A older friends dad was champion there a few times when is was part of the world championship in the 40's
When its foggy on top of the mountain, which it is alot, they count the corners as they cant see a thing at 100 mph plus.
Dont know if you know what this means but basically they lean into the first corner count the amount of seconds to hold it. straighten up count the amount of seconds to run straight and then lean into the next, count the amount of second to hold it again etc etc . Its a bit like pace-notes in a rally car but completely blind. These TT riders had
big balls I thought he was taking the piss but, he showed me his old notes before was all stolen when someone broke in and nicked his trophies and memorabilia a few years back