A non-comprehensive guide to some of the styles available.
Whichever you go for, they're all generally around £4000/$5000 . YMMV.
Depending upon your location, a dealer may bring one to your home for you to trial them. You're spending a lot of money so do not be afraid to ask.
Searching YouTube for these brand names should come up with a lot of examples.
Single Rear Wheel:
Smart Drive and Smoov are small motors with a single wheel that attach to the back of your manual chair. You control propulsion with a speed dial near your lap, and you steer the chair using your hands on the wheel push rims as normal. You can also push to contribute towards propulsion if you like. The extent to which they contribute towards overall speed is variable dependent upon your needs, but they can propel the chair entirely on their own, meaning all you have to do is steer.
Pro:
- They are both easy to attach/remove.
- comparatively light
- you have full control of steering
Con:
- sometimes have difficulty with steps/curbs as they're just clipped to an axle bar
- can feel less ergonomic/immediately responsive than devices attached to the wheels themselves.
Dual Wheel motors:
E-motion and WheelDrive style power assists are two motors, one on each wheel, which are connected to each other via Bluetooth. They each respond to how hard your hands push their respective wheel. This means you can set them to double your input, or treble your input, etc. They also have cruise control so they can propel the chair entirely on their own.
Pro:
- responsive, feel ergonomic. The force is kinda/ish coming from your hands rather than from a motor behind your bum
Con:
- rely upon Bluetooth, YMMV
- double the weight of single motor devices as there's one on each wheel, so if they fail for some reason, your chair is now very heavy
- you have to be careful how you push as every push is amplified and affects each wheel independently. Something to be aware of when you aren't pushing with each hand evenly, e.g, on slanted pavement/sidewalk, when you're turning/dodging, etc
Tricycle style devices:
These attach to the front of your chair with handle bars and a front wheel with a motor.
Pro:
- Great for longer distances
- some prefer handlebar steering
Con:
- less manoeuvrable. Your turning circle becomes very large.
Powerchair style:
There are also systems like the e-fix which turn your manual chair into a form of powerchair with a joystick to steer.
Pro:
- some prefer this undemanding mode of steering
Con:
- They add a lot of weight
- There's no middle ground, it's on or it's off, it's doing all the work or none of the work
Hope this helps
Please feel free to add first-hand experiences or any thoughts to this post, or let me know if I should edit anything
If they come for Karina "Drawfee" Farek they come for me