Qu-Ax slpined hub and crankset is 119 GBP or $139 USD…I’ve heard the KH hub is good…the one that looks like the second best, under profile is the Onza hub because it’s 40 spline, but i don’t know if you can buy just the hub.
That question may need rephrasing. All the hubs/axles I ever broke died not because of what they were, but because of excessive stress over an extended period of time. They didn’t break because they were square taper (or cottered), they broke because the workload exceeded what the steel could take. Splined axles are stronger because of their larger diameter cross section, not because of their shape.
For the gentleman looking for 24" unicycles in Spain, shipping from outside Europe may be difficult. Start with Unicycle.uk.com and Qu-Ax, and see if you can find what you need there. For drops and lots of rough terrain, splined axles are best. Which spline is far less important than the difference between splined and cotterless.
For cotterless, both Suzue and Semcycle hubs are very good. Beyond this, it depends on the type of riding you will do.
Since you seem to be looking for heavy duty, I recommend the KH. It’s the best deal for the price, and the axles will probably never break.
Yeah, that question wasn’t phrased very well, sorry.
Perhaps a better question to ask is for a detailed description of how they break (personally I can’t really see them breaking before you’ve destroyed the rim :)). I’d envisioned a bending due to repetitive heavy drops more than anything else.
As well as being larger, splines distribute the load over the axle more evenly, but it’s a balance, the more splines you put in the more susceptible to metal fatigue they’d be (I think).
Aah. They almost always break in the space between the crank and the bearing (at the base of the tapers). The reason they break, excluding super-extreme drops or other trauma, is from metal fatigue. Thousands upon thousands of hops, idles, starts, stops, and drops add up, and eventually the metal crystalizes and basically shatters. There must be pictures of broken axles out there on the Web, but I don’t know of any specific ones. George Peck’s Rough Terrain Unicycling video shows a great collection of broken parts, including a handful of little broken-off square tapers.
So in the vast majority of cases, it’s metal fatigue, rather than the taper or specific bits failing. Sometimes you can detect when an axle is getting ready to fail. If the cranks are no longer 180 degrees opposite each other, yet they’re installed properly and tight, this usually means the axle is partially compromised. It’s only a matter of time.
Not a worry, since the splines don’t break. the Stress is on the core of the axle more than it is on any individual spline, so the break is likely to happen all at once, rather than at one or more splines.
Splined axles are thicker, but otherwise they’re still susceptible to the same sort of fatigue that affects the skinnier cotterless axles. The question is whether it’s enough to not be stressed, or to be stressed so little that they last virtually forever. This remains to be seen, as people continue to push the envelope in unicycling.
Splined axles are stronger because of their larger diameter cross section, not because of their shape.
So it’s because they’re thicker?
Does that mean that a normal square section hub would be as strong if it were also thicker?
I’m asking because when I’ve read posts about splined hubs being the way to go for strength I’ve naturally assumed it was because of the splines.
Is it more accurate to say that the splines are there to lessen the chance of the axle/crank interface surfaces becoming worn?
Basically yup, though the square taper is an inferior way to attach cranks to the axle. Splined axles hold onto the cranks better.
Not really. The switch was made from cotterless to splined because that’s where the stronger parts are.
You could make a fat cotterless axle and it would be really strong. But you’d have to make your own fat cotterless cranks to fit the axle. Such parts don’t exist. It’s much cheaper to make the move to the stronger stuff that’s already being mass-produced. So, though there are multiple standards for splined axles/hubs, someone is already mass-producing cranks for them so we’re in much better shape to be able to afford things. The big breakthrough in the unicycling market was:
First - DM coming out with the first splined hub
Second - David Poznanter and others getting Profile to make splined hubs we could buy separately (I don’t think the DMs are available separately)
Third - The lower-priced KH and similar splined hubs. Now they’re a lot more affordable.