One consistent problem encountered by wheelchair users stems from the front casters. When these wheels are small, they tend to get stopped by obstacles such as cracks, potholes, cobblestones, and soft surfaces, potentially pitching the user head-over-heels to the ground. When they are large in diameter, the are likely to flutter back and forth causing the wheelchair to vibrate. In addition, they may collide with the wheelchair’s footrest as they rotate around. As a result, most wheelchairs caster wheels are a compromise mid-size.
In order to deal with rough terrain such as gravel, grass, and packed ground, having a single larger wheel mounted in front of the footrest performs well. Such a wheel is able to smoothly glide/roll over the rough terrain and still not interfere with the footrest. The ideal size of the wheel depends on the type of terrain and is variable and debatable. My preferred wheel size is as small and as close to my footrest as possible, while still working as intended. Popular commercially available wheelchair trike-wheel attachments are too large, too heavy, too far in front, and too expensive for my liking, so I decided to make my own.
The trike-wheel I am using is pneumatic and is 6.5” inches in diameter. It comes from a electric landboard. I installed this wheel into a cheap $20 steel caster frame, replacing the existing plastic wheel. In order to dampen vibrations from extra play in the swivel, I lined the ball bearing components with a mini nylon bungee cord to create a gasket of sorts.
The frame was built from scrap square aluminum tubing and bolted together for ease of construction. One of the most complicated aspects (expensive) of commercial trike-wheels is the physical connection to the wheelchair. My goal was to make this connection as simple as possible. I am using a T-shape that conforms to the front and the top of the footplate. It is held on by friction, pressure, and two mini-bungee cords. Originally, I didn’t think my connection would be robust enough to stay on. But it has worked fine despite my testing it on fairly rugged terrain.
The exact configuration of the trike frame will determine how high off the ground the wheelchair’s front casters will be raised. I wanted at least 2” of height in order to clear most terrain obstacles. Since raising the front of the wheelchair tilts my backrest into a reclining angle, I sometimes place a foam wedge behind my back for additional support.
The final result is an inexpensive trike-wheel which performs well on wet/soggy or rough terrain when it is not too rocky or rooted, particularly when combined with knobby tires. The profile of the trike wheel is small enough to use indoors or on crowded sidewalks without creating a tripping hazard. As a practical matter, I only use it outdoors as needed. My DIY Trike-Wheel has transformed my appreciation for gravel and dirt trails. I used to find them highly annoying as my casters bumped into the small rocks and obstructions causing jolts and vibrations. Now I enjoy these same trails as my DIY Trike-Wheel glides over the terrain.