There's an aero benefit to having a rider on your wheel also I believe.
It's tiny though.
3.5% lower CdA on average
@Brommers 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.
There's an aero benefit to having a rider on your wheel also I believe.