You, as a purchaser, have a right to have the machine work as it ought, for several years. We also want this to happen, so we did endurance tests and fracture tests and general harsh tests.

Wear Test

We ran the wheels in the laboratory, with an air cylinder stroking the handle back and forward. We ran it for 2,000 km. We loaded it as if it were a 100 kg (221 pounds) person going up a ramp of 7 degrees. Legal ramps are gentler than 4.5 degrees. Our laboratory wheel could have climbed Mount Everest forty times with the same effort. The wear elements in the mechanism showed no measurable wear from the test.

Before each wheel goes out to the customer, it runs on this machine for one hour at 6 km/h. The machine uses  a pneumatic ram and is controlled and monitored by a computer. It measures the force of each stroke. The tyre runs on a roller that turns a DC motor/generator. By varying the resistance across the generator leads, we control the resistance to motion. The machine is set so that every stroke requires 40 kg to turn the wheel. To put this in perspective, when going on the straight and level, you will use about 1 kg of force.

Our test wheel didn’t get off that lightly. It ran for 2,000 km at this load. That took 340 solid hours – 14 days, running 24/7.  We then stripped it and examined it. It showed no scars from its ordeal.

Strength Test

We got a strong athlete and paid him to try to break the wheels. He was capable of a 110 kg (250 pounds) bench press. The average user of this chair might be able to bench press 20 kg (44 pounds). He ran the chair for 5 km and didn’t break it. Of course, the elements of the chair had already been carefully designed using sophisticated software but, there’s a difference between theory and practice. Actually, in theory, there is no difference between theory and practice. In practice, there is.

Harsh Test

We employed several workmen (workmen are very strong) to run the wheelchair and paid them per circuit of a rough outdoor track. Consequently they went as fast as they could. The limitation was not capsizing over the bumps. They ran in relays and covered 700 km over roots and bumps and broken pavement. No problems.

Inclement Weather

We put the chair in a refrigerated room at zero degress Fahrenheit (-18 C) and it didn’t mind at all. It could have a problem when you bring it in from the cold into a warm room because the warm air will mist on the surfaces of the clutches. You will probably want to be in standard mode indoors anyway – and that will be unaffected. RUN mode will come back in a while.

We ran the chair in the rain and found that, in a prolonged heavy rain, it could start slipping in RUN mode. It still worked fine in Standard mode so you can get home, with a new feeling about how nice it is to be in RUN mode. In a light rain for a while, it was happy. When it got soaked and started slipping, we allowed it to stand overnight in a warm room and it was OK, as we would have expected.

Failures in service.

Despite all our design care and testing, we cannot guarantee that nothing will ever go wrong. Of course, we warrant all parts for a year against breakage but we don’t want our customers to be unhappy. So, if anything goes wrong, in the first instance, contact us ( We will do something nice.