Nimbus cranks stripped during attempted removal

I went to swap out my cranks for the first time on my Nimbus Touring 29er. The crank arm won’t budge but the threads came out. I am super bummed. If I can get the arms off I at least have the other cranks to use. Going to take it to the LBS soon but wanted to run it by you folks too.

I want to get up and running ASAP!

If all else fails, you can use a bearing extractor. The nimbus/quax aluminum is poor, so watch out to go nice and slow when working with them.

Also noticed that the QU-AX replacement cranks I bought dont have the flanges in the middle of the spindle hole…Will they be bolted in?

That doesn’t look like an ISIS crank extractor; it lacks the ISIS foot. That could be your problem.

As Danni noted, a bearing extractor could get the crank off. Or possibly just riding it without a bolt for a while. Problem is, you may have damaged the threads which hold the crank bolt, if you tried to extract the cranks without an ISIS foot.

I tried it first with the foot. Saw it stripping so I took the foot off. I verified that the foot would fit through the flanges and realized that I should be using it. Having said that the inside (crankshaft) isn’t damaged, luckily.

Riding it unbolted is a good idea. I don’t have a bearing extractor so in the interest of saving time and preventing further damage I will take it the shop. Hopefully they can expedite things.

Those Qu-Ax cranks are super-light, but the metal is incredibly soft; they’ll strip at the slightest provocation. [Insert yermom joke here]

It really did strip easily. I wasn’t putting gorilla power on it by any means.
I have successfully stuffed some calories down my neck so off to seek professional help.

[I’m fresh out of yer mom jokes but that was good for a laugh anyway]

One hour later…

Just got back from LBS. One of the mechanics was working on it hesitantly when he went to answer a phone call. The older mechanic asked if I had been helped. I told him that I had but invited him to check out the situation. He managed to thread in the crank extractor and try the straight forward method briefly. Then he said “Let me heat it up a little bit”, and disappeared to the back. He was back in no time - cranks removed! He just hit it lightly with a torch and tooled it off. Chalk it up to experience, I never would have thought of that.

He tried to charge me 10 bucks but I gave him 20 because I was so happy to get on with my life. :smiley:

the “flanges” were actually the splines and the cranks match up. They went on about half way and then I had to force them down with the allen bolt. Still might be a little more gap on the right side. I am hoping that if I keep tightening them after every ride they will end up perfectly set.

Glad I didn’t wait to do this last minute before going somewhere. Scares me a little about swapping cranks in the future.

Frankly, I wouldn’t swap the Qu-Ax cranks unless I absolutely had to. They are that finicky. Most other ISIS cranks (including the Nimbus Ventures) should be fine with relatively frequent swapping.

That is valuable advice. I was thinking of buying a few sizes actually and I am very glad to know that before plunking down some more cash.

Maybe these and be done with it…A little more dough but less time and trouble down the road.

I have swapped Qu-Ax cranks on a Nimbus unicycle several time without any problem. With the problem you present, I will be sure to fully thread the crank remover before apply pressure on it.


I’d go one size down : ) but I love my 125/150s on the 36in

they make a 110/125

Bummer. I’ve not had a problem with the Qu-Ax cranks on my coker, but then again I don’t swap them very often - tend to ride everything on 145s. I’ve always found that ISIS cranks don’t need so much force to pull off as square taper ones anyway, so it’s weird that yours managed to pull the whole thread out even in softish metal. Are you sure the puller wasn’t cross-threaded?

Out of interest - were you using spacers between the cranks and the bearing to act as crank stops? If not, then the crank would go on much tighter before it stopped, and need more force to remove it.


Yeah, that is the key, if you don’t thread your crank puller in quite a bit you are likely to strip most cranks, not just the qu-ax. I swapped various qu-ax crank sizes on my ungeared 36 quite often without any issue.

The crank puller wasn’t cross threaded but was probably not in all the way at first. Having not done it before I didn’t know how far it should go. I’m sure that’s where the trouble started.

There are spacers between the cranks and the bearing but there is probably 1/4" of play between the spacer and the crank arm. The bolts are in barely above flush and that’s as far as they wanted to go. Used a rubber mallet then torked them down with the allen key. They seem totally stable but I think the old ones were down farther.