You Cannot Ride This 'Backwards Brains Bicycle'

Interesting video!

Should be able to do it if you crossed your arms.

Makes sense to me. You train your reflexes to respond instantly while steering a bike, because if you had to take the time to think about it, you'd crash. Retraining a different method is a great experiment, as long as someone else is doing it.

The closest real-life analogy I can think of in my own experience is roller skating. I was pretty good at it when I was young. Then I didn't skate for twenty years, just walked. When I took it up again to skate with my kids, it took a good twenty minutes to realign my reflexes (which was quite comical), then suddenly I was as good as I ever was.

But once he learns how, he'll never forget.

I wonder if he would have had as difficult a time if the bike was the correct size for his body? The small frame and low seat force him into a very awkward "stance". for example, his knees hit his elbows.

Propeller-driven fighter planes had similar issues. The centrifugal force of the spinning prop and heavy rotary engine meant the controls responded 90 degrees offset. Lots of pilots crashed for no other reason than being unable to re-train their reflexes.

Thanks to my multiple-layout typing, I actually know the trick to being able to switch your motor controls back and forth. What you need is strong contextual hints. The fewer visual, tactile, etc., differences, the harder it is for you. If the reverse-steering bike was dramatically different than every normal bike, it would be much easier to switch between them. But since it's practically identical to regular bikes, it's vastly harder for your mind to distinguish when to apply each different motor skill pathway.

I'd try modifying the reverse-geared bike with drop/racing handlebars, painted a unique color, hornless seat, streamers, etc. In fact starting with a recumbent bike would probably work pretty well. Alternatively, you could (probably) manage it by only ever riding your reverse-geared bike on one or two certain road/trail/paths, and NEVER riding a regular bicycle down those same locations. If they are sufficiently obviously different than each other, you won't get confused.

I remember experiencing the opposite situation, where something I understood and had muscle memory for was mixed up by trying to think about it too hard. For example, when I learned more about the idea behind counter steering on a bicycle, I suddenly had a trouble steering if I thought about it too hard, even though previously I intuitively was already doing it.