Damn, I just wasted $10 on grips. It did not occur to me that the BMW grips would have non-standard inside diameters & I did not notice the dimensions helpfully posted with the pictures earlier. When I started to peel off the left grip I found that there is a thick plastic tube under it that probably houses the heating element and also makes the required ID of the grip the same as the throttle side. However, it seems to measure 30mm, not the 25mm posted by Embeedee with the photos. What is going on here?
Are my only choices going to be from BMW if I am keeping the stock heaters? The ProGrip Superbike grips I've used on all my bikes for years are not going to work. I'll just have to keep them for another bike, another time. My beef with the stock grips is how smooth they are; I like tacky, sticky grips that let me ride with a light grip (force applied with my hand, that kind of grip).