Swapping the fixed / free

How quickly can this be done? Is it a pain? Or is it so quick and simple one really could decide on a per ride basis which one to use? Could one even opt for one or t'other for a 10 min pop to the shops?

depends how used to doing it you are, but yeah you could do it in a few minutes. you'll get used to one or the other though and i'm sure that you'll find that you prefer one more.

If you are talking about having a flip flop hub it can be changed over in 2 or 3 minutes. It's just a case of taking the rear wheel off and flipping in round (assuming you aren't fussed about having the tyre tread facing the wrong way).

I assume you're talking about a flip flop hub. If so, it should only take 5 mins, although like Teddy says you'll probably get tired of switching and stick to one or t'other.

EDIT: Beaten by Moog.

Tis easy, I've still got the free side on one of my bikes, to cope with the days when my ankle can't cope with the fixed side (which seems only to happen once every six months nowadays), or to cope with those hangover days where the ability to freewheel is a godsend. If I can change it quickly with a blinder of a hangover, anyone can do it!

Edit, in the time we've written these posts, you could have changed the wheel over!

A minute or two, 2 nuts off, remove wheel, flip, chain back on, 2 nuts back on. Decide chain tension isn't right, repeat. Maybe again. Clean hands. Not really a pain, just a little faff

What they said. Just need to make sure you run a similar sized cog both sides.

Assuming rear brake is present