SKF #63004-2RS1 C3
(20 id x 42 od x 16mm width)

check the post "started looking at my Paso project bike" on page 6 somewhere in the middle.
Sorry, but the computer in this internet cafe does not permit any copying so I cannot paste the link here.

G.

check the clearance in the bearing that you buy matches the clearance that you remove.
this should be marked on the side of the bearing near the part no. as C1, C2 or C3.
It should be OK but just make sure...

Precision bearings have tighter clearance but don't handle high revolutions well - they can generate more heat.
sealed bearings have a fairly small amount of lubricant available to the rollers - but should be ok for the relatively low RPM speeds on a motorcycle.

most likely they will be C3 clearance for 2RS [rubber seals] type bearings.