Commando clutch bearing

C2 bearings have a smaller radial clearance than normal, 0.000mm to 0.010mm. C3 bearings have a larger radial clearance 0.013mm to 0.028mm. Normal clearance bearing is 0.005mm to 0.020mm. Bearing choice depends on the degree of interference between shaft and inner race and housing and outer race. Why do you want to run the chaincase dry?

As I mentioned, it depends on the degree of interference fit between the bearing and shaft/housing. The bearing clearances will reduce due to interference. Too much interference, or not enough clearance means the bearing will have zero or minus clearance i.e interference between rollers and races which will lead to premature failure. I wouldn't use either a C2 or C3. Go for a normal clearance bearing.

I agree clutch slip is a pain due to oil contaminated plates but it only takes a clean every few thousand miles to fix. Running chain dry, I think, will lead to greater wear/maintenance and expense.

This bearing is a "deep groove" ball bearing not just a standard ball bearing. plenty of belt drive users fit these in sealed form. Fix the clutch slip and chaincase leak properly. If your chain lets go because you choose not to lubricate it, you will be the first to know.

Two years ago at the national rally in Devon a member's Dominator siezed it's alternator and spat him off on a busy main road. He was lucky to get away with minor injuries, the bike was spoilt and so was the following car.

How about running your gearbox empty so the oil in it will not seep into the clutch. A much quicker method of dealing with your problem.

The normal or standard bearings are deep groove.

Judging by the residue on the inside of the primary chaincase and smell, there was insufficient clearance, not lack of lubrication, between the alternator stator and rotor which overheated and locked the engine and back wheel, causing the rider to lose control and crash. We're only talking a few thousandths of an inch difference between a bike running well and an accident waiting to happen.

Running a dry primary chain has been mentioned on various threads. I will simply re-iterate this. Domi 99, chain dipped in Linklyfe. A fast run from Edinburgh to Bristol and back. Several rollers split, chain completely ruined. OK, it was a single roller chain unlike the triplex in a Commando but the principle carries over.

I agree Gordon, I do not advocate running a primary chain dry, especially when the manufacturer has provided a chaincase oil bath.

Why not use oil designed for wet mulitplate clutches ie Honda stuff, or the equivalent - problem solved.

If it still slips look to the clutch centre for grooving.

You could be a real cheapo and use 10-30 tractor universal oil available from your local agricultural store. No friction modifiers so very suitable for primary chaincases. Why no friction modifiers? It's also used in tractor oil-filled brakes. Strange concept but it works.