None of my bearing books "SKF & FAG" list a 62304 bearing.
the ones I find on line state they are a single row deep
groove ball race...
With a bit more searching I found this.. looks like FAG
do a double row in the right size...
http://www.google.co.nz/url?sa=t&rct...79142246,d.dGY

This link has both of them! Don't think you can machine the hub to 30mm deep as there would be not much left of the spacer if anything. I did think of two thinner bearings, will investigate further or just put the 62304 in - has to be better than original.

Just found these but only a budget bearing, probably good enough for this instance.

Cheapest branded one's (FAG) that I found when I looked into doing this mod were from Germany. Even with the shipping costs, they're way cheaper than in the UK.

http://www.dswaelzlager.de/Rillenkugellager-62304-2RSR-FAG

I haven't personally done the mod yet; mainly because I want to see what difference a 525 drive kit and poly cush drive rubbers have on OE carrier bearing life.

they should be ok.... just want to pop the seals out and pack them
with a good grease...

I will go down to one of the bearing surplyers & see what I can come up with..

i have had Polyurethane cush rubbers in for well over a year...
cut them from 95A urethane sheet... just starting to get a bit of
movement in them...after maybe 8,000km ..
I think "maybe , might" a new set will last my bike a lot longer than a normal XT...The Rekluse clutch has a lot softer power delivery to the rear wheel..

For everyones' benefit,

Hunday's 62304 Bearing is NOT a double row bearing tho' it is a beefier bearing than the o/e bearing.

Double Row Bearings are SKF 4304 ATN9 or FAG 4304-B-TVH, they are, as you would expect, fairly pricy.

Edit; these bearings are open, no grease seals, so they may not be suitable for the mod

According to his OP, yes he quotes a 62304 bearing, which indeed is a single row bearing, but the problem is/was he didn't give the second part of the bearing number. The 62304 is available in a deep groove double row type, which is a 62304-2RSR (available from FAG), I'm guessing that's the bearing number Hunday probably meant to quote originally?

I think it's probably best if I amend the bearing number references in the original post to clear up any confusion.

As far as I can see, from what we know now, any of the following double row bearings will do the job:

FAG 62304-2RSR (sealed)
4304-2RS (sealed)
SKF 4304-ATN9 (open)
FAG 4304-B-TVH (open)

Thanks to Pete, Harry, Chris and everyone else for their input. It seems that we have a definitive list of bearings that WILL fit! ;)

OP now amended.

I twice send Hunday a PM, but �till today no replies.... I really like to try his urethane cushdrive rubbers.

He is a little hard to track down! ;)

Email him, rather than PM. It gets faster results.

I tried PMing him and emailing - no reply so far :-( I'd like to replace the worn rubber ones with the poly ones if possible.
BTW the budget bearing I listed is double row with seals, think I'll try that probably. And the 525 chain mod as I have a nearly new chain

Cheers. I've added that to the definitive list in the OP.

Keep trying the emails. It took me about 6 to 8 weeks to get a reply, and then a further 2 weeks to get the goods! ;)