A Bicycle for Brother Steven–Part I (of ?)

In the last post I described in devices for performing exercise using electrical stimulation. I also described reasons why such devices might not be the right choice if you were capable of performing exercise with you muscles without external aid. I considered the idea of a bicycle with little or no resistance. Most exercise bikes have a fair amount of resistance built into the basic design. While I was shopping at Costco I ran across a bicycle where the pedals drove a large metal flywheel. What was interesting about the design was that if the resistance on the wheel were removed, the device would be very easy to pedal. Looking at that stationary bicycle got me to wondering whether it was possible to put together a bicycle that I could pedal.

There are a large number of problems in this design. First, my legs are extremely weak and can generate relatively small forces. Second, I have very little control over the placement of my feet and without significant effort they will simply slip off the pedals. Third, my feet tend to flop to the side and some kind of mechanical device must be used to keep them center over the pedals.

As we tested various stationary bicycles I developed what I call the pinky test. The rule is simple if you cannot push the pedals with your pinky finger then there is too much resistance for me to use the bicycle. Most bicycles that we tested failed the pinky test. The design that seem to work the best was the one that I saw at Costco, the pedals driving a flywheel with any resistance placed on the outside of the wheel. These devices are fairly expensive, around three hundred dollars which is a lot to spend on something that you have no idea whether or not is going to work. One day someone posted an ad on craigslist for a bicycle of this design with a much smaller flywheel than most of the devices we have been looking at. They wanted twenty dollars for it and I bought it immediately.

Now that I had a bicycle, see the picture above, I had to solve all of the other problems listed above and any new problems that I would find. There were plenty of problems to find and I will describe them later.

The first problem was how to attach my feet to the pedals. We decided that the easiest way to do this was to buy a shoe and a bolt the shoe to the pedals. If you would keep my feet solidly in place and as long as it was easy to get in and fasten, we chose one that fastened with Velcro, it would keep the feet in place and not make getting on and off too difficult.

The next problem was how to keep my legs from flopping to the side. Copying a design I saw on an FES machine we attached a bar to the pedal that came up to a curved piece of plastic having a band that wrapped around my leg. Designing such a system to be rigid but not too rigid and strong enough to hold the leg in place was a major challenge and after several designs I am still not sure that what I have is working properly.