I think its so that when the bars spin around (for example when you are carrying it) the top tube is not damaged by the bars if they hit it.
@tedward 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.
I think its so that when the bars spin around (for example when you are carrying it) the top tube is not damaged by the bars if they hit it.