What is a Mid-Wheel Drive Wheelchair?

Jazzy Mid Wheel Drive Power Wheelchair

Mid-wheel drive wheelchairs are power wheelchairs that have their drive wheels mid way between the front and the rear of the wheelchair frame. Power wheelchairs are also available in front wheel (fairly rare) and rear wheel (very common) drive configurations but the mid-wheel power chairs seem to be the most popular these days in many areas.

Turning Radius

The turning radius of the mid-wheel drive wheelchair is smaller than that of other the front wheel or rear wheel drive wheelchairs. The mid wheel will basically turn a full circle in its own length where the front wheel drive will take about one and a half times its length and the rear wheel drive will take almost twice its length.

All power wheelchairs have two powered wheels that are driven either forward or backward depending on the direction the user wants to go. When turning, the drive wheels actually turn in opposite directions, somewhat like the tracks on an army tank, to shorten the amount of room required for the turn. When turning right, the right wheel will turn backwards and the left will turn forwards to spin the wheelchair to the right and vice versa for left turns.

When a rear wheel drive chair makes a turn everything in front of the driven wheels swing in the turn direction. With a front wheel drive wheelchair everything behind the driven wheels swings in the opposite direction of the turn. Front wheel drives can be especially difficult for some users because they can't see the part of the wheelchair that is swinging around and can easily knock over furniture or people when making sharp turns.

A mid-wheel drive wheelchair swings for the center so that half the length is swinging behind the user and half the length is swinging in front. Because only half the length in either direction is swinging around the issue of hitting things is greatly reduced. The turning characteristic is the greatest benefit of the mid-wheel power wheelchair because it is so much easier to manoeuver indoors and in small areas.

Drawbacks of Mid-Wheel Drive

Although the short turning radius usually outweigh the drawbacks of mid-wheel power chairs there are a couple of issues that cause some people difficulties.

1. Mid-wheel configurations have a pair of swiveling casters at both the front and rear of the frame. These casters have to have some sort of suspension to allow the to rise and lower when passing over low obstacles without lifting the drive wheels off the ground. Because of this suspension, the mid wheel configuration will sometimes feel like it is tipping forward or backward when climbing or descending inclines.


2. The second issue with mid wheel configurations is they can be hard to control at high speeds. They tend to "fishtail" a bit when driven too fast. Front wheel configurations are worse but rear wheel configurations are better. If the user wants to race a round town a high speeds they will want to stick with a conventional rear wheel drive wheelchair.


3. Some people who are experienced with the rear wheel configuration power chair can't get used to the turning characteristics and aren't comfortable changing from what they are used to using.

As with any other wheelchair, power or manual, it's really important for the buyer to try a version of the chair they are considering before they make a purchase.