Hello !
With such an installation...
Why not only spray chain lubricant from time to time ?
1960 B33
;)
If you have the chain-case, you could drill a small hole in it, to squirt in the chain grease. Would save having to undo all them screws. :) :)
Hi,
Don't forget the cooling effect of the oil. The primary can get quite hot and the oil splashing about and running down the case will help with cooling. The roller bearings in the centre do not need much but some does find its way there and even the clutch plate tabs and slots will get some lubrication from the mist that will be in there. Totally dry and things start to wear quite quickly.
Dave.
I can't see that the small amount of oil in a primary chaincase can actually do much in the way of cooling.
How will you keep the clutch centre bearing and rod lubricated? Also the plates against the centre and cage? It all rattles around quite a bit and its a "semi-dry" clutch not a dry clutch. The oil bath for the chain means the primary chains last many times longer than the rear ones.
That's more down to the enclosed nature of the chain's running environment. No dust, grit, salt spray etc.
The whole area is oily particularly from the engine's main bearing, so within reason, it's not going to run dry. The clutch etc should be greased on assembly so should be OK for many miles.
i would be more worried about the gap between the stator and rotor closing up and seizing without oil cooling.
the risk of a seized rotor is a bent crank, unless you keep to the 20 MPH zones.
Also, the risk of a snapped primary chain could be an expensive repair. i think primary oil goes brown over time due to water ingress.
Not an issue I've ever come across before. The stator isn't a solid lump that going to expand by 8-10 thou radially through heat.
Hi,
Why did BSA and many other makers put oil in the primary case?
Dave.
Probably because bikes were usually used as high-mileage commuters, and so adding some oil would be better for longevity than not having any.
100 miles on an occasional sunny Sunday doesn't compare.
its very difficult to achieve a perfect gap between rotor and stator and the higher you rev the more the crank will flex. However, it will be interesting to know the results, good or bad,if you decide to put on some miles without any oil in the primary chaincase.Maybe we are overcautious.
The question is which is cooler. Oil lubrication in a closed case with no air flow ( pretty damn hot) or an un oiled primary with a constant air flow? O ring chains require no lube!
Its worked for 66 years with oil which shows the wisdom of the BSA designers. Will it last another 60 without it? I very much doubt it and nothing would persuade me to leave the oil out of my BSA or Matchless (yes the one with the pressed metal case and impossible rubber seal). I also drive an 1970 Land Rover with oil lubricated wheel bearings. Its fashionable in some quarters to replace this with grease. Do they leak when oil filled?, yes, do they last forever?, yes, does the leaked oil act as a rust preventer?, yes.
I have a few pre 1930's bikes that have a primary chain guard.. open to the atmosphere at the rear. Obviously they have lasted 100 years with just an occasional squirt with the oil-can.
Remember the clutch is rotating 3 times slower than the crankshaft.
Also the engines run a pilgrim oil drip, one drip every telegraph pole, so one squirt on the Primary and Rear Chain every month is sufficient.
Best of luck trying to seal your chain-case, without an O ring it's a task.
btw.. It's best to use sealer only on one side of the gasket, otherwise you will destroy the gasket next time you remove the case.
Thanks SCIFI.
Your writings match my thinkings ,with prewar machines installations.
I am expecting a new chain.
I will install it the old way, well pre lubricated.
Then see , hear and feel how things run.