KH/Onza Hub Limitations

[Probailer2]

@Erant

Whoops, sorry, havn’t read this.

And yes, I can justify this. My brother has ridden on a 24" KH for roughly… 2 weeks before bending was seriously apparent. Then he got new cranks under warranty, and those bent in 2 days! He’s now waiting for the new, stronger cranks to be supplied. His Qu-Ax wheelset is still in pristine condition, even after 1.5 years of serious abuse.

Wath newer cranks?Is there something I don’t know?

[Probailer2]

the KH/Onza hub:
Profile hubs have an effective, simple design that works OK, and they are pioneers in that they were the first mainstream manufacturer to make good splined unicycle hubs. But…they can be improved in several ways:

1. Profile splines are strong but prone to creaking due to manufacturing variations and wear and tear. The KH/Onza axle has a tapered section on each end, with a split washer that expands to compress the crank against the axle. Like all systems this requires maintenance (greasing) of the splines, but is an effective solution.
2. As Roger said, flange design makes a big difference for rim strength. The KH/Onza hub has a much better shape than any other uni hub for rim stiffness and strength, and for minimizing stress on the spokes. High-grade (7000 series) aluminum is much, much better for supporting spokes than steel flanges, such as those on D.M. or Koxx hubs. That is the big disadvantage of welding steel flanges to a steel hub.
3. The hub-axle connection KH/Onza is totally new for unicycle hubs and by far the best available. Profiles (and also the 2004 KH hub), used a keyway slot, which is weaker and prone to loosening and manufacturer defects. Each 7000 series Aluminum flange on the KH/Onza is machined separately and attached to the axle with the same splines as the cranks. This is way stronger and much lighter because it removes material from the centre of the hub (the centre of the KH/Onza hub is hollow except for the axle).

The cranks:
There will always be debates forever on the advantages/disadvantages of Aluminum versus Cromoly cranks. Aluminum is a lighter metal but the cranks aren’t necessarily lighter because the cranks are typically solid (except for hollowtech bike cranks), whereas Cromoly cranks are hollow (KH/Onza and Koxx crank arms are the same weight).

Aluminum is stiff but may be prone to snapping, whereas CrMo typically bends before it breaks- a good safety factor. CrMo may also be more durable to extended hard impacts, like we have on unicycles. Koxx cranks are smooth on the outside but also have no Q-factor (outwards flare), so they are actually more prone to hitting your ankle bone than the 2005 KH/Onza cranks. The shortest Profiles are 145mm. In my opinion this is too long for trials. 140mm is better for rolling hops, you are less likely to hit your pedals on the ground, and they are less likely to throw off your balance when pedalling along narrow beams.

Hopefully this info answers some of the questions out there.

Cheers,

Kris

This explenation of Kris makes sence to me and I will stick to my KH hub and buy some new 150mm cranks.

Peter M

[vivalargo]

Does someone actually know if Roger and Kris are addressing this beidning crank problem. It’s not just a matter of having good roll out technique. Many times on Muni you CAN’T roll out. There isn’t enough room. If they got the crank bend problem worked out the KH would essentially be pretty much perfect.

JL

[Probailer2]

@vivalargo

Does someone actually know if Roger and Kris are addressing this beidning crank problem. It’s not just a matter of having good roll out technique. Many times on Muni you CAN’T roll out. There isn’t enough room. If they got the crank bend problem worked out the KH would essentially be pretty much perfect.

JL

Except the little frame flex, at least mine has that:D

[unijesse]

yes i prefer kh butter over the land-o-lakes, it spreads easier.

[joelg_98]

my onza uni

i buy a onza uni and i have a kh/0nza hub and krank set ,and 2 day ago i eared a lil’ noise when i ride (tac tac tac)

[gerblefranklin]

I may be the black sheep here, but i don’t maintain my profiles. I anti-seize them about once every 20-50 rides, and that’s it. I’m pretty hard on them, but they still last.

Creaking hasn’t been a problem with either set I have. I find the bigger problem is my muni hub seems to have a loose keyway, which sucks ass. It’s an old hub, though, been ridden for over 4 years (1 year by kris Holm, 3+ by me). Word is profile has fixed the keyway issue.

So what if stuff creaks or moves a bit? So long as you can ride, shut your mouth and enjoy it. I don’t cancel a ride because my canks aren’t perfect, I just go out, have fun, and see if I can fix them when I get home. If I can’t fix them, I either start setting aside $$$ for replacements, or try to ignore the problem and enjoy myself. So far I’ve just been of the mind to shut up and ride.

If any of you are THAT concerned by the quality of you unicycle, maybe you should reexamine whether you’re in this sport to have fun or buy more crap. All of the splined hubs out there are excellent, and you can’t go wrong with them. If you are an inexperienced enough rider to not know the strengths of the various hubs, I seriously doubt you will belable to break any of them. It’s unreasonable to expect more than 2 years out of any hub once you are doing 5+’ drops regularly.