It's not a weight to fuel ratio, it's the lips to slaps ratio that does it....:shock:Well, I could post a pic of my daughter's bike -- she's new to the 2-wheel and has a Shadow, or I could post a pic of hubby's Vulcan. Don't have a bike of my own -- too chicken to solo it. I mostly just hold down the back of the bike for the hubby -- gets better gas mileage with me on th back than when he's alone on it. I still don't understand why -- I'm pretty "weighty" so it doesn't make sense to me, lol!