This is the second failure that I have had of the drive side rear wheel bearing. It had plenty of grease both times so lack of lube didn't cause it. I have a set of RAD Mfg. SM 17" wheels on it with 15/38 gearing. The bike has a 436cc big bore, with hot cams, porting, 39 FCR, 3x3 so it isn't lacking for power. Since it has been the drive side both times could it be the extra power causing the failure? Has anyone else had this type of failure. What is the concensus? What do you all think is the cause?

how tite do you run your chain ???

is the hub dameged enef to let the bearing wiggel in the housing ???

I do not run the chain tight at all, put on the SM chain buffer for that reason, and the bearing is so tight I have to cut the outer race to get it out. Here are pictures of the way I removed the outer race when the inner race falls out & you cannot get to any part of the outer race to drive it out.

First I cut 2 grooves in it almost completely through the race about 1" apart.

Then with a punch and a medium ball peen hammar I cautiously beat on the outer race between the 2 grooves/slits I cut to break the cut section out.

Here is the results.

Weird.....you can't access the inside lip of the outer race from the opposite side of the hub?

Did you lightly grease the bearing before install? What brand of bearing? I have found that the cheap bearings only last about a season...how many miles?

There's an easier way. Weld a bead around the inside of the bearing race. When everything cools the race will fall right out.

If you look at the second picture you can see the inner bore, the paper towel is in the bore, on the RAD MFG hub is a lot smaller that the outer race. I have a welder but not enough confidence in my welding ability to try it I am fearfull I will mess up the hub.

is there only one bearing on the drive side? most hubs double up on the bearings on the drive side.
oem drz hub & talon included.

at least it's only a bearing. since it's failed twice, you may be able to get an idea of how many miles it lasts & keep replacing it before it fails completely to prevent a potential lock up situation.

where do you buy the replacement races and bearings?

My suggestion is to take a known good bearing to a bearing supply house and get double sealed bearings because I'll bet the OEM ones are single sealed units. Like was said by Iowa how tight is the chain? Too tight will strain the chain, sprokets, and hub.

RAD MFG supplied me with the part numbers for the seal & bearings. SKF 6205 cages ball bearing. Seal is a 52mm od x 35mm id x 7mm thick. I can get them from a local bearing house. Have to get the spacers from RAD or send out to a machine shop to have made. Spacers are aluminum & get grooved where the lip seal rides from riding on it while the bearing is failing. Only one bearing per side front & rear.