Continuing Saga of Clutch Sprocket Bearing

Talked to Fred at OB today. His reasoning is similar reasoning to the crankshaft bearings. There is flex in the main shaft, so he uses a C3 to allow the flexing. I mentioned that the manual calls for the 'one dot' or C2 and all he would say is he has been using these bearings and has had no problems, even in his race bikes and belt drives. He does read the forum, so he was familiar with my issue. I'll take my primary apart and see what I have, but it's a '69 and the C2 spec didn't come out until the 70 manual as far as I can tell.

What do I know? I do know it's impossible to find a 6007 C2 in any of the auto stores here and they can't locate it. Looked online and nothing there either, but the 6007 C3 bearing is typically used in electric motors.

I wonder what Hemmings sells? Anyone got one, or how about one of you Islanders call him so I don't have a big phone bill. All I see in his catalogue is 060750.

Dave
69S

DogT said:

I'll take my primary apart and see what I have, but it's a '69 and the C2 spec didn't come out until the 70 manual as far as I can tell.

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It's not really surpirising that it isn't mentioned before the '70 manual as there's very little actual technical data included in the '68-'69 manual - however the clutch bearing part number (060750) remained unchanged for all Commandos.

DogT said:

Talked to Fred at OB today. His reasoning is similar reasoning to the crankshaft bearings. There is flex in the main shaft, so he uses a C3 to allow the flexing.

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I'm not sure I follow the logic, there doesn't seem to be any parallel between main bearings that are held rigid in the crankcase and a clutch assembly which rotates at the end of the mainshaft?

I think the bearing you are talking about is the one in the clutch hub. If so you should realize that that bearing only turns when the clutch is released. Most of the time the bearing doesn't do much at all. It probably wouldn't make any difference if it was worn out or if it is a bit tight

Hi Dave,
a new c3 bearing beats a damaged c2 bearing any day in my book.
As I mentioned previously, not a showstopper.
I dunno why it need to be sealed though, self replenishing oil is a better lubricant.
The correct bearing is available from A/N as far as I know and didn't your supplier have one from them?
No sense losing sleep either way.
All the best.

In view of the fact Norton Dominators (and Manxes), not to mention all Triumph 650/750 twins rely on loose rollers to run the clutch basket on when the clutch is pulled, the Commando solution is lightyears ahead anyway. These pre-Commando/Triumph rollers are sort of clamped between clutch basket and clutch hub/centre, but give nowhere near the guidance even the most clapped-out ball bearing gives.

Get sealed to keep friction plate grit out and constant lube in as there shouldn't be much if any oil splash on this bearing in action or police would follow your oil trail to where you got stuck d/t oil fouled clutch not gripping anymore. I'd bet the normal clearance C2 gets beat to C3 clearance pretty quick in a Cdo primary.

I shouldn't have started this thread, should have kept with the other clutch bearing one. Anyhow, if ZDF is going to check the factory parts tomorrow, I'd be interested in what they use. Fred told me he uses the C3 in his belt drives, plus it's sealed.

Dave
69S