I used 1" ( 25mm ) medium density upholstery foam and covered it with vinyl , to date they has lasted up to 3 years of use , the firmer foam works
As soon as you introduce guide wheels and tubes for the chain it'll get noisy
Wondering if anyone has come up with a professional looking bracket to mount a mesh sling style seat to the warrior trike frame. Possibly even an adjustable
I can easily make a freewheel diff instead if it turns out to not work well.