Boring old farts time! Come back with me to half way through the last
century.
Older books on cycling always refer to assembling bearings using grease
but after that lubricating them with oil. Some cycle components were made in
such a way that oil was carried to the bearing surfaces by an oilway or a
spiral groove. However, pre-war books refer to thick oil and recommend
warming it first to make it more liquid. The old Castrol D gearbox oil for
cars was so thick that in freezing weather it would not come out of the can!
I don't think they could mean that. I assume that the oils for bicycle hubs
might have been something like SAE30 to SAE50. I wonder if Castrol R would
have worked. It is thickish and unbelievably sticky. Its boundary layer is
wonderfully tenacious.
A recommendation for bottom brackets was to flush out frequently with
paraffin and to pump through a thick grade of oil and vaseline. I doubt if
the paraffin was a good idea but perhaps if you flush it right out with the
clean oil/petroleum jelly mixture, it would be okay.
Post-war advice is usually to assemble bearings with grease but
thereafter to use oil. It was sometimes suggested in print that you should
wipe the outside of head bearings clean and feed a lot of oil in to flush out
old grease and dirt which implies a thin oil. As a schoolboy in the fifties,
I always had time to take the bearings apart every few weeks to put in new
grease. That still seems reasonable. The exception is the Sturmey Archer hub
gear as the pawls will stick if you use anything other than a thin oil.
If you are after the ultimate performance and minimum friction, there
are some very clever modern products. I wonder if anyone has tested to find
what percentage gain they would provide. Does anyone still use a drip feed
chain oiler?
Stuart Tallack on the Costa Geriatrica of Southern England