looser bearings
2rsr means its sealed on both sides. rip out the seal on the inside of each for crank bearings! leave the outer one as a supplement to the cruddy stock crank seals.
c3.... now this is a tolerance reference. the clearance between the balls and the races.
the first tolerance, c2, ranges from no clearance to a tiny bit of clearance.
great for shafts that arent tight, and bores also a lil loose. and low temperature changes.
cn or standard bearings have a wee lil bit of clearance to just a whisker more clearance. good for a shaft that needs a bit of effort to get on the bearing, or in the bore(not both!). good for some temperature.
c3 even looser than cn. the shafts tight, the bores tight, and it gets hot.
c4 looser still for when it gets even hotter and things expand even more! and your using shrinkfits and presses to get them on!
c5 etc....
the other tolerance is the abec number and usually abec 3 or 5 is whats readily available... 1 being pretty lousy, 7(or higher?) being super expensive...
cn is standard. get a standard set of nachi bearings. anythings better than the china ones.
now if you meant the lil and big end bearings...meh. bushes are best for some, rollers for others... never had any fail....
