This is the single row ball bearing. Fitted to all upright and Norton laydown gearbox's mainshafts on the non-drive side (i.e. behind the worm mechanism for the clutch rod. It was also used again on Manx models (i.e. without kickstart provision, on the layshaft bearing - again on the cover side (i.e. the Manx gearbox cover had two of these bearings fitted)
This is for a high quality RHP brand bearing - the best quality bearing available and derivative company of the original manufacturer supplying Norton in period.
Dec 2021 update: As with all imperial RHP bearings required for Norton single models - these bearings are now getting very hard to find and prices have risen exponentially in the last 5 years. Covid has made bearing manufacture difficult and - prices are rising even more sharply. We are sourcing another batch, which should be available early Feb 2022 - but price shown is only indicative at the moment - if you order, note we will confirm final price when they come in