radial bearings

[tvrc18]

Is there a right way or wrong way to fit the wheel bearings in a hub? Do the numbers on the bearing face out or in or does it make any difference? On an off brand that uses radial bearings on the crank does it matter? I am helping a friend rebuild a Japanese bike and he ask me this and I could give him an honest answer.
Terry

[t20sl]

On wheel bearings it doesn't make a difference which way the writing goes.  I always put the writing to the outside so that when its time to get new bearings I don't have to remove them to see their size to purchase new ones at a shop.
As far as crank bearings I have run into times where the manual specifies which way to install the bearing.  On Hondas occasionaly I have noticed a larger radius on the inner race on one side.  Generaly this goes against the crank due to a large radius where the shaft flywheel junction is.  
More important and often over looked is the ratings of the bearings.  Not all 6305 are the same.  There are differences in the press fit on the shaft and tolerances of the running clearences of the bearing itself.  Unless you match the brand and all the numbers, play it safe and buy the bearing from the engine manufacturer.  Bearing house often "substitute" with no real knowledge of your application requirements.

Ted

[dirtbike]

You can mount the wheel bearings as you please. As for crank bearings. I can well imagine that Honda could have a special bearing with a larger radius. I have never see it myself but they seem to be keen on inventing their own bearings instead of standard dimensions.

Bearings with special tolerances on the outside or inside diameter are rare and very expensive. The internal clearance is the most important issue. Normally it should be C3 or C4. Some codes specify which type of cage: brass, steel or polyamide (plastic). For example a 6305 C3 could have any cage material. You can safely use either one. Many people preffer plastic cages due to the lower friction, seemingly less wear and less damage in case of failure. Others like a metal cage better since it's more rigid and offers a better resistance against heat, deterioration due to gas and aging. Bikes have cages of both metal and polyamide and everything seem to be working just fine.

In my opinion, japanese bearings such as NTN, KOYO, INA, KOYOTO or NSK are the best. They aren't cheap though.