Hard (for me) to believe but I did that back in the 70s. Not the physical knocking down part though.
I went up the old Tetley Walker chimney which was 300 feet. Straight ladder, no hoops, no harness, no hard hat.
I climbed over the top section as you see Fred doing.........that part was fine, it was climbing back over to get back on the ladder I found a bit scary.
I have a few copies of 'Old Glory' magazine, & one has a feature on his house, & was taken into it, prior to the Auction
(although, the magazine staff had been there many times during his habitation of it)
He often mentioned riding along the canal with his Dad as a youngster but never said anything else about bikes in his programmes that I can recall. I'm sure he would have had a rod braked roadster somewhere. It would be his type of bike.