I haven't seen any backrests mentioned anywhere for the Sport, so, I decided to make a proto-type. The bike ergonomics seem to favor a slight forward lean which is appropriate for aggressive riding, and doesn't seem to warrant a backrest at all . Unfortunately, my back won't take unsupported riding all day, so I need a back rest and a modified forward shift for my butt to make that work. Of course, I didn't want to lock myself into a permanent seating position so what ever I made must be adjustable, and not require a hole in the seat.
What I built for myself is simple and reasonably comfortable. The actual backrest piece will be improved soon, it works for now and has allowed experimenting with lumbar support and position. When not in use the backrest can be flipped back out of the way, or into position in seconds, even while moving.
I used longer bolts and spacers to mount the pivot brackets to the front passenger handhold bolts and a rolling pin wrapped with foam for the cushion. The cushion doesn't spin as that would allow it to roll up your back and out of position. It dismounts with a couple of quick release pins and you can lift the seat a small amount which allows getting your sweat shirt out of storage with out removal.
The backrest pushes me forward about 1 1/2 inches, which bends my arms a little and supports my back.
What I built for myself is simple and reasonably comfortable. The actual backrest piece will be improved soon, it works for now and has allowed experimenting with lumbar support and position. When not in use the backrest can be flipped back out of the way, or into position in seconds, even while moving.
I used longer bolts and spacers to mount the pivot brackets to the front passenger handhold bolts and a rolling pin wrapped with foam for the cushion. The cushion doesn't spin as that would allow it to roll up your back and out of position. It dismounts with a couple of quick release pins and you can lift the seat a small amount which allows getting your sweat shirt out of storage with out removal.
The backrest pushes me forward about 1 1/2 inches, which bends my arms a little and supports my back.