Who's bike and what setup?

On your bike . . . Is that a gate post hinge strap for the seat to seat post link? I thought at first it was a leaf spring.

I have used a stem for a seat post in the past. It will lay the seat down and back and stays somewhat hidden by the seat.

I don't believe in limiting the usefulness of something to the original reason it came into being.

Ted

wow it would be cool it get a spring like that only in a < shape so the seat would stay in the same place.

Wonder how long those belts last?

I can see (somewhere in amongst the little black holes in my head) The roller shaft at an angle to give the belt a little clearance where the belt crosses itself.

Hold a rubber band on the pointing fingers of your hand, twisted like the belt in the third (best view) pic. Now point one finger down slightly. Notice how the clearance opens up the further you point your finger down?

With the far end of the roller shaft (third pic) pointed up a smidgen you will get much longer belt life.

What did you say? Drive roller/tire wear increases? Oh . . .just put a cone shaped drive roller on. One of you young whipper snapper trigonometry geniuses help me out on the angles. Make the cone the same angles as the roller shaft angle? Or half? Double?

You might be able to pull this off without a noticeable (to the non-builder) roller drive angle. You could even split the angle - half on the engine mount and half on the roller drive.

Or is it all done on the engine mount leaving the roller drive square to the tire?

I haven't seen a twisted belt roller drive in the flesh.

Feedback?

Ted