Does anyone know the bearing specs on a Y2K-era Miyata Deluxe with a Suzue hub? Unicycle.com used to carry them, but doesn’t appear to anymore.
I think that’s a standard cotterless hub, 17 x 40. Just take the wheel out and look at the bearing #. If it says 6203rs (rubber seal) , that’s it. You can find them everywhere, any bearing supplier would have them in stock. One of the most common bearings on earth, unlike some uni only sizes.
If the number on the bearing is different, I would measure it with a caliper and go from there, or try any number you find at the site above.
The 40mm outside sounds right. Can’t confirm the other dimensions though, at least not until I get home…
An additional supplier is www.mcmaster.com
Be sure to get double sealed (both sides). You might consider the extra cost of the permanent lube ones. If they are filled with grease they will reject water and sweat easier. Temperature changes will generate less condensate on the inside.
It’s not rubber sealed and doesn’t appear to have a number on it, which is why I asked.
Hmm, maybe the number is on the other side. I bet John Foss will just give you the number soon. I don’t use my calipers often, it is a cheap tool that answers questions of size instantly.
You should have 2rs (2 rubber seals) bearings installed. That must be a bodged repair. The no seal bearings are sold to be used inside of engines, not on unis.
I have a caliper that looks almost the same as that, only it’s plastic. And the major measurements are in tenths of an inch. Fortunately there’s a metric scale on there as an afterthought…
I found what I believe to be a Miyata replacement bearing (same dimensions). Please note that it’s probably been sitting in the little ziplock bag I found it in for at least 20 years, but I don’t think Miyata has changed their bearings over the lifetime of the product that I know of. It’s 40mm OD, 17mm ID and 12mm thick.
a 6203rs
It will say it somewhere on the side of the bearing. It would be difficult to find a town in the USA that had a parts store that didn’t have them in stock.
Just be sure to only tap it in place on the inner race(center part of bearing). Lot’s of folks use a tube that just fits over the axle to tap the bearing on.
The bearings are completely stock. The seals are metal, not rubber. Thanks, John, I’ll look for 40x17.
I do have a caliper but it doesn’t have metric markings, and I’d hate to be 1mm off on a press-fit part.
Even 1/10 of a mm would be too much for the inner size. Those Miyata bearings go on TIGHT! I use an old piece of PVC pipe that’s slightly larger than the axle, then beat it carefully with a mallet. A lot.
That would be a 6203zz , for metal shields. These are used on machine tools, where debris, metal chips etc. might cut a rubber seal. I am surprised to see it as a stock choice on a uni. Pretty much all unis come with a 2rs bearing. 6203 2rs will be more waterproof than the zz. There is also a 1rs that is used stock on many motorcycles. What penny pinchers ! They don’t want to pay for the seal on the side of the bearing that faces the inside(dry unexposed) side of the hub.
This summer I had to replace the bearings in my 3hp edger. I thought they looked familiar. After opening the uni toolbox and pulling an old set out, sure enough, an exact match.
A lawn mower shop is likely to have them.
I wound up ordering from VXB, who I’ve used before. One of those “two bearings are $10, 10 bearings are $15” kinda deals. Thanks for the help.
These will fit
And if you need to pedal in bursts of 17,000 rpm , they are much safer.