Wheelchair Spokes Versus Mags
There are several types of wheelchair spokes to choose from: spokes, billets, mags, and high performance wheels. The spokes vary from 12 on the high performance wheel to as many as 30 on the spinergy wheel. The rear wheels can have the pull hub which allows the user to quickly pull the wheels for easier portability during travel. The billet style wheels are usually machined aluminum.
Compression spokes were used originally for horse drawn carriages or wagons and made of wood. In this type of wheel, a load on the hub causes the wheel rim to flatten slightly against the ground as the lower wooden spoke shortens and compresses. The other wooden spokes show no significant change. The wooden spokes were radially mounted to the outside of the rim to prevent wobbling.
Bicycles use the tension spoke thus the invention of the lighter wheels with adjustable tension spokes known as wire wheels. Since bicycle and wheelchair spokes are only in tension, flexible and strong materials such as synthetic fibers are often used. To reduce aerodynamic drag metal spokes can be oval or bladed, and when doubled or tripled in the number of spokes while maintaining strength.
Some types of wheels haves spokes that can be individually replaced should they break or bend.
The reaction to the load is that the tire flattens slightly with the bottom most spokes flexing slightly, and the tire remaining circular. The tension of all spokes is not increased instead those near the ground decrease.
This issue is debated by many in the field.
Mag, molded or composite wheels in wheelchairs are said to be more durable and require less maintenance.
Molded wheels are heavier than spoke wheels. They have a small number of wide molded spokes that are a part of the wheel and cannot be replaced or repaired when broken.
They are not as flexible as spoke wheels so users may experience a rougher ride. The lack of flexibility makes them more likely to crack on hard impact.
Hubs contain axles, are in the center of the wheel and are important to connect the rim to the frame of the wheelchair.
There are new bolt on hubs made from lightweight titanium for fast acceleration, smooth riding and maintaining speed. Depending upon the use there are low, medium and high flange hubs in various sizes. Most hubs have sealed bearings and are made of machined aluminum. There are steel bearings and ceramic bearings. Ceramic bearings are said to last longer than steel bearings.
Phil Wood has wheelchair hubs for a threaded axle, recreational hubs, and racing front hubs. Threaded axle hubs are available in high and low flange hubs and are sold as sets. Disc brake hubs are available and are sold as individual hubs.
Surelock has created the Lock n Roll wheelchair locking hub system. It provides a secure and consistent wheelchair locking system by employing a positive locking mechanism that engages at the wheel's hub, not the tire.
The system consists of the activator body with lever which is mounted to the wheelchair frame, a locking pin mounted at the end of the wheelchair axle and wheel hub disc with 27 holes that accept the pin.
Simply flip the lever, the locking pins spring out to locate one of the 27 holes on each wheel's hub disc locking the chair. Move the lever back and the chair is free to roll.
The wheelchair spokes or mags connect the outer part of the tire to the hub or center of the tire. Spokes are usually found on manual wheelchairs that are used every day and some multi-purpose sports wheelchairs. Mags can consist of as few as three and usually have eight “spokes” connected to the rim and are usually heavier.
Wheelchair spokes, although less expensive and lighter need to be aligned which means they require more maintenance. If the spokes are not equally tight the wheel will wobble when it is spun.
The mag wheel also known as a composite wheel is stronger and requires less maintenance. The mag wheel is found on power chairs.
Hubs contain the axle and are important to connect the wheel to the frame of the wheelchair. There are different types of hubs, depending upon if you need to take your wheels off your chair for easier transportability to special hubs for sports chairs.
What type of tire should you use? Read more to
the different types of tires.