- Single row ball bearing. Fitted to all pushrod and sidevalve engines (from 1930's to late 1950's). These are original high quality RHP bearings (plastic sealed), in the correct C3 fit - now extremely difficult to find
Update Feb 2019: Amazingly, these single row ball bearings in the correct 'looser' C3 fit from top manufacturer RHP seem to be now more difficult to find than the same corresponding SOHC main bearings!
I have managed to obtain a small batch of these bearings - but they are possibly the last ones that will be available and I only have a few left. Sorry, but the price reflects this - the bearing stockists are aware they are holding the last ones. Never the less, if you want the correct ball bearing, from top manufacturer RHP and in correct looser C3 fit - these are them.
It is worth noting that we also have a few of the same bearing from RHP, but in 'standard' fit - this is Item 0733. This is exactly the same high quality bearing, but it is not quite as 'loose' when new as the C3 fit. This just means you need to be a little bit more careful when running the bike in, to let them wear in first - so to avoid the bearing spinning in the crankcase bearing housing. If you think you have a crankcase where the bearing may have previously spun in the housing (and the alloy bearing housing looks slightly grey or worn) - then I would advise paying the extra money and going for the C3 fit listed here - while they are still available.
Final point on ball and roller main bearings fitted to 1930's/50's OHV and SV engines: Unusually, Norton's showed a roller bearing being fitted on both sides of the crankcases on OHV/SV engines (i.e. 1948 catalog), with a ball bearing fitted just on the outer drive side. However, I have stripped OHV engines down in the past where a ball bearing is fitted both sides, with just the drive side inner being a roller bearing. Not sure if it makes a great deal of difference - as like the SOHC engine, the OHV/SV engine was locked to the timing side bearing - but worth noting if you are struggling to find two roller bearings