It's just standard roadie advice
To cover your knees? Why?
Just a guess but long term typical cycling injury will be bad knees. Better off riding with them covered to stave off all manner of ailments for a while longer, arthritis speeds up with the cold I think.
@Clockwise started
London Fixed Gear and Single-Speed is a community of predominantly fixed gear and single-speed cyclists in and around London, UK.
This site is supported almost exclusively by donations. Please consider donating a small amount regularly.
To cover your knees? Why?