I’m glad I invested in this kit. It gets me up slopes, it helps me walk the dog and keep up with grown-ups. It’s reliable and the lithium battery lasts long enough for me (the Bluetooth wristband controller, without which the whole thing is dead-weight, does not). The only real problem is, the thing has a life of its own.

My home is surrounded by a path of fake york-stone flags, laid when I were a lad and a lot more mobile. Most times I negotiate these safely but, every so often, I time it wrong and bounce off an edge. It’s the same with kerbs and unexpected stones. The front castors stop abruptly and so do I. But no matter the obstacle, unless you stop it by tapping the wristband, the SmartDrive will power on at the selected speed. It will soon overcome the clamp and push itself through the vertical to cut out in a facing forward position.

And then, basically, you’re shafted. The only way to reset the device, back to the facing aft condition, is to get out of the chair. If there’s a seat nearby it’s a 30-second job but if not, all you can do is shuffle your sorry ass to the ground. It takes but a moment to reset but then, of course, you have to get back in the chair, a manoeuvre that I find increasingly difficult in me old age.

If you spend your life cruising through airport terminals and exhibition halls, you have nothing to worry about. But if you live in the real world, this can be a real issue. You need to keep the clamp tight but there is a limit to the torque you can apply with the Allen key supplied.

This condition can be avoided by coupling a FreeWheel to the front of the chair. It lifts the front casters off the ground and makes life, with and without a SmartDrive, a lot smoother. Leaning backwards helps as well.

Finally, it’s a good idea to turn the device off when you don’t need it. Several times I have patted the dog and immediately run him over.