I was just looking at my trials wheel, and I noticed that the rim is noticeably bulging out around many of the spoke nipples. It looks like some of the spokes are about to rip right through the rim. Since I’ve heard of that happening to other people with Monty rims, I’m pretty concerned about this.
I’d like to solve this problem as cheaply as possible, but I’m not sure if theres any easy way around it. It seems like I’m going to have to rebuild the wheel.
I’ve heard of people using washers to spread the force around more on the rim. When I bought this wheel, I asked if maybe it would be a good idea to use washers like this, but I was told that a thicker gage spoke was being used, so washers wouldn’t be necessary. Apparently this isn’t the case.
My concern about using washers is that they would add a lot of weight right where you don’t want it. I guess if I’m going to be taking the wheel apart to add washers, I might as well spend the extra $ to get a new rim. Maybe this is the time to learn how to build wheels.
If anybody has any better ideas I’d love to hear them.
if your going to be putting washers in, you could do it one at a time, as in take one nipple off, the put the washer on, then bring the spoke back up to a little tention, the move to the next one. that would at least solve the problem of having to rebuild the wheel… then all you’d have to do is get it trued.
mine has been doing this for a while,
i’m just going to run it till it dies and get something stronger.
i’m probably going to get the arrow rim, but maybe the alex if the arrow is expensive/hard to get
i’d immagine that the main problem comes from the fact that on a trials bike the wheel is in a diferent position evey time you drop but on a unicycle its the same place every time that takes the load.
a perfect unicycle trials rim would allow for this by having stronger sections on two sides, but i suspect that the unicycle trials parts industry won’t end up that big in the near future
anybody hardcore have any experience with the alex vs the arrow?
I recently rebuilt a Monty-rim trials uni that a Unatic had bought off e-bay. Since the hub was stripped I had to do a rebuild. In the rebuild I used washers under the nipples. Luckily the wheel was never tensioned properly so there was no damage to the rim at the holes. I haven’t yet seen the wheel since it was delivered, though.
Personally, I’d rebuild the wheel completely, using washers. Be sure to get all the spokes back in the same place, or better replace them. Max’s suggestion might work but remember to expect some settling over time since you are not rebuilding from scratch. If you rebuild from scratch then your normal stress-relieving acitivities will deform the washers into place. This is a great time to learn to build wheels!
The thickness of the spoke has nothing to do with it; it’s the width of the nipple flange that counts.
The Alex DX32 rim has eyelets which seem to prevent that problem by distributing the force over a greater area of rim wall.
The Arrow literature says that the DHX’s center section was purposely reinforced to prevent this problem.
In all cases, you end up adding weight to the rim to prevent pull-through.
Wow I had no idea, Jag. I was just going by the website description. I suppose the reason is that as time goes on, and they get returns, they rework the product to improve it. The older product gets sold at a lower price, then the distributors have specials.
Alex does have a lot of flavors of their DX32 rims. They aren’t consistent with which ones have eyelets and which ones don’t. And their catalog descriptions are also inconsistent WRT the eyelets so the bike shops have a hard time trying to figure out which ones have eyelets and which ones don’t.
The 24" Alex DX32 rims that unicycle.com has right now are black with a silver machined sidewall and eyelets. I just got one last week. The pinned joint was nice and snug, no gap and the joint was smooth.
If you are going to rebuild your Monty rim/wheel,
Don’t use washers. The best way is to use the oversized Monty nipples. It will fix the problem you are having. I have them in stock if you need them.
The spokes must be loose for then to be pulling through the rim. The most important thing to maintain on a Muni or Trials unicycle is the spoke tension. Keep them snug and you won’t have a problem.
Riders doing the kind of riding you do will have to keep a closer eye on their wheel.
I find that the Alex rims are much better for wheel building than the Monty. It is really hard to get the tire off a Alex but it fits better than the Monty.
Alex makes the rim in many configurations. Eyelets are much better. I use and stock only eyeleted Alex rims.
I have lots of powder coated ones as well. Red, Blue, Yellow, Orange and stock black.
Check out what happened to Charles trials unicycle at the RIT / New York Juggling convention because he did a big drop with really loose spokes. I told him not to do the drop but he didn’t listen.
Oversized nipples are a better solution, but I don’t see why washers, properly sized, are not an acceptable solution as well.
I think Ben’s problem is with the rim bulging towards the hub as the rim material locally deforms. This would happen with the normal high tension of a well-built wheel that uses the Monty rim. Loose spokes wouldn’t cause the problem that Ben is presenting, IMHO.
Go to your local bike shop. Check out their catalogs, see if they have anything for Alex rims. At mine I have the option of ordering these rims with or w/o eyelet. So yes, they are consistent with which rims have or don’t have eyelets, if you go to the right source. As far as the machine sidewall, still haven’t dug any deeper on that.
The same thing happened to me, a while ago. I would always have a few spokes that were really loose, so i would tighten those, and as long as it didn’t hit the frame, i would just ride. this happened untill my rim started bulging and cracking where the spoke nipples were. I believe that my rim had spoke washers as well. I bought a Alex rim, and now everything is fine. I have yet to have any problems. I hope you find guidance in the way of the rim.
