I started to read the article then just skimmed it
. I'm not sure what you point is . . Sealed bearings would prevent damage from dirt ingress and I usually fit half-sealed bearings on the output and input shafts where there is a possibility of dirt getting in from the output shaft oil seal and from the clutch mechanism.
These 'Airhead' boxes use self-aligning 'C3' bearings which have a greater running clearance than other bearings and are better able to handle rapid changes in temperature. I have never seen a 'Clean-Sealed' bearing offered in C3 standard - maybe they are on their way ??
Do you put sealed bearings into Airhead boxes - and if so, what type of bearings do you use ??
Bob.
