I thought it might be mono vs paralever but the parts catalog shows:

Type A: K100RT/LT/RS and K1100LT

Type B: K100 and K75/C/S/RT

So it looks more related to weight.

I am surprised the K1100 and K100RT are listed as same because K100RT is Monolever and K1100 Paralever and as far as I know its a different offset from Monolever.

Just my 2c worth....

I don't no why the parts catalogue states that, as there is an offset between these rims although the offset is only minimal.
The A type rim as far as I know only ever came out as original on the K1100lt and the B type rim on the K75s from 1992.
I have both these rims and they are both 3" x 17 rims, I just measured the off set at 6mm. So the A type rim sits 6mm off track to the left when fitted to a monolever.
I run the B type rims on my 86 monolever rs with radial tyres, Avon storm ultra 150x70 rear 110x80
 front. I do have the K1100 centre stand fitted.


I measured the difference in the offset between both rims here.