BJB, I just got home from a 90 minute ride. The tank grips seem to help BUT only if you remember to keep your legs pulled to the tank (my knees tend to naturally splay out a bit so I have to conciously grip the tank).. I'm going to be interested to see if my adductor muscles get sore later, they were getting noticeable as I was trying to grip the tank with my legs (until I'd forget). So I think the grips are a "yes they seem to work as advertised, but they seem expensive for what they are" proposition. Maybe if they go on a track bike there'd be a larger payoff.