The Outsider is my second PVC wheelchair. It is a quad design rather than a trike. Like my other recent designs it features the rectangular camber tube. PVC is a little heavier than wood. The frame weighs about 22 lbs. It is also somewhat more expensive than wood primarily due to the need to special order certain PVC fittings. Regardless, the cost is still relatively low.
 

PVC tubes have the advantage of creating a round frame without hard edges and they are weatherproof. The frame should be painted to protect it from the sun. PVC pipes are inexpensive. Therefore, replacing frame parts is cheap and easy to do. The connections can be glued or screwed per individual preference. 
 

PVC has the added advantage of some shock obsorption particularly in the seatpan. I think the Outsider makes for a useful wheelchair for outside environments where you don't want to use your primary wheelchair such as at the beach, on nature trails, road races, or for limited use in a skatepark. It can also be used as a shower chair.