its a rough rule of thumb, but as you get to extremes it has less use (much like bmi)
It's not a rule of thumb. It's a load of bollocks.
@Prime_heretic 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.
It's not a rule of thumb. It's a load of bollocks.