Again with the breaking!

General
1

My wheel bent today. So much that it jams itself on the rim. I suppose I should have it trued, but this is the second time. Should I just buy a new rim? And if so, what kind? I’m kind of hesitant about investing more money in this one because I’m saving for a better one.

2

DX32 rim :smiley:

http://www.unicyclist.com/forums/showthread.php?s=&threadid=32423

Im so unhelpful i amaze myself…

3

Re: Again with the breaking!

Perhaps. How far has it bent? One centimeter? Five?

Your best option is probably to keep saving for a new unicycle and true it yourself. Go to a LBS and get a spoke wrench and a crank puller if you don’t have one already. Go to a good LBS (defined as one with helpful mechanics) when they aren’t busy and have them show you how to use the tools.

  1. Remove the cranks. (Note - with a little charm this can be done with the help of the LBS mechanics as they show you how to use the puller.)

  2. Take the wheel off the unicycle, deflate the tire and take it off the rim. Put the wheel back on the uncycle.

  3. Rig up some sort of indicator to let you see how true the rim is. Some people use zip-ties, others use tape with a flap sticking out, others use bailing wire. Doesn’t really matter as long as it gives you a good visual reference.

  4. Turn the unicycle upside down and brace it somehow. Some people take the seatpost out and plunk the seat tube down into something. Others just get a friend to hold the frame. The setup doesn’t have to be particularly rigid but it should be stable.

  5. Sit in the plane of the wheel (hub hidden behind the rim) and spin it. Watch what it does. Use the spoke wrench to tighten and loosen the spokes so that a) the rim is round and b) the rim is flat, and c) the spokes are really tight so it won’t bend again. This is an art, not a science, so take your time. Never tighten or loosen a sopke more than half a turn at a time. Quarter turns are better. Really good wheel mechanics can true and tension a wheel in 5 to 10 minutes, but if it’s your first wheel it might take a couple of hours. Plan on a few breaks and some sanity-reparing activites. If you’ve got a good LBS then periodically take what you’ve got so far to them and ask their advice. (Trust me, if the LBS is worth anything they will be happy to help as long as you pick a slack time. I used to be a mechanic.)

  6. It’s possible that the rim is bent beyond repair, in which case you will need a new rim, but only the rim. It’s stronger and less expensice to put a good rim on your old hub than it would be to buy a cheap-o wheel. De-tension the old wheel by loosening the spokes in multiple passes (again, never more than half a turn at a time) until they are completely slack. Tape the new rim to the old one making sure to line up the hole for the valve stem. Transfer teh spokes to the new rim, remove the old one and start to tension the wheel.

  7. Put everything back together and ride off on your virtually new wheel.

4

if it tacoed twice it will taco again. either get new rim or if the uni isn’t worth it get a new uni and change the rim of the old one to a cheap steel one. that way you have a spare uni for friends to try. that way you can also have fun learning how to build a wheel.

my thoughts:p

john

5

Re: Again with the breaking!

“cyberbellum” <cyberbellum@NoEmail.Message.Poster.at.Unicyclist.com> writes:

> 5) Sit in the plane of the wheel (hub hidden behind the rim) and spin
> it. Watch what it does. Use the spoke wrench to tighten and loosen the
> spokes so that a) the rim is round and b) the rim is flat, and c) the
> spokes are really tight so it won’t bend again. This is an art, not a
> science, so take your time. Never tighten or loosen a sopke more than
> half a turn at a time.
…

Also turn spokes in groups in order to adjust one thing at a time.
For example, turn one spoke 1/4 turn clockwise, the next 1/2 turn
counterclockwise, and the third 1/4 turn clockwise to change roundness
without changing lateral trueness.

> 6) It’s possible that the rim is bent beyond repair, in which case you
> will need a new rim, but only the rim.

Isn’t it likely new spokes will be needed if going from a
single-walled rim to a double-walled one?

Ken

6

Re: Re: Again with the breaking!

Yes. Not because the old ones are damaged or anything, but they might be too short or long for the new rim.

That said, in my experience it’s ok for the spokes to be a couple of mm longer or shorter than the ideal length. As in one or two mm longer or shorter - if they are too long they can puncture the tube, and if too short they don’t engage enough threads in the spoke nipple so they might fail. Since the real plan is to get a whole new unicycle having a slightly “wrong” setup is probably acceptable. New spokes aren’t all that cheap.

Still, it would be worth running the spoke calculator and figuring out if a new set of spokes is warranted. If it’s 5 or 6 mm off then you really can’t build a proper wheel without new spokes.

7

I’ll true it myself. It’s rideable, and now I have a brake because the tire jams against the fork when I move really really slow (walk it).

By the end of the summer I’ll have 350 bucks. I’ll save up 400 then come and talk to you guys about what to buy.

And trueing it myself would be a good skill to learn.