I think the only way to be sure is to do the commute.
I would say that clothing is probably going to make more of a difference than fixed or gears for a 20 mile each way commute, as long as it's not 1,500 feet all at once.
@Dammit 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 the only way to be sure is to do the commute.
I would say that clothing is probably going to make more of a difference than fixed or gears for a 20 mile each way commute, as long as it's not 1,500 feet all at once.