The rubber-mounted bars on my K1100RS (converted to "C" bars) just don't cut it for me. This modification just stiffens them up so that they are *almost* rigid, enough so that they might as well be. Can you say "K1100" and "flickability" in the same breath? Actually, the bars remain rubber-mounted and there is still just a little flex, but handling is greatly improved. So for all practical purposes, they might as well be rigid. With this modification, there is slightly more vibration in the grip, but in the few miles I've ridden with it so far, it's not objectionable, but it's too soon to be sure. Vibration will probably vary with the state of engine tune and accumulated mileage. The modification is completely reversible if you don't like the result. But you probably will.
What we're gonna do is use some bronze thrust washers to compress the original rubber pieces into a smaller space than before and allow them much less room to flex as the bars torque due to rider input and cornering forces.
In the nuts and bolts section of your favorite hardware store, get 2 bronze thrust washers, 1" O.D x 5/8" I.D. X 1/8" (approx.) thick. That's all you need. Using thrust washers is neat because they're bronze, so they won't corrode, and you can specify both the O.D. and the I.D. A 9/16" I.D. *might* work, although the hole might be too small, as discussed below; I didn't disassemble things enough to make sure, and the larger hole is not detrimental. If you'd *like* to have a little flex, just use thinner washers. Or if you can't get the specified thickness, you can stack up thinner washers. My cost was 2.38 plus tax for the recommended size. Now to the actual conversion. Five steps, as follows: