The Pirellli MT66 Route tire seems to get positive reviews. There are better tires, but I haven't seen any really negative comments on it. The consensus seems to be they are far better than the stock Dunlops, anyway. Pirrelli sells the MT66 in the stock sizes of my 900 Custom (80/90-21) and (180/70-15). They also sell a 170/80-15. Has anyone tryed the 170/80-15 MT66 rear tire? I assume that would lower RPM's and make a correction for the speedo error we all know about. I know others have done this with other brand tires, but haven't heard of it with the MT66. If so, are there any issues like modification to make them fit? I'm really fine with the stock sizes, but the fact that the speedo has always been off has always buged me. I need new rubber and if I can correct the speedo by just buying a different size tire, I'd want to do it. Not to mention the 170/80-15 is a little cheaper. Oh, I did just mention it.