Anthony I usually fill up around the 150 mark, but that is usually conservative riding, as for leaning once the foot pegs catch I think you have leaned far enough. The only way to learn is to ride it, being a lot more cautious in the rain or wet ground..
I now have the 08 speedmaster and find that the new tank I can go a little further, but will need to set my margin after the service (500) tomorrow...
