What do you recommend to keep from sliding foward into the tank?
Is there a good solution or product other than buying an aftermarket Sargent or Corbin seat?

 

It's pretty involved, but you can modify the foam in your old seat... that's only really a solution if you've got some time to spare though, and you probably will still need to invest in some foam and vinyl.

TecSpec makes a tank gripper pad that you can add... haven't tried it but I imagine it would help (also not a super cheap solution)

Or do some thigh workouts...

 

Just got a bagster tank cover it's fully padded and love it. But very spendy at $208 there is a yellow one on eBay for about $100. Pic in my album

 

Look at snowboard stomp pads. Lots of designs. Put one on each side of tank and you will have all the tank grip you will ever need.

 

stomp grip, i cant ride without it

 

I never thought about that, that's genius!