Quote Originally Posted by james_stan View Post
Well I never - I've bought a fair few number of o-rings for motorcycle repairs in the past and never encountered 'Shore rating'. Just bought standard nitrile rings. Every day a school day eh? So looks like meteor ring it is. Is the cylinder much smaller on a Meteor?

Cheers

Jams
I believe they are 25mm bore (I know the later Gamo type ones are 25mm), I suppose in theory O rings are only normally used for sealing things and are not really used to being shoved up and down bores at great speed and pressures (but I'm happy to be proved wrong with these sort of applications), so I'd expect a harder shore is needed in this case.

Pete