Nimbus ultimate wheel broke. Advice?

Hi, folks. a long time since I posted in here. Busy busy, and little time to ride, never mind write about it. Some of you may remember I was pretty much a daily poster in this forum until about 6 years ago.

Until earlier today, I had one of the early Nimbus ultimate wheels: 24" wheel with 4 oblong section steel spokes with the pedal sockets brazed onto the surface. I bought it, ooh, about 8 or 10 years ago, but it’s only been ridden for a few hours.

I was out on it today for the first time in over a year and had just got back into my stride, regularly managing to freemount and do 50+ pedal strokes before dismounting in a semi-controlled manner.

I did my longest single ride of the day: 112 pedal strokes (woohoo!) and then suddenly heard loud clicking. I dismounted and checked and found nothing wrong.

I remounted and the left pedal just folded away under me. The metal of the spoke had torn away around the edge of the brazing. The pedal was still firmly in the socket, the socket was still firmly brazed to the surface of the spoke, but the surface of the spoke had simply torn along the line where the thick and slightly uneven brazing meets the thin and uniform wall of the spoke.

I am not angry or complaining - I’ve had it for years and it’s far outside any warranty. However, I am disappointed because I know it has only had about 5-10 hours’ total use. Clearly it is all those falls onto the end of the pedal when I was learning that have created some fatigue at the obvious weak point.

I have looked at the new one on and it is different in approximately 3 ways:

A more complex spoke pattern instead of a simple right angled cross. The new one is a sort of 6 armed swastika.

Aluminium rather than steel. Lighter, but is it as strong?

It says “reinforced pedal bosses” and the photos appear to show that the pedal bosses go through the spoke rather than simply being brazed onto the surface.


Has anyone else had the same failure that I have had?

Does the new design adequately address this problem?


I have the same ultimate wheel and i have been worrying about failure too. When i upd or jump off it falls on its side with a loud clang. I have installed aluminum pedals because these had spikes but i guess it may be better to replace them for softer ones. I would be like to know if these failures are common on this model…

Hi Mike,

Yes long time no see. But that counts for pretty much most of the more fanatic. I guess “we’ve” moved to social media.

I was there when this design was born, at the workshop of Semcycle (but it’s remarkable how quickly other companies copied it).
This concept was found unintended, and so not designed with a mind to address strength.
One reason to make them was they were friendlier for ankles.
But yes, it probably is stronger, but sounds like not for the problem you seem to describe; the best is to have the pedal whole all-trough (such that two sides of the spoke carries your weight), and not on-surface.

Why rather aluminium? I don’t see lighter as a benefit. And it’s strength is less than steel.

But one advice: in stead of buying replacement, buy new bumpers, and go to the next level; start learning dragseat, you seem to have already enough skill for it.

I have the Nimbus ultimate 28". It is very strong. I riding down stairs with it, higest drop was 40cm, and many Times it falls to the Side and the pedal Hit the ground.

Thank you to those who replied.

I have now ordered one. I may do a bit of a write up on it later.

please do. I would be interested in your experience with the leg-tire friction problem. The ultimate wheel comes with a tire which is not an optimal choice in my opinion.

Remember those soft plastic inserts you could get for pedal protectors? They fit a variety of pedals but not all. Something like that would probably be good protection for an UW, especially when learning.

I never thought about it on mine, since I had a plywood one, built on a Tommy Miller UW Insert. You can’t go wrong with heavy chunks of steel! It’s just heavy. I only ever worried about my pedals breaking. For the most part, I think what I had on there were plastic pedals with molded-in pins. Also, from 1986 - 2000, my UW was owned by Jack Halpern, who was a much, much better rider of one. It probably didn’t get dropped nearly as much during that time. Then it returned to me, and I haven’t spent much time with it…

UW frame comparisons can be difficult, because it’s usually more about build quality than materials or even design. A little rough spot in a weld could make the difference in what happened to yours. Material-wise, aluminum is more brittle than steel. But as it’s lighter, it might not fall quite so hard, etc.

Good luck with your new UW! And your old one can probably be repaired by anyone who likes playing around with molten metal. :slight_smile: