Crank threads ripped out again = major frustration

After a week and a half wait for new cranks to arrive for my 24" Torker LX, I am experiencing the same problem these new cranks were supposed to fix. The threading in the pedal end of the cranks became ripped out. This time I was trying to do SIF and the pedal ripped out…not completely out though; it’s crooked in the crank and wobbles, but cannot be unscrewed and taken out by the fingers.

I’m really frustrated right now. If I have to wait over a week again for new cranks I’m not going to be too happy. I’m thinking about chucking this damn Torker and just spending the extra bucks on a much more durable unicycle. I need a unicycle to take with me on my move to Prague that isn’t going to crap out on me all the time. I don’t think the Torker is going to be that unicycle anymore.

Are there very strong cranks out there that will keep this from happening or could it be the pedals? The pedals I’m using are cheap ones. And what about rethreading the cranks? How does that work?

I’m not sure what my new move should be. I was very tempted to order that Onza 24" MUni that’s on sale at UDC when the Torker broke again…I just need something that will happily handle the abuse of a 215 lb person.

Thanks in advance for any advice.

My KH24 2004 model has handled my 210 pounds just fine for eleven months so far, except for the pedals and tire.

I didn’t know anything about muni maintenance when I got it, so when the cap fell off the pedal, I ignored it and the lube dried up and killed the pedal. The tire has also worn down from continual use. Neither of those problems had anything to do with the quality of the unicycle though.

In the future I will purchase sealed pedals, seems much simpler to me.

Don’t trash your entire unicycle because of pedals and cranks. Just get better quality cranks and pedals because they will make your unicycle feel a whole lot better.

There are some very good crank arms out there. Go to UDC and buy two pairs of crank arms, different manufacturers. Try a pair of BicycleEuro, and a pair of Nimbux X if you are going away and are worried about not being able to get new cranks. Actually, UDC is now located in Germany, and Germany is not far from Pargue, so there is no need to panic. Get better pedals. Aluminum Muni pedals. You will be fine.

Are you sure that you did not overtighten and/or cross-thread the pedals?

j.

Since the same thing happened twice your’e obviously doing something wrong. Either you’re way over tightening your pedals, or you’re putting them in teh wrong sides and just forcing them or something. Or ther threading on the pedals is screwed up. Take it to a bike shop explain the problem. The most you’ll have to do is buy new cranks and new pedals, let a bike shop install them for you, since htey know what they are doing and it will eliminate that component formt eh equations.

yeah or is your wheel backwards in the frame and the pedals have been installed into the wrong left/right specific cranks?

if you see any medal shavings anywhere, thats a good sign somone messed up.

I did let my LBS install them and I’m nearly certain everything is where it should be. There are metal shavings, however. The pedals are old…I’m hoping maybe I’ll just have to get new pedals.

If it’s the cranks again, what are some types of very strong cranks that I should look into? The Nimbus X ones?

I can sure see why you’re frustrated!

With old pedals is it possible that the thread sizes are different? Just because they are the same diameter, maybe the angle of the thread or the density is different.

The new pedal solution would fix that.

I have Nimbus X cranks–they are really excellent! Light and strong, and they look really cool too!

Well, I went back to my LBS and they tried to retap the threading on the cranks to no avail. The end of the crank closest to the wheel has been widened so much that no pedal will fit without wobbling. We tried new pedals and still the same problem. It’s got to be that the metal in the cranks is too soft for the weight I’m putting on it.

Is it really going to be worthwhile to spend another $50-70 on cranks and pedals after already spending $40 rather than just getting a new, stronger unicycle? I am really starting to doubt the durability of this Torker. Maybe I can find someone to buy it off of me for $75 with the knowledge that it needs new cranks.

Has anyone else experienced this problem before? What cranks did you get that have held up? I guess I’ll just order a pair of the Nimbus X cranks to get me on the road again if that’s what people suggest. It just really sucks that I was only mobile for 2 days of riding before this current pair broke. Also, I don’t like the feeling that I’m limited in what I can try just because I’m heavier than the average rider. I should be able to learn SIF, to hop moderate heights (like 1-1 1/2 ft. woud satisfy me) and other skills without breaking something all the time.

The pedals were definitely not cross-threaded nor were they tightened too much. The guy at the bike shop has been in the business for 17 years and I definitely trust him, although he admittedly doesn’t know hardly anything about unicycles.

I just really want a ride that I can be confident in.

you can tap the crank for a larger diameter and then put in a thread adapter. And buy some new pedals

From the information supplied, I have three possible explanations for your situation:

  1. A batch of defective cranks. Highly unlikely, as it would probably have been noticed and reported by others. Very unlikely that both your pairs of cranks were from the same manufacturing batch.

  2. Your pedals may have had bad threads, or too much “junk” in the threads after the first set of cranks. This is the kind of thing your bike shop guy should notice, however, so I don’t think it’s too likely either. But if your threads were clogged up, they would tear up the threads on the new cranks a little, and be more likely to deteriorate as you hopped and rode on them.

  3. Your wheel is backwards, and the guy at the bike shop didn’t notice. If your threads aren’t too trashed, check and see. The pedal on the right side (as viewed from sitting on the unicycle) should be threaded righty-tighty. The left one should be backwards-threaded. If they are on the opposite sides, your pedals will come loose from normal riding. This is the 90% probability of what’s happening.

Even though a bike mechanic should be well-aware of the importance of having the cranks on the proper sides, he may not be aware which end of the seat is the front. Or otherwise he just migh not realize that it’s more important on a unicycle than it is on a bike. Or, perhaps more likely, bike mechanics don’t think about the left-right thing, because they don’t ever need to consider it on bikes. The chain is always on the right side, and that’s that. It’s impossible to assemble a bike backwards, but with a unicycle it’s easy.

In my experience I would say that it is more like 99.9% that this is the reason. Pedal threads do not strip unless they are loose. If they are tightened correctly to begin with then, this is the way that they come loose.

Roger

i had the same prblem with my toker lx cranks and i weigh 90 lbs, then i had my toker stolen and got the onza, it works great

Would this explain my pedal’s tendency to clean the threading right out of the crank? Both times it’s happened it has been on the right side. Also, the pedals don’t come loose so that they can be tightened up again; they become permanently vertically wobbly and very hard to unscrew. Once you get them out you see metal shavings and no more threading inside the crank while the threading on the pedal remains perfectly intact.

I ordered a pair of Nimbus X cranks on rush delivery to get me back on the road, but I’m not too convinced that this will be a permanent fix. I’ll have the guys at the bike shop check whether or not the wheel is on backwards also.

Thanks a lot for the responses everyone. We’ve really got a helpful community. It makes me very glad to be a part of it (regardless of the minor techincal headaches that come with the territory).

I had a pedal once that would never stay tight. It would always come loose. Turned out that the pedal threads were slightly out of spec and slightly too small. I replaced those pedals and no more loose pedal problems on that uni.

It is possible that you have a pedal that has bad threads.

A big guy riding on a loose pedal could probably strip the threads out of the crank just by riding around norrmally.

I cross threaded a pedal recently. I cannot believe how easy it was. I put the pedal on finger tight and noticed it did not feel right so I took it off and put back on again, finger tight. I thought I had it right so I took the pedal wrench to it and … well it was messed up then. Grand Master 2T worked his magic on it with a thread tap and I am fixed at least for now. I will never take that pedal off again.

If your wheel is backwards, yes. You didn’t say if it was or not. But riding with the pedals on the wrong sides will always lead to them loosening up, unless they were put on super-tight, or with Loctite. Then, continued riding with hops and other forms of impact, will start tearing the threads up.

If i was in your place, i would epoxy-glue my pedals to the crankarms , and when it broke, i would change both pedals and cranks, since the threads probably is a bit damaged on both of them! =)

Cheers! :slight_smile:

Easy fix to this might just be to put the pedals on yourself, if you dont have to tools go to the bike shop and ask them if you can do it, tell them you are trying to learn the maintinece stuff. I’ve been to 4 or 5 bike shops that were glad to help out when I was in such a pinch trying to fix my unicycle or bike.

You may also want to talk to your LBS about getting some new pedals. I know I would want to swap them out if your problem happened to me twice. Also if they are torker pedals and your a bigger guy you probably want a bit beefier pedal anyway.

A side note almost all pedals and cranks have an R or L on them (sometimes both) to tell you what pedal and crank arm you have. If you still have the crank arms and pedals check to see if they match up or not.

Good Luck with the whole process.

Chex