Singlespeed & Fixed Gear - cartridge bearing compatibility

i know this has been mentioned in a thread before, but there were a few different people saying a few different things (numbers). and it sucks to get bearings and then find out they wont fit in your hub...

so im wondering, what is the best cartridge bearing that will work in the IRO/Formula rears? are the bearings that come in those a different size than other track hub cartridge bearings, or could you swap them for, say, some phil or da bearings?

i know this has been mentioned in a thread before, but there were a few different people saying a few different things (numbers). and it sucks to get bearings and then find out they wont fit in your hub...

so im wondering, what is the best cartridge bearing that will work in the IRO/Formula rears? are the bearings that come in those a different size than other track hub cartridge bearings, or could you swap them for, say, some phil or da bearings?
As long as you get them in the same size, any bearings would work. You can go to your local bearing salesman and have him hook you up. A quick check of my formula hubs reveals that they are 6000LB. Take that to the bank.

so im wondering if that's a different size than a phil or d/a bearing or other bearing that's higher quality than what comes in the formulas

Cheap good quality cartidge bearings are readily available pretty much anywhere nowadays. Formulas likley come with decent bearings in the first place, is there actually a problem with your current bearings?

If you do get bearings from the local supply place it's worth prising out the seals and checking the lube to see if you need to add some grease. The lube in a bearing intended to be sitting at the end of a motor spindle spinning at high rpm in a dry and fairly clean environment often isn't optimal on a bike. Adding some nice thick grease solves this problem.

This site sells cartridge bearings:
http://www.electricscooterparts.com/bearings.html

Get the sealed 6000 kind.

One reason people are asking about "better" bearings is that even though the stock ones are fine, this is one area where you could possibly upgrade performance for a reasonable amount of money...

Do you guys have a preference for RS(plastic seals), Z(single metal shield) or ZZ(double metal shield?

Many places have these listed for the same prices. Was just wondering if there was a rule of thumb for replacing cartridge bearings on bikes(as opposed to the motors that most of these are designed for)

In general the fewer shields/seals, the easier it will roll. But I'd guarantee that rubber/plastic shields will keep junk out better than metal. That's skateboard bearing experience talking.