Crank bent, or axle twisted?

Hi guys,
I recently (about 2 weeks ago today) purchased a 24" unistar, 48 spokes, all ChroMolly frame, with alluminum cranks. I have been using it to do trials stuff and jup off of almost-two-foot-high walls (but that isnt often, usually its just something the height of a bench). I noticed last weekend that the cranks were not in a straight line with each other as they should be, one or both (I don’t know which) has gone slightly in one direction or another. I don’t notice any actual bending in the crank itself. But they are definitely not in line with each other. On one side they make probably a 170 to 175 degree angle instead of 180 degrees. I wanted to know if the cranks were bent or if it is at all possible that the axle would twist. I have never heard of the latter happening, but since I am not too experienced with trials, I am not aware of the wide array of possibilities in breaking a unicycle. I hope that the cranks are just bent, because that’s a cheap fix, however like I said before, I can’t notice any bending in the crank itself. Please help me. And, no, I can not provide a picture as I am not handy enough with a computer. Sorry.
Thanks ahead of time for any help you may provide me.

BTW…

I have no idea about what kind of hub/axle it has. But I can tell you that it is the original one I bought it with.

its most likey that your crank is bent since they are of a softer medal.

get some new cranks but lay off the drops or get a trials uni with a stronger (splined) hub.

Unistars are great uni’s but not for badass trials stuff,get?

i have EXACTLY the same problem. It’s the hub on mine that is twisted though. I’ve had to buy a new hub, but the cranks were perfectly fine. One way you could test if its the cranks is to put a spirit level on them. but my hub bent from a 5 1/2 foot drop on a UDC trials uni. i’ll see if i can get u a pic of the uni if i get a chance.

I have the same problem, I have a Torker 24 and the hub is twisted. The cranks are not bent on mine.
-Isaac

My cranks bent first, but then my hub also twisted. James, how about a pic of the drop?

Andrew

Bent cranks, grrrr!

Yea, ive had a LOT of trouble with my Pashley Power Muni… first the cranks came loose after small amounts of jumping and dropping… two days after i got it in the mail! So Unicycle.com was nice about it and sent me some replacement cranks… so i put them on, and now 3 months later, they are loose again AND bent~ from nothing greater than a 2ft drop…

I spose that just means next time (or maybe now) I am going to have to spend mucho’s dinero next time and get a splined hub w/ cranks that wont give out… do they make those to fit lollypop bearings?

For now I’m saving my money for some Kooka cranks… and if those go out, then i just might sit down and cry…

Re: Bent cranks, grrrr!

With tapered cranks you have to keep an eye on the cranks to make sure they don’t get loose. You’ll need to regularly tighten them.

Use grease on the tapers when installing the cranks. The grease really helps you get the cranks tight and snug on the tapers. Then use red (high strength) Loctite on the threads of the retaining nut. The Loctite will keep the retaining nut from working its way loose. As long as the retaining nut stays tight the cranks should also stay tight.

Kooka cranks aren’t going to solve this problem. Using Kooka cranks will just mean that you’ll damage $110 cranks instead of $25 cranks. Riding with any crank while it is loose will damage it. Even more so with aluminum cranks like Kooka because the softer aluminum tapers will get damaged a lot faster than steel cranks.

Use grease, use Loctite, and get used to checking the retaining nuts before every ride.

Hei

I has the exact problem in the learning stages, But it was a very stupid move, I got real pissed an threw my unicycle. Crank was bent and had to straighten it out. I got issuses when im mad, people find it hysterical though.

Cranks can bend, axles can twist, or both. But if your cranks are out of line with each other, it sounds like twisted axle.

Cranks usually start by twisting themselves, meaning that the pedal will start to slope down and away from the unicycle. For a crank to bend in relation to the opposite crank is highly unlikely. This does not apply to multi-part tubular cranks, such as splined ones, which are more likely to break than bend.

Note: This also doesn’t apply to cottered cranks and axles. It is very common for cranks on a cottered axle to not line up. If you have this situation (not you but anyone), make sure the cotter pins aren’t pounded in from the same side. They should enter from opposite sides for best results.

Anyway, if your axle has twisted, this usually means it’s on its way toward breaking. The forces acting on a unicycle axle tend to make it want to twist, and when the metal starts to fatigue, I’ve had axles that were in a “twisted” position for a while before breaking. Sometimes a long while, but usually not so long.

If you were to take the unicycle apart now, you’d probably be able to see cracks in the area where the axle is twisting. This means the metal is starting to give way, but most of it must still be intact. Ride softly on that axle.

Suzue axles are very good for standard axles, but my own twisting experiences are with those axles. Fortunately for the unicyclists of today, we have the option of upgrading to one of three currently available splined axles. Only a few short years ago, there were none.

4 diferent splined axles to be pedantic,
in chronological order,
dm,
profile,
onza,
kh.

but, you can do trials moves on a frestyle uni,
just don’t do drops or gaps over 1 foot,
drops and gaps are actualy farily easy compared to the moves that will make you a good trials unicyclist.

theres technical stuff you can work on that won’t break your uni…
like riding on railings, find a low down rail to practice on. start with a wide one and work it down.

or doing pedal grabs,find a ledge, jump up land on just your pedal, then swing the uni up onto the ledge.
the easy way is to land on the crank and pedal.(crank grab)

or crank flips, jump up and do a half rotation of the wheel.

or foot plants, ride up to a ledge, stick a foot on it , push off and land back on the uni.

if you realy want to do drops then learn how to do them hopping on the wheel. it won’t break your axle or cranks.

but if you do want to break stuff then have fun…i did.

Re: Re: Bent cranks, grrrr!

The second time when I installed the cranks, I used the lock-tite that unicycle.com sent me with them, and I also used anti-sieze on the tappers, as they recommended to me…

I’ve been reading up on some older forums about using presses or mallets to get the cranks on tight before i even put the bolt on, but I never came to a conclusion about whether or not that was neccessary. :thinking:

I really dont know what to do…

Re: Re: Re: Bent cranks, grrrr!

look at the faq,

i highly reccomend using a press or mallet. i killed a few unicycles by not putting replacement cranks on right.