Question 1 reminded me of my late father. After an accident, just before WW2, he had his knee joint removed so his left leg was completely stiff. However, this did not stop him continuing to work and he could skin up a ladder on to the roof of a house, he was in the building trade, as well as anyone. He also rode a push bike, adapting it to fixed wheel and just the chainwheel turning, the other crank welded so that it remained at the bottom and on which he could rest his "stiff" leg whilst he pedalled with his good one. One of us three kids could be accommodated on a little saddle fixed to the cross bar. Of course he was not a recreational cyclist, not sure he knew what recreation was, but cycled back and fore to work several miles every day. He eventually elevated to owning a cyclemaster, engine in the rear wheel contraption, which made his working day easier. When modernising our home, in the early 60s, he bought a new door to put on the room he was converting into a bathroom, what luxury, and was carrying this home , under his arm, whilst riding his bike. As it was a busy city road he stopped at the kerbside when he wanted to turn right across the traffic and at this point a police car drew up. Accused him of riding a bike in a reckless manner. He might have got away with it, merely pointing out that if he hadn't been in control then he couldn't have stopped as he did, but when the policeman asked "how big is that door, 7 foot?" his response of " If it is it won't fit my bloody doorway" sealed his fate. Fined £5. As he said. Expensive bloody door!