Bicycle Tutor

Hey does anyone have a good place (website) to order caged bearings? With that question in mind I do have another. How would I measure a front/rear hub that has no markings on it? Here is a small example per say I have a front wheel, as pictured below, what area would I measure? Sorry for the fuzzy picture.

I think just about any good online site will sell bearings. You may have a choice of "grades" (quality). Grade 25 is very high quality (comparable to top end Campy bearings). Grade 100 is good quality. Grades with higher number than that get into the "cheap replacement part" category. Fine for a lower end bike, but go with something a little better if the bike warrants it. I recommend using loose ball instead of cages unless you really want them. You can get one more bearing in the wheel without the cage which means the load is spread out between more bearings.

What are you trying to measure? I think most front hubs use 3/16" bearings, but there is some variation. For bearing size you measure the individual ball, not the retaining ring. But maybe you're talking about something else?

Dave,

Awesome information. The grade is something I really never knew about for Bearings. I notice that the lower the number the better. It reminds me a lesson my father taught only for bolts there is Grade 1-8 (1-cheap and 8-best) only reverse in this situation. I am gonna try using one more BB then caged, something else I did not know. Just grew up always using the caged type lol .

You said it exactly. Measuring the BB is the key huh? Not easy for me to convert millimeters to standard sizes, but I guess I can always use the net.

The ones that have variation are the ones I usually run into.

Thanks for all the info
Bill

(Nov 19, 2009 06:41 PM)DaveM Wrote:  I think just about any good online site will sell bearings. You may have a choice of "grades" (quality). Grade 25 is very high quality (comparable to top end Campy bearings). Grade 100 is good quality. Grades with higher number than that get into the "cheap replacement part" category. Fine for a lower end bike, but go with something a little better if the bike warrants it. I recommend using loose ball instead of cages unless you really want them. You can get one more bearing in the wheel without the cage which means the load is spread out between more bearings.

What are you trying to measure? I think most front hubs use 3/16" bearings, but there is some variation. For bearing size you measure the individual ball, not the retaining ring. But maybe you're talking about something else?

Well, even in countries that use metric units only, bearing balls are sold in inches, for conversions, google is your friend (try to search for e.g. "4mm in inch")... Fortunately my caliper can measure both and there are only a few standard bearing ball sizes (in bikes...). For the hub, I'd try to find specs or even explosive views on the manufacturer's home page (if you do not still have the bbs). When you cannot find them just get 3/16" and 1/4" balls, try assembling the hub dry first to see what fits best. bbs are inexpensive and when you plan on overhauling other hubs you'll probably need both sizes anyway.

I also noted that the bearing seems to be a bit pitted (in the second picture), though I cannot tell if the pitting is in the races or a bit outside of it.

Oh, and There are probably no caged bearings that fit inside hubs (or they are at least difficult to find).

@Joe I will probably just go with a new hub for that rimn. Just used it for an example. So 3/16 and 1/4 inch bb's. Lol yea another question for you, you said your caliper? Should I get one and manufacturer name?

I noticed there are different types of bb's Ceramic, Carbon Steel, Stainless Steel, and Solid Brass. Does the Grade system apply to all of those types or just the Stainless ones? Forgive me, but when my mind wanders it is like solving a mystery, GET ALL THE DETAILS I CAN.

I think carbon steel is slightly harder than stainless. So it is better for bearings unless the bike would be exposed to lots of water, salt, etc. I wouldn't bother with ceramic. Unless it is a very high end hub, you're just wasting money. Don't know about brass, but I don't think they're normally used for bikes (too soft?). Grade 100 is probably fine unless you want to get fancy and go with 25.

Fair guess that a front wheel used 3/16" bearings. If you can measure in mm, divide by 25.4 to get inches. Any hardware store will have a decent caliper for not too much. They are something you will use over the years.

If there are not pits in either the hub or axle cones (where the bearings roll) probably no reason to get a new hub. Note that to change the hub, you have to replace the spokes which is a doable, but a more complex job than rebuilding the bearings. If you pay to have it done, you probably can get a whole new wheel for the same price as a hub, labor and the spokes.

Can't tell you what the right thing to do is, but just so you know what you're in for...

That's really interesting. The Stainless ones sound more like the ones I should use. Got the grade system down fairly well and 25 should not be all that much more expensive then 100. As for the hub, yes you got it right on the guess, I am gonna rebuild it for learning process. So far I accumulated Minora Truing Stand, all the park spoke wrenches, left-handed crescent wrench (<--JOKING ON THIS LOLOL), and the rest needed except for new spokes and nipples. Do appreciate your awesome advice as always.

Oh on the note of the Carbon Bearings I do rely on my Bikes for daily transportation no matter what the weather. If wet weather does happen I try to dry off as best as I can.

Well, the problem is that moisture will get inside the bearings where you cannot dry it off. I own but do not like the truing stand, it is supposed to be "self centering" but is not... you will need a dishing gauge (which can be cut out of heavy cardboard or wood, if you want to go for the reusable version). It is shaped like that: _/^^^^\_ the lower legs are about 45cm apart, overall length is 70cm. Height from bottom of the legs to bottom of middle segment is 10 - 15cm. I use an old spoke as a measuring feeler. Do you have a wheelbuilding book? I recommend (http://www.wheelpro.co.uk/wheelbuilding/book.php). I don't know him personally, but I like the book and have successfully built about 10 wheels so far. Good luck!

The only two books I do have are Zinn and The Art of Mountain Bike Maintenance and the other Bike Repair Step-by-Step by Rob Van Der Plas. They both have sections on wheel building, but that is pretty interesting there is a book on only wheel building. Looks like another addition to my growing library will have to be done. There is another book I found floating around called, Building Bicycle Wheels by Robert Wright. Heard of it anyone?

No, but there's also the book by Jobst Brandt "The Bicycle Wheel" which is recommended by some.