Sealed Ball Bearing question

My question is not Norton but close enough for me to ask on this list I hope: For crankshaft ball bearing
SKF 6209 I want to use a sealed bearing as I have a BNR belt drive. SKF make a 2rs1 bearing
but it is only good to 195 degrees F. They make a higher temperature rated 2rs2 which goes
to 300F or nearly so. Naturally I want a C3 clearance and I see that many higher heat range
sealed bearings are C5.
The problem is that they are only rated to spin at 5200rpm which falls a bit short of my
red line which is 6000.
The bearing doesnt have to be a SKF of course. Am I just asking for too much or does
one of the boffins aboard have some guidance for me here?

I dont think a sealed bearing to keep the oil in , in this application is a good idea.
boffin No.1

Why? Remember Im removing the inner seal, that is the crank side seal.
I value boffin opinions I just wish to know your reasoning.

If you are taking one of the rubber seals out, why not just get a 1rs (rs = rubber seal) bearing?

rubber sealed bearings are to keep grease in and dust and maybe water out.
the rubber coated steel disc seals are not retained in the bearing very firmly, with the inner seal removed its likely
that crankcase pressure will dislodge the seal from the bearing.

I don't think I would try to run a bearing with a seal there -even if you could find a sealed bearing with a high enough load and temperature rating to last.

If you still have a leak there then something is wrong..... Jim

The problem is finding a bearing that will take the rpm. Heat isnt a problem with Viton seal.
Pressure in the crankcase should be very low as Ill have a flapper breather valve on it.
On my commando Ive never completely solved the weeping DS bearing problem even with the breather.

Appreciate all your input, suppose it really is a case of better safe than sorry.

I fit a lot of sealed bearings to wheels, sometimes just by tapping the bearing (outer race) the seal will pop off.
it wont take much pressure at all for the seal to come adrift, I strongly advise not to do this , but its up to you.