ive been riding a 10 speed for a while and ive ridden some of my friends fixed gears and enjoy it so im planning on building one. but i want to make one that can go off a curb or maybe a set of 2 or 3 without damaging the wheels or frame. ive even heard of people being able to bunnyhop on fixed gears or go up curbs, all of which is unthinkable on a regular road bike. are there any specific frames, wheels, or forks anybody might be able to suggest for me to accomplish my goal of building a fixed gear that can handle just about any urban environment? any help would be greatly appreciated. thanks in advance!
If it's unthinkable to bunny hop or go on curbs with a road bike, I'm not sure how you expect to do it on a fixy. Like pythons said, it's easier on a road bike because you can coast. Otherwise it's only a matter of individual components which can be mostly the same on both types of bike.
Bunny hopping and curb jumping on a road bike is all about technique and is hardly unthinkable. It requires a certain amount of grace and elegance that is not as necessary on a mountian bike. Doing so on a fixed gear just requires more grace. Just learn how to ride.
you're going to get several people recommending a basic steel frame. i will too, though i've never ridden aluminum. also, well-built wheels are going to be what you want in order to withstand impacts - IRO (www.irocycle.com, search the forums for more info about them than you can handle) gets their wheels handbuilt by velocity. there are a lot of cheaper wheels out there with similar hubs and rims, but a lot of those don't come with desirable trueness or tensioning, and that's a trip to the bike shops and twenty bucks or so to straighten that out.
there are lots of affordable bikes that can take this curbhopping, stair-taking beating. my IRO Mark V does it quite well; search for the thread about budget bikes (i think it's called "a discussion of budget single speed and fixed gear bikes" or something like that) for lots of information about which ones and some of the pros and cons of each.
i find bunny hopping tough, but curb hopping no problem - lift the front end and then lift the rear end. not exactly one fluid motion, but smooth enough and it gets me off the street and on to the sidewalk when i'm dismounting.