I found these bearings on ebay and they have the exact same specs as the KH bearings on UDC: 20mm x 42mm. On UDC they are $8 EACH! On the ebay site they’re only $1 each! Brand new.
The add says they are for yamaha snownmobiles, but they also say they are commonly used in many different applications, so I bet they are the same as the KH. CHeck this and tell me what you think.
good find, but those have a maximum rating of 15000 rpm though, clearly not suitable for unicycling…
they look right and it makes sense. I would not buy bearings from UDC instead i would go to NAPA as bearings are bearings there is nothing unicycling specific about them.
Nice find though a buck a bearing is cheep, i think they are around $3 each at NAPA (but don’t quote me on that)
Cool, and what’s also great is that they are located not far from me and they allow pickups, so that saves me about $10 shipping. So yeah, a buck a piece is a way good deal. The same ten at UDC would set me back $80 plus at least another Jackson for shipping. I’ll report back on how they work out.
Does anybody know the exact thickness diameter of the 20mm x 42mm KH bearings??? UDC only idicates the ID/OD but not width.
You need to check the part number on the bearing, then google it.
Joe
Thanks I just measured my existing KH bearing; it’s precisely 12mm, so I’m in luck! YES!!!
Hey Terry–
I bought these exact bearings from this seller back in September or October, when I swapped my son’s DX wheel onto a KH frame. They’ve performed fine. Heck, even if they don’t hold up that well, I have so many spares it’ll take a while to burn through them! I never checked at my local NAPA, but at the local bearing shop they wanted more than $50 for a pair.
$50 a pair?? hOLY SH#T! That’s criminal! 
Well, you do have to be careful about what you ask for. There are different specs and tolerances for bearings even though they may have the same dimensions and bearing number. If you don’t ask correctly the bearing shop may quote you the higher priced item.
You can find bearings that will fit a unicycle that are $25 each. They would be over speced for unicycle needs. Machined to a higher tolerance than needed. Overbuilt in other areas than needed. There is a big difference in machining cost between something that is speced to ± 0.005 inches and something that is speced to ± 0.0005 inches. Both would fit on a unicycle, but in one case you’re paying for way more dimensional tolerance than you need. (note, I’m picking those numbers out of the air. They’re not the actual tolerances of any bearings that I know.)
Buying from a bearing distributer is almost always going to be less expensive that getting the same bearings from a bicycle shop or a hardware store. You end up cutting out a middle man and an additional markup or two.
The 6004-2rs (42, 20, 12mm) fit the old KH/Onza hub and are a fairly common size.
If you have a new KH 07 it will have an blue ISIS hub and will need 42, 22, 12mm bearings, these are a bit harder to find (I believe).
jim
Correct me if I’m wrong, but doesn’t RPM stand for Revolutions Per Minute? I don’t know how fast you ride but my max RPM is a bit more than 200, you mean to say you pedal 75 times as fast as me on my highest speed? I’d say it’s physically impossible but like I said, correct me if I’m wrong.
gliding down the side of the eifel tower (france)?
Peter just pointed out Blegas was being sarcastic, I’m a little tired haha sorry 
Wow! UDC must’ve JUST changed their website because yesterday when I checked (and I have TWO witnesses!) it said the new '07 KH bearings were 20x42!
Hey,
The bearings for the '07 KH Moment hub are here:
http://www.unicycle.com/shopping/shopexd.asp?id=1015
They are 22mm inside diameter, not 20mm.
Unfortunately that’s not a standard size- it was made specially because nothing was available. The only brands using that size are Qu-Ax and KH.
Kris
Wow, you go pretty slow!
I sometimes peak at speeds close to 56,548,668 miles per hour on my 20", and those can only take 56,548,667.8 miles per hour. At those speeds, I would never want catastrophic failure in my bearings.
Edit: good thing they don’t even fit, I might have fallen victim to them.