Who has broken a good cotterless wheelset? And how?

So this is something I’m curious about:

I’ve seen plenty of people recommending other riders get a splined setup because they’re stronger than cotterless - and this is certainly true. There are definitely people who need splined setups in order not to break their unis regularly and save cost overall - I’m not disputing this.

However: I do wonder how many cases of people disliking cotterless uni wheelsets is the result of a bad experience with poor quality cranks / hub. Many have damaged things just by hopping up and down curbs. If folks bend the cranks themselves then that’s surely nothing specifically to do with the cotterless fitting. Damaged axle/crank contact surfaces are partly due to the limitations of the design - but in many cases isn’t it just because people are moving outside the boundaries of the cheap uni many start off with? And twisted hubs… that again seems like a case of a cheap hub rather than anything to do with the cotterless axles.

For a concrete example of a decent cotterless hub, take the Nimbus wide (or ultra-wide) hub - who’s broken it and how? For cranks, I guess there are more options. The “standard” cheap-uni steel cranks aren’t very strong. I’d think alloy cranks might be more likely to wear badly at the axle interface. But steel cranks shouldn’t even suffer from this so much if properly fitted.

I guess what I’m wondering is: When people say cotterless unis are really weak (rather than just “weaker than splines”) are they basing that on experiences with bad components or just incredibly extreme riding?

I had a nimbus II muni, this was before the nimbus wide crmo came out but it still had a quality hub. I ripped the end clean off the hub. I very much doubt I ever dropped 2 feet on it, but i used to hop around a hell of a lot and attempt to do trials.

i agree about the strong cottorless stuff. black widow cranks to udc hubs are f ing strong.

ps. i bent a steel crank on my freestyle uni

some cotterless are way stronger than others.
i know that for a fact.
but i could break any of them off an 8 set doncha think?
thats not even that extreme.

I’d heard about black widows being a good cotterless choice (maybe from you!). My theory is that for many trials riders (and even more so for muni) a udc cromo hub could get lighter cheaper setup whilst still being plenty strong enough (and having the option of fitting short cranks if you wanted to cover some distance).

These days I do lots of hopping on my 20" (cheap noname hub), on my Nimbus 29er (UDC wide) and my UDC 36er (UDC ultra-wide) - all with upgraded cranks. It’ll be interesting to see which (if any) break as a result.

Well, maybe you could :wink: Roger Davies has apparently done plenty of 3-5ft drops on his cotterless nimbus trials without it breaking. It’s not really rated for that kind of use, though… Roger, like me, isn’t very heavy - and obviously his technique is very good. But I guess my point is, cotterless unis can be stronger than folks think - and I suspect most people who buy splined don’t ever really need it… especially for muni type purposes (excluding natural trials).

thats true. i see people who do a 6 foot drop 1 time and don’t ever do it again because they hit the ground so hard and they don’t like it. then they stick w/ 3-4 foot drops. I have seen a CX wheelset behave like a splined wheel.(its a friends and he rides the crap out of it, i have seen 6’ drops on it) IT is unbent. there is a little twist in the crank, but its nearly unnoticable. That said, my brother broke his on a 3’ drop. its all technique

splined hubs are only really needed for learning big drops/rolling gaps (w/ a big down factor)

I’m not exactly a big jumper or dropper, but my UDC hub on my muni has given no problems at all, not even a loose crank, in three years of fairly heavy xc use, including being dropped lots of times on the Dartmoor granite.

I’m actually of the opinion that steel cranks are more prone to coming loose than aluminium ones. My theory is that the ally deforms more on fitting and actually provides a better interface. But it could be that I’ve just never had a good enough steel pair. I didn’t get problems with my original steel cranks on my muni, but most of the mileage has been done since I swapped to the ally ProWheel ones.

There’s a pair or steel “Bicycle Euro” cranks on my coker which have come loose once since I’ve had it (but it was when I dropped it on the road, so it was provoked). I removed and refitted it and it seems OK so far after a hundred miles or so, so we’ll see.

If my muni hub ever breaks I’ll probably replace it with a KH or something, but for now it seems like it’s plenty strong enough for my fairly rocky xc riding. I don’t do drops over about 18" and my riding style is much more rolling than hopping (I’m useless at hopping) so that probably has some bearing on it.


The most common failure on the square taper setup is the crank; the square-taper interface is just not designed for the kind of abuse we give it when we’re jumping around. I’ve killed a crank in the Kinetic Sculpture Race: Louise killed one at Moab this year. (And no one had a 14mm socket, because no one uses them anymore). Sam had a crank fail on a MUni ride in Oakland last year. I’ve also had a friend bend the Torker LX hub taper on a minor hop.

If you’re hopping and dropping, you need splines.

My findings are similar, although I have at various times taken off all my cranks and carefully refitted them with better bolts, which maybe helped…

Mmmm OK. Although I guess aluminium cranks would tend to bond when bolted directly onto a steel axle… I’m not an engineer, so I’m out of my field here!

I use Bicycle Euro on my muni and haven’t had any problems with them. ProWheel allow cranks on the 36er. Opposite to you :slight_smile:

I figure mine will last a loooooong time. I don’t think I’d put a splined hub on my muni, I’m not convinced that the rest of the wheel isn’t the weakpoint anyway! One fine day I may get a trials / technical muni, but that will not be for a while; right now the unis I have do everything I want.


they hold up fine for normal ridding, they start to die when doing 2ft drops. then you get a splined hub :wink:

Mmmm. I just suddenly got really curious about who on here had actually seen a decent cotterless hub setup break… I’d seen lots of talk about cotterless being weak, just not seen many people with a good cotterless setup saying that they’d broken it…

My first muni had a UDC wide hub… I had to replace the cranks every couple months or so since they’d constantly deform / bend from repeated drops. After getting some decent cranks on it, I snapped one end of the hub off doing a 3ish foot drop with a bad landing…



P.S. Don’t be a twit like me, wear your gloves and helmet.

Youch! That looked painful! I guess I’m not surprised that it’d break under those conditions. What cranks were you using when you kept bending them? What did you switch to?

Mmmm. Strange how gravity seems to affect your head more when the helmet’s not on it, isn’t it :wink: I wonder if your suggestion of helium filled tyres could be applied to give my head more bouyancy. A coworker came into my office earlier, looked at my uni and said “I’m tempted, but I don’t have my bouncy head on today”.

FWIW, apparently the UDC hubs got stronger not long before I bought mine (about three or four years ago?)

I’m not going to claim they’re as strong as splined hubs, but I’m surprised how well mine has stood up to the rocks and mileage, even though I don’t do big drops. When I bought it I considered a KH hub, then decided against it due to cost, but I didn’t expect it to last this long with no problems at all. I reckon they’re stronger than a lot of people think.

Now I’ve said that mine will probably snap tomorrow…


I had a monty trials uni and within no more than ten minutes of having it I broke the hub doing only a small drop no more than 3ft, I bought the UDC cromo hub which is suposidly the strongest square taper/cotterless hub, this lasted about two months but after a few 5 and 6 sets, genral jumping and smalldrops around 3ft and droping in on a 6ft quarterpipe a few times it died so I decided to sell my monty uni and buy a kh 20, comparing the size of hub and cranks on both unicycles the monty looks tiny and the kh looks huge theres a huge amount more metal in the splined hub and cranks than there is in ths square taper, looking at the kh hub I thing your more likly to break bones than your hub :smiley:

I have wrecked two sets of cheep cranks on both my trials and MUni and both hubs seem to be in perfect shape. Three of the cranks were steel and developed play in the crank/hub interface and one set was cheep aluminum alloy cranks from an old road bike. They bent but the interface was fine. I think a good set of strong alloy cranks would do the trick for my MUni but i should get a splined setup for trials.

I have a Telford muni (it sadly hangs mostly unused in the garage these days) which came with a specially-hardened Suzue hub custom-made by Geoff Farraghan, who designed and sold the Telfords (beatiful frames, by the way). I rode it hard for probably 4 years before getting a KH24, and it never developed any slop or play in the crank-hub interface (it had alloy MTB 170 cranks). I didn’t do aggressive, high drops or the like, but the trails around here are very rocky and rough and I weigh a little over 200 lbs. It also stood up to lots of stair-hopping and small, 12-18" drops. It’s a strong, reliable setup. But it wouldn’t fit a 3" tire or brakes, so I retired it for the time being. It’s probably got a 3-lb advantage on the KH, even though it has a 26" wheel.

So Mark, I guess I’m supporting your supposition that for many people, a high-quality cotterless setup is plenty strong enough. For a man of my advanced weight, though, I must say that I feel a lot more confident in the splined setup I’m now running.

i was muni’ing with andrew carter once and he was riding someone elses 26" muni with a cotterless hub, he flew down the track and there was like a 3 and a bit foot drop thing and he did a massive rolling hop over it, it was the biggest hop i’ve ever seen it was insane, and when he landed the end of the hub sheared off.

it was the coolest unicycle thing i’ve ever seen.

i had cotterless, after doing 2 foot drops and 3 sets and trials, it finally gave in on a 4 set, axel just sheared off… i wouldnt ever try to take a cotterless of things i do now.