, but I took my time and I like that kind of work. If you are not detail oriented, and/or it does not bother you while you ride, live with it or have your LBS take care of it.

I would not shim as a quick fix because it will tilt the whole wheel for no good reason.

The strongest wheel would be symmetrically dished, but look at all of the rear road bike wheels with serious asymmetrical dishing. You aren’t really talking about enough difference to have much effect on strength.

Will that small difference weaken the unicycle over time at all? Or is it fine?

I have been building wheels since my early teens, and so I would fix it. If I didn’t have the skill to fix it I wouldn’t worry for a second about the strength.

If that wheel taco’s or goes out of true I feel confident saying that it won’t be due to the offset dish. It won’t harm the rest of the uni either.