Seat Cushions

This is the cushion design for the wheelchair. The hybrid cushion uses a quarter inch layer of impact gel at the base to dampen vibrations and protect against heavy impacts from landing. Above the gel is a layer of memory foam over an inch thick. The foam allows for the cushion to form to the users body increasing comfort and securing the user's position. The seat can be wrapped in a variety of materials, from nylon, to neoprene, even leather depending on the user's preference. Simple snaps quickly and securely, attach the seat to the frame for easy removal and cleaning. The cushion could be used on any type of wheelchair, and would be perfect for users suffering from constant backpain and discomfort.

Let me know what you think.

Frame Design

Here is an intial concept for the design of the wheelchairs frame. The form is relatively conservative, but implements the unique tubular shape of the Dahon bicycle frame. The use of internal butting allows for thinner wall thicknesses and increased strength. The suspension has been moved to the outside allowing for easier acces to the adjustment dials as well as the ability to implement the suspension compression levers.

This is still just the first design, so please leave any and all feedback. It is 100% open to change.

Front Casters

(Heavily) Based off of the frog leg casters, this new design specifically fits standard skateboard wheels (48-70mm). The main reason for doing this is to connect the sport to the roots from which it has been based. It allows users to the ability to customize with the fun wheel designs of skateboard companies, which are more readily available. Also, it gets extreme wheelchair users into the skate shops, exposing their sport even more.

The elastomer suspension system will dampen the vibrations from impact and allow the rider to flow smoother over any rough terrain. The new design is shorter and relocates material to make for a more durable design and aesthetic.

Impact Gel

I was able to get my hands on a pretty large sample of impact gel. This soy-based gel, has recently been featured on infomercials for it's application in footwear insoles. It has also been used in hockey pads as well as saddle pads. I'm currently doing some testing to see the benefits of incorporating it into the seat cushions. Hopefully it should be able to dampen impacts even more.

Check out the infomercial here.

Frame Materials

Very detailed descriptions of a variety of materials used for bike frames. Check the website out here.

Interesting Frame Technology

I found this write up on the Dahon website. The company specializes in manufacturing folding bicycles. In order to compensate for the sacrificed stiffness of the design the company developed a new shaped frame tubing which they have tested to be stronger and stiffer than traditional oval shaped tubing. Because of the importance of percision and control, as well as the need to withstand excessive abuse, this could be a useful addition to the extreme wheelchair frame.

Follow the link here

Pumping the Suspension

Another concept aimed at allowing the rider to generate speed. The ability to pump and gain momentum is fundemental in all extreme sports. This concept would allow the rider to compress the suspension while riding to manipulate their speed on the ramps. The lever connects to the base of the strut assembly and pivots off the top wheelchairs frame. As the lever is pushed forward, the force is amplified and compresses the spring and strut. This pulls the frame and the rider lower, shifting the weight downwards. When done on the ramps this weight shift will increase the riders momentum and allow for a burst of speed. The levers handle would be designed to sit lower than the seating side plates so there is no obstruction to the user.