The seat is taken directly from the Kawasaki donor bike. Like the seat back, the seat itself also has a formed plastic base. But unlike the seat back it does not have terrific mounting points. The front of the seat originally mounted via a pair of “C” shaped plastic tabs shown with the white arrows in Photo 1. The rear of the seat was held in place with a pair of plastic mounting tabs shown with the red arrows in Photo 1 Unfortunately the rear mounting tabs are not very strong and are meant only to keep the seat from moving around and not meant to be load bearing. Instead, all of the weight on the seat was originally transferred to the formed plastic which rested directly on the frame of the Kawasaki. As a result, the two plastic attachment tabs at the rear of the seat can not bear much weight.
Fortunately, there is a strong, flat area molded into the back edge of the seat (see red arrow in Photo 2). This area is strong enough to support the back end of the seat while the front of the seat will rest on the frame of the trike itself. The front “C” clips will still be used to keep the front of the seat held in place but will not be load bearing.
A support bracket at the rear of the seat is made using a length of angle iron which is bolted to the two plastic mounting tabs. Quarter inch flat stock is then used to make a mounting pad which rests on the solid flat portion of the formed plastic. The flat stock is positioned and welded to the angle iron cross piece. (Photo 3)
This is what the rear mount and seat support looks like when it is welded together and removed from the seat. (Photo 4)
With the rear bracket back on the seat, two support posts are cut from 3/4 x 3/4 rectangular tubing and bolted to the support bracket. (Photo 5)
The seat is then flipped over and the support posts are bolted to small tabs welded to the frame of the trike. (Photo 6) Additional holes can be drilled in the support post to raise or lower the rear of the seat to get a more comfortable angle if necessary.
The front of the seat is held in place using a ½” steel rod which passes through the trike frame (enclosed in a steel tube) and the two “C” clips on either side of the seat. The inside of the plastic “C” clip fits snugly against the trike frame preventing the seat from moving left of right and the clip and steel rod prevent the seat from moving upwards. (Photo 7) The rod and “C” clip act as a hinge so that the angle of the seat can be adjusted by moving the rear seat bracket up or down.
While the seat can not move forward because of the steel rod and “C” clip, it could possible collapse toward the rear of the trike if the bolts on the support posts were to loosen slightly. To prevent any rearward movement of the seat, brackets are welded to the rear seat support and the center of the trike frame and an adjustable turnbuckle is bolted to the brackets. (Photo 8)