roller bearing

how do theymake steel ball bearings so perfectly round and of the same size?

1       A ball bearing company uses precision machinary for maintaining limits and tolerences specified as per the standards.
For that they are using precision lathe for turning of the pipes initially,cylindrical grinding m/c for the rough finished surfaces,honing machines, lapping machines for . . . → Read More: how do theymake steel ball bearings so perfectly round and of the same size?

Are my skateboard wheels too small for my bearings? well to start off i just bought some brand new spitfire 54mm wheels. but when i try to put the reds bearings in they wont fit. what should i do?

1       No, they aren’t too small. The problem is you’re trying to push the bearing into . . . → Read More: are my skateboard wheels too small for my bearings?

I’ve got a 2001 redline petty cash. i don’t know what size bearings it needs. i read about the bike on-line and it says that the crank is 175mm, i think that’s just the length though. so i measured the hole where the bearings go and it was 5 1/2 cm.

1       crank length means nothing to . . . → Read More: How do i tell what size bearing i need for my bmx crank?

I thinks the bearings are gone is this something I can do myself (I’m a millwright mechanic with an engineering degree) The bike is a Trek fuel about 4 years old the main crank is a shimano. Thanks

1       Yes you can but you have to buy a crank extractor but in your case you can just . . . → Read More: I need to change my bearing hub on my mountain bike?

I had the front wheel off today and the bearing is completely frozen. It was stiff before and now won’t move at all.

The thing is that I can’t feel the stiff bearing at all when riding the bike. Is it safe to ride the bike (gsxr 750) for 2-3 weeks with the bearings in this kind . . . → Read More: Frozen wheel bearings?