About half my miles have been with my girl on the back, it's just something that you have to get used to. At first it is kinda scary because the bike feels alot different with a passenger, but once they learn what to do and what not to do everything is fine. I keep the rpm's higher with her on the back, and I don't really notice anything being slower, but I'm not out racing with her on there. I'm about 210 and she's about 115, and I have the rear preload on 6 when she's on with me, a must. Braking is a little more difficult, because you have alot more weight moving forward trying to make the front end dive down. It's an easy fix though, start braking earlier. All in all it's nice having someone there with you for a nice enjoyable ride, but it's WAY more fun by yourself.