STEP 2: Assemble seat
4.Loosen the nut and washer on the seat (13), use N tool and fix on
the sliding (16).
5.Loosen the knob(20),washer (19), bushing(17), screw(84) that
on the sliding, then insert seat into the seat post (21).
6.Screw(84), bushing(17), washer (19) and knob (20) fix on the
sliding(16).