How to buy a 19mm mid bb from a bearing shop?

Question

Sounds silly, but I probably need more specific dimensions than 19mm. And whta exactly does the 'mid' mean? Any special bearing type?

Thanks in advance people.

Answer 1

First, you might find that you'll actually pay more money at a bearing shop than you will with a bike shop.....and that they may have to order your bearing for you since most bike bearings aren't all that common in the industrial world that bearing shops make their living in.   I've run into this a couple of times.  Recently, hoping to find some 6804 bearings quickly, I found that one shop wanted $11 each, another wanted $13.50 each, and the third wanted $7.99.  From a bike shop, I can get them for $7.00.   Stupid problem is that NOBODY had them in stock.  lol.   :o)

So....the 19mm measurement is the inside diameter of the bearing.  When shopping you'll also need to be able to tell them the outside measurement (metric in this case) and the thickness.  And you have to be accurate....one or one-half mm's difference is a huge variation and believe it or not some bearings come in sizes that close to each other.  

If you have sealed bearings, look carefully at the rubber seal and you should see some numbers on it.  The "6804" that I mentioned above is an example.  It may have a letter or two in front or after the number.  These are standard bearing catalog numbers in the industry and if you can find the one on yours that's the best way to tell the man what you need.  Measure to double check and give him both sets of info.  If you just tell him you want a sealed cartridge bearing and tell him what it's for he can give you the right type (there may not be any other choice, though).   Bearings can get pretty technical, and manufacturers choose the best types for the application already, so just stick with what you have in there.  

If you want, you can probably order your bearings from this bike shop in Oregon....super nice people and very knowledgable.  If you don't see what you need, call them up and they'll probably get you straight.  http://www.biketoolsetc.com  

Hope this helps!   :o)

(btw, "mid" is just one of four terms used for bmx bb's.  It's just the size of the bearing (and other design aspects of the whole bb assembly).  Check out the faq's at Dan's Comp for photos and explanations of the different types.)