ISIS bearing source 42x22x12, besides

Does anyone else think that Paying 10.40 for shipping a pair of bearings is way too much?

I need some ISIS bearings 42x22x12, Did anyone find them at their local bearing store? Thanks.

Isis bearings are not standard, you cannot find them at a local shop


one expression,-“e-bay”- !

Interesting but not surprising! I have some bicycle components which I bought just to have available in case I ever needed them and it worked out that those same components, as good as they are, then later got discontinued by the manufacturer, but at least I do have them. ISIS seems to be a great system but gotta have bearings to keep ISIS working. and so maybe stocking up on a few extra sets of bearings might be worthwhile.

One set of bearings can happily last you a few years or so depending on how you ride so personally I just have a couple of spares from UDC in my parts box.

I’ve bought enough other stuff from them over the years that throwing a few sets of bearings onto an order has been no big deal.

Among unicyclists ISIS is a popular system which apparently uses non-standard bearings. Now, I am not talking about going into the bearing business but having a few extra sets of those bearings on hand could not only satisfy one’s own future needs but could also become a trading item among fellow unicyclists, especially if those non-standard bearings ever become non-available to the little, tiny unicycling market for which those bearings are intended. Just consider that without good bearings ISIS becomes useless.


wow, not an unusual size! about $8 american dollars on ebay just do a little looking.

This seems like a good reason to get the real story about ISIS bearings being either standard or non-standard. Great if they are standard but worth knowing if they are not.

I see that Unicycle.Com does sell ISIS bearings on ebay. About $30 delivered for two. That is about twice the cost of “normal” standard bearings and a little more then getting them directly from UDC. I don’t see any other ebay sellers that has them.

It is strange that the bearing manufacturer does not sell them. Maybe they have some kind of restriction or just not profitable to mess with them because of the very low demand.

Thanks. I ordered 10 from China for $35.00.

Thanks, good to hear! That suggests, not confirms but suggests, that China has some need or use for these bearings and so at least for now it seems safe to assume these bearing are standard bearings. But I would also do just as you have done for that kind of money, that if I needed one set of bearings then I would order five sets, to then have four spare sets, just in case. At UDC the lower grade unis use 40mm OD bearings but the more expensive higher grade unis with ISIS use the 42mm OD bearings such as these, and so for the small money cost of these bearings it seems worthwhile to have a few extra, spare bearing sets at hand.

Can you share exactly where you found this deal?

There is this?
They appear to be designed for RC cars.

Bear in mind that not all ball bearings are created equally though. I’ve bought some 17x42x12 (for my square taper freewheels) and although they work, they’re definitely not made to the same quality as the bearings you can buy from UDC.

Definitely a non standard bearing. Here’s some choices I found, besides ones.

Here’s one I found on Amazon;

Maybe someone who has some 42 22 12 bearings can post a pic here of the bearings, with the part numbers shown. That might be useful to find more sources, too.

I also found something called KRIS HOLM KH ISIS MOMENT HUB Bearing Set from RCbearings , available at RCbearings or Amazon that’s NOT the correct 42 x22x12 MM bearing size, so stay away from this. I think he said they were 20mm ones.

And I’m sure the pictures aren’t the actual bearing in most listings.

I missed that one, pretty cheap price…
I did learn a whole bunch of stuff on bearings, including the bearing tolerance ratings, ABEC-1, ABEC-3 and ABEC-5 tolerance ratings. So I don’t have a lot of hope that I’m getting anything but the lowest quality.

Yeah, 20x42x12 is a far more common size. Plenty of bearings around designed to fit 20mm shafts.

I AM NOT recommending this but if 22x42x12 bearings are non-standard and suddenly become unobtainium, no can getz, and if 20x42x12 bearings are in reliable, standard supply then a machinist could chuck a 22mm axle into a lathe and turn the axle diameter down to 20mm in order to use the 20x42x12 bearings. Of course, reducing the axle diameter reduces the strength of the axle and also reduces the strength of the ISIS connection fitting which is why I do not recommend doing this but I am posting this here just as a future reference in case of a bearing emergency situation, possibly months or years from now. BTW, altering the inside diameter of a bearing would be a challenging thing to do, at least, and would introduce its own structural strength concerns, too.

And yes, I find this bearing discussion both interesting and quite worthwhile, gotta have bearings as they are not optional, thank you!

Here is an ISIS bearing. The numbers/ID are not standard either.


Or you could get BMX 22mm Mid bottom bracket bearings, and use a .5mm spacer made from shim stock. These bearings are 41mm O.D.


It looks like the mid bearings are 11mm’s wide, so it would also need a 1mm spacer.