I'm on overload trying to determine what cafe bars to buy for my '71 R75/5 SWB bike with a police tank. The BMW dealer recommends their 600mm (23.6 x 3.5) bars. I've also been looking at a magura bar that's 25.75 x 2.25; and then there's the fehling eurobend (not S) that's 26 x 2.5. All have slightly different rises and lengths. I currently have the orig. US bars (27.5 x 5.5) on the bike and want something lower and more aggressive that won't kill my 53 year old back. Any quidance would be appreciated.