Broken Nimbus 36 frame

Here’s some pictures of my Nimbus 36 frame. The two front steel round tubes have a crack on both of them, right at the small hole (relief hole?).

Just a warning to others with N36 frames to keep an eye on that point.




Did you use a brake? I noticed my frame flexed quite a bit when squeezing a HS33. Perhaps more people should use boosters.

Yes, not a magura, but a cable brake. although I did use maguras for a little while with it. However, a frame still shouldn’t fail like this…


Well, atleast the welds seem to be strong :wink:
But to bad it’s broken, I think you can get a free warranty replacement.
Just try

Actually, I’m not going to even try – mainly because I don’t need a new frame now that I have a KH 36. Even if I did need a new one, I would probably just buy it, in order to help support the unicycle community (especially the key manufacturers, KH, Nimbus, etc).

Plus, I probably got 2 thousand miles out of the frame (a guess), and if I really was desperate, I could weld it myself :slight_smile:

Eventually, this frame and one of Nathan’s old frames is going to turn into a V frame. Maybe soon…


In the unicyclist community “old” doesn’t always mean old, does it? :slight_smile:

Had you done any welding or powdercoating to the frame, or any other mod or treatments that made it go through any uncommon heat cycles?
Powder coating or welding improperly will fatigue and weaken metal.

Nothing against you or your skills, just curious?

The frame is clearly spray painted :slight_smile: (it’s chipping off all kinds). So, it hasn’t had a powdercoating.

I welded a bar on the back two fork tubes – the front tubes, which failed, were never heated at all. You do have a good guess; heating it could easily anneal the steel, causing to flex more and fatigue. Or, vice-versa, it could have hardened it too much, causing it to be too brittle and crack. However, neither is the case for the front forks. This is a true failure of the frame, probably due to the holes that came with it.

Granted, I did ride it pretty hard for a few years.


Like I said I was not doubting you’re craftsmanship or riding skills since I am new here and you can clearly ride and have a good grasp on shop knowledge too :smiley:

Being a motorcycle stunter I have seen many good powder coat jobs trashed beyond belief. 400+ lbs into concrete multiple times a day will do wonders to paint, powder or any other material for that matter.

I look forward to seeing that frame in its next life you have planned for it

I had the exact same failure happen on one side of my Nimbus 36 frame. The little hole (which I believe allows gas to escape when welding) seems to be a weak point. I’m going to check with Roger and see if it can be moved. Perhaps if the hole wasn’t located at the curved part of the frame, it would last longer?

That being said, I wasn’t too worried as I had put several thousand km on the frame and my schlumpf arrived the same week it broke, so the Nimbus got shelved anyway.

Lucky for some. With no Schlumpf on the way, I hope my holes don’t crack. I just checked mine and I can’t find any cracks there- I don’t use a brake though so hopefully they will survive.

Definitely let him know…feel free to include my pictures.

I think they may have changed the position of the holes already. I have a frame from 2008, the holes look like they are closer to the seat tube than the brake mounts.

My Nimbus 36 frame just broke in the same place. I was going up a steep hill at the time it broke. I have had this frame since 10/25/2006 and have a lot of hard miles on it, including my fair share of crashing.

Time for a KH36 :slight_smile: