600lb bike, I was 160, and he was about 180... and yes, he was giving me "worst case scenario" training (leaning as far as he could while keeping himself in the seat). I was hitting the curves at their "advised" speeds as posted on the little yellow signs. (35 mph in this case). that is my whole point... the first time you take out a new passenger, you should be riding well within your safety zone. even if they tell you they've ridden with other people, until you get a feel for how they ride with you, you should be riding conservatively.