Sealed Clutch basket bearing versus unsealed

When I got my 1973 bike, the clutch basket 6007 bearing was open both sides.
It was suggested better to put in a sealed both sides bearing 6007RS. One reason being that the seals mean less
primary case fluid getting past the bearing into the clutch pates area. And thus less chance of oiled up sticking plates.

I took my clutch part recently and found that the sealed both sides bearing was leaking grease out between the seal where it meets the outer race.
The two rubber seals were in place but were completely rotating free. They should be held by the outer race, but were spinning inside the outer race.
Maybe they had shrunk or something but they visibly leaking grease.

So I like the idea of a bearing that stops fluid getting into the clutch plate area so I thought I could one of do two things.

1) Take one seal off the existing bearing and have the one seal remaining positioned closest to the clutch basket discs so the open bearing side gets lubricated from the inner primary chain case side yet the single seal on the inside stops oil passing through to clutch discs.

2) Get a new 6007 bearing, sealed both sides of better quality. Or even take the seals off old bearing, clean it, re-grease it, put back degreased old seals and then apply a little Permatex Right Stuff externally where the seals meet the outer race that covers the space between the two.

Love to get your thoughts

Thanks

Dennis

Greased bearing will over time the grease will lose its strength and run like oil, so always good to service sealed bearings around the 40k miles mark same as sealed wheel bearings. its all about maintenance but because they are sealed they still need regreasing over time if you want long life out of any bearings.
Bearings run hot spinning so grease over time does melt down to oil or goes hard and not do its job, same with oil splashing around gets old and dirty why we do oil changes regularly.

Ashley

Do you run with a sled or unsealed bearing??

Thanks
Dennis

Sealed is OK, but unsealed unlikely to really be an issue. But, this is a lot of thinking for a cheap bearing....change it.

Thanks to both of you!
Dennis

Remember that the manual calls for a one dot (C2) tighter than normal clearance clutch bearing.

Making sure its C2 is a lot more important that seal or no seal unless you have a belt drive.

From British classic motorcycle parts suppliers here in Canada:
The first sealed bearing I bought just says 6007RS on it with no other markings.
The new unsealed bearing I just got has no markings at all on it. Its dimensions are correct though.
Dennis

The default for bearing with no clearance marking is that they are CN, N for normal. Some manufacturers will not bother marking CN but they will mark if its not CN. I would only fit a bearing marked C2.

The trouble is parts suppliers don't always know what one dot refers to or even that the manual specifies a one dot bearing.

kommando said:

Making sure its C2 is a lot more important that seal or no seal unless you have a belt drive.

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Agreed, good reminder, I had forgotten about clearance.

I remember discussing the clutch 'wobble' on the belt drive Norman White made for me. He said 'worry about it when it doesn't wobble!'

That'll be the extra bearing clearance then!

SteveA said:

That'll be the extra bearing clearance then!

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No, C2 is less clearance, its fitted to reduce the wobble but as there has to be some clearance it will still wobble. This is from NSK, note they leave CN off the 6210 when its normal clearance as its the default clearance and marking is optional.

DennisMo said:

Do you run with a sled or unsealed bearing??

Thanks
Dennis

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I run a sealed bearing the same one for over 35 years but it gets repacked with grease at major maintenance on the clutch, depends on how many miles I clock up, to me its not a hard job, I only run with between 5floz to 7floz in my primary case using ATF oil, just enough oil to splash on the primary chain to keep it lubed, I also don't over fill my GB oil so have never had GB oil migrate into the primary or clutch.

Ashley