Some n=1 testing in an article a while ago suggested you'd lose ~15mins every 100km. Pretty significant over the course of TCR.
Edit: article here
Interesting the article says that it is less a factor on a hilly route. There are many advantages of panniers also: lower to the ground for better handling, easy to detach, easier to pick up the bike by the frame as they don't obscure it.
@Squaredisk 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.
Some n=1 testing in an article a while ago suggested you'd lose ~15mins every 100km. Pretty significant over the course of TCR.
Edit: article here