I was thinking about getting a profile hub to go on my trials uni but I’m not sure if it is worth the money. If I should get it do I also need the profile cranks?
Please correct me if I’m wrong, but you could have some 48 spline cranks made to fit the hub. I guess it’d probably end up being cheaper and safer to just get the Profile cranks. I don’t know whether or not you already know this, but splined cranks don’t all have the same number of splines. Profiles have 48, KH’s have 8 (I think), Onzas have 8, etc. Generally, the more the merrier (and more expensive). I got a Profile hub and crankset for my custom muni just to be sure I wouldn’t brake anything. I probably don’t need Profiles, but I think buying them was justified because I ride it so much and really want it to last.
i think Onza’s have 40
Well it doesn’t say how many splines it has, but yeh, 40 looks about right…
I have a profile hub on my Mountain Unicycle. I have never done trials but I imagine it would require strength in the axle. Profile makes a few crank lengths so they are worth having if you get the axle (they come with some sort of garauntee). They are far better than cotter-pin or cotterless hubs. Only thing negative about them is the clicking and creaking sounds they give out now and then. Apparently the hideous sounds are not doing any damage and some people just put up with it. Anti-seize or grease can eliminate the noises for some people, but others are stuck with the sound of the sturdy axle making itself heard . It is not a big problem it is just something that is not listed in the product description when you buy it. I think it’s worth the money to have a reliable hub.
Re: Profile hubs
The Profile setup is strong and is not likely to break or bend on you.
With the splined hubs you get locked in to using specific cranks with the hub. For example you cannot put Summit cranks or Onza cranks on a Profile hub. You’re stuck with using Profile cranks with the Profile hub. Not that that’s a bad thing. Profile makes good cranks.
If you’re looking for an option that is less expensive than Profile you could try the Onza trials uni.
The cost of the entire Onza uni is less than the cost of a Profile wheel set (hub, cranks, spokes, rim, and wheel build).
i’ve just bought a set of KH cranks and a hub and they feel v solid only with 8 splines, although i havn’t done anything major on it yet. onzas have 36 splines. there is a limit to the number of splines thought because the more you have the smaller they get so an infinit number of splines would leave you with a smooth shaft:( . i expect that profile, with 48 splines have the optimum amount of splinage for the cromo steel.
I wouldn’t get hung up on the spline count as a measure of hub strength. Just counting the splines and assuming that the one with more splines is stronger is not a reliable measure.
The general theory is that hubs made with more splines and smaller splines are stronger because there is less metal removed and the effective diameter of the spindle where the splines are cut will be larger and stronger. The spline designs with deeper grooves (like the 8 spline KH) remove more metal and if you look at the spindle where the splines are cut you’d think that it can’t be as strong because there is less metal there. But there is more to the equation than just spline count. Other factors that would affect the strength are the steel alloy used for the spindle and the crank, the heat treatment process, the machining process, the engineering design, The OD of the spindle, and more.
Engineering design is very important. Here is what can happen to a hub that should have had a little bit more engineering analysis done on the design. If a 70 year old man can break a hub there is something wrong with it.
More splines may make the cranks stay on better, however the more splines there are, the smaller they are and hence it takes less time for them to wear down. You can tell they’re rubbing because of the creaking noise so they must be wearing down to some extent. Supposedly profile cranks end up with the cranks spinning on the axle without turning the axle at some point. Doesn’t matter much with profiles because you can just warranty them, but maybe the ideal number of splines is a bit lower than 48.