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 3,000 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 sixty 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 3,000 km at this load. That took 500 solid hours – 21 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 couldn’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
Several testers went as fast as they could. They covered 800 km over roots and bumps and broken pavement. On average they had to handle ten curb cuts per kilometre. 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.
We ran the chair in the rain and found that, it cared less than we did. It will run under water.
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 (customerservice@octalwheels.com). We will do something nice.