In the early days he had a Thunderbucker in the neck position. But nowadays Rickenbacker makes very decent Humbuckers (HB-1) and that is what they installed in Lemmy's signature Rickenbacker.

I once read Geddy Lee from Rush stopped playing Ricks because it became painful for his arm or hand. In an interview he said he might give them another try in the future (or during the last tour).

Not 100% sure but think Lemmy was using one his rickenbackers for Newcastle sound check. The photo on twitter was a bit small to be sure.

https://twitter.com/myMotorhead/status/266581214813638657/photo/1
Looks like it's a Rickenbacker to me.

Yes its his Signature Ric.

as far as I know he only used it for this gig, it did look weird but didnt sound particularly different. Yes i saw the headstock of a Rick behind the amps too.
I remember we went to Graz to see them and the gig got cancelled right at the last minute coz Lem was ill, There was a studio upstairs at the venue and Phil and Mikkey recorded the backing track for The Game instead. Phil played the bass and tried playing the Rick and hated it, so borrowed a Fender from the support band.