I have a sun 24 inch off road flat top unicycle. It looks like the new sun offroad unicycle but is slightly different. I can not find it anywhere online and am not sure how to replace the bearings. I need new bearings because I snapped one, but I took it to a bike shop and they said it was an odd size and I would have to order then on my own because they can not buy them through the shop…I later looked them up and found them but shipping was wayyy to expensive so I did not order them. Any suggestions on what to do? Is it easier to get a new hub? Any suggestions would be great.

I’ve been looking at this Sun Off Road as my first unicycle. Would you recommend it? It’s not looking good that yours is already broken but I’m hoping you’ll say it was a freak accident or something overly extreme that caused it.

If it has a cotterless hub (square taper), the bearings are 17x40x12 If it is an isis (splined) hub, the bearings are 22x42x12

The cotterless bearings should be pretty common but the isis ones are best sourced from (unless you fancy paying through the nose for them).

The bearings can be swapped by any competent local bike shop or possibly even an auto mechanic using a bearing puller to take them off, then a length of pipe or a seatpost to fit the new ones on.

Dunno if that reply is in re Sun unicycles specifically or unicycles in general. Since the member who asked the original question hasn’t posted again or logged into the site in the five months since, I’ll throw in one extra tidbit.

For my 700c road uni wheel, I used one of the “Schwinn Unicycle 36 Hole Square Taper Crank Mount” hubs from eBay. They don’t include bearings and it turns out that they use funny sized ones: 6203-2RS-10, like a standard cotterless bearing except with a 5/8" inner diameter. sells them, as “Kit8194”. So “odd size” could possibly mean that, or maybe that data will be useful to someone else somewhere down the line even if not.

ooopsies. should have checked the original post date…

Bearings are often broken prematurely by either over tightening the bearing housings (finger tight is tight enough) or by hosing down the unicycle and washing crud in.

I would assume that the bearings are likely to be good enough to be used on a uni, we aren’t that brutal compared to what the bearings are built to do.

I agree with that. Unicycles seem to use standard industrial-grade sealed bearings from what I’ve seen, which are rated for loads well above what we ask of them. It stands to reason that the size was chosen the diameter of the axle shaft that goes inside and the need for that to be strong, since that’s what has usually broken. The bearings themselves are bigger than they’d need to be otherwise. Any of them seem to do fine as long as they’re installed right and not mistreated, as you say.

They’re also pretty heavy and therefore expensive to ship because of that, which the OP complains about. But they aren’t much help for your unicycle if they’re sitting on a shelf in a warehouse in California so it’s just part of the cost.