I have a drz400s, with 15/47 gearing on it. It came with 3x3 mod, jetting, and aftermarket pipes and a yosh muffler (which is really loud). Going down the road at an indicated 57mph (So realistically more like 52mph) is pretty much the top of the comfort zone. (rpm wise- as far as I can tell) My question is-Are other bikes equally uncomfortable at this speed, or is it just the exhaust? First gear is really low on the bike(I can idle off from a standstill on level ground, and plunk along at 5mph), so I don't think I would miss the lower gearing in the dirt except in extremely technical stuff. I could also get an exhaust insert to lesson the vibrations, which is something I should probably do anyway. Opinions?