I have a univega and a fixie. i love the idea of fixed gear bikes but live in a very hilly area which requires more than just one gear. Is there a way to combined those two ideas into one awesome cycling machine? comments are appreciated. thanks.
How about a Schlumf drive?
The Schlumpf drive is an ultra thin planetary gearing system located at the right end of the bottom bracket, between bottom bracket and right crankarm. Installation of a Schlumpf drive hardly changes [either the] position of the chain nor position of the crankarms.
They're probably expensive, but I don't think they have a freewheel. Plenty of people use them with hub gears for extra range. You tap the centre with your heel to shift - not as easy or quick as a lever on the bars, but they look pretty minimalist as they don't have any cables, which seems to jibe with the fixie way (if I've understood it right?)
I had the same dilemma and the best idea I came up with is a fixed internal gear hub. Sturmey Archer make a 3-speed fixed hub that looked the goods. The way this works is that there's still no freewheel (the same as a fixie) but there's a gear cable coming out of the hub that allows you to select between 3 gears.
On the bike it looks a little like this:
A bit pricey, but on the right bike this could be awesome.
Apart from the Sturmey hub, the only other option I know of for a multi-speed fixed gear is something like http://surlybikes.com/parts/dingle_cog
You have two sprockets on the rear, and two chainrings on the front, carefully chosen so they work with the same chain length. To change gear, you stop, get off, move the chain onto the other set of sprockets, then ride off again.
But you probably don't want to do that at the top and bottom of every hill, any more than you want to take off a wheel with a flip-flop hub and turn it around.