I'm doing a K100 Cafe Racer Conversion. I took off the existing bars and put on new ones: http://caferacerseats.co.uk/products/104-adjustable-clip-on-handlebar - the left one fit ok but it took a lot of persuaision with a rubber hammer. The right one however would not fit and I broke the plastic around the brake/throttle assembly trying. I think the bars are very slightly bigger than the stock bars. I'm not sure but I may need to buy a new assembly. Can anyone advice what I should do here?

Most aftermarket bars are 7/8" while BMW bars are 22mm making the BMW bars slightly narrower in diameter. As a result some have had difficulty fitting the BMW switch gear in these bars without sanding down the bars or opening the perch with a dremmel or rat tail file. 

I have spare switch gear, left and right from an 85 K100RT, if you are looking for replacements, send me a PM and we can discuss price, etc.