Scooterotica

The series 2 has only done just under 200 miles and the rear hub oil seal has gone, bloody Indians cowboys more like

Whats the best oil seals to go for

Rolf seals are reputed to be fine.
but a rear seal going can often be a symptom of something else amiss, like the rear bearing...
I had oil on the rear shoes, and just changed the seal, this lasted 1000 miles, then i changed it again, which only lasted 500 miles, so bit the bullet yesterday and stripped the gearbox down. yep the rear bearing was well worn.
casa one, had done about 5500 miles before the first oil leak.
So check any play on the layshaft while you're there, maybe change the seal and hope that that's it, but be prepared to do it, and more, again...
of course, it might just be the seal, and you're laffin'

Am I right in thinking that a failing/failed 'O' ring on the layshaft also causes these oil leaks.

Oil was leaking 'around' my rear hub bearing, so changing the seal had no effect. I made up a paper gasket and gunked it in with blue gasket goo. That sealed the leak though, fingers crossed and cured the problem. Your right though, bloody indian engineering. Its Poop!