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I got run over a car a few weeks ago and now i have to change the fork. It's an old racer, as you can see in the picture, with a 1 inch fork. I am trying to loosen it from the frame, but I can't loosen the bolt marked with 2 because of the rust and now it's completely gone. Any advice?
I couldn't post any picture, but the stem and fork is similar to this one:
And the bolt I am talking about is the one that is in the stem and goes to the fork.
You'll need an allen key - probably a 6mm one to take off the stem, which is the silver part that holds your handle bars. If you loosen the bolt and it keeps coming up, hit it with a plastic mallet to knock it back down which should loosen that.
Once the stem is off you will need a headset wrench, probably 32mm. Having 2 helps because it's basically a double nut that holds the stem on. The lower one holds the stem in place and the upper one locks it into position. If you've stripped the nut, I would take it to a shop and they'll have to do some additional work on it and most likely replace your headset.
If you were in a crash, I'd have a bike shop inspect your bike front to back. A crash can do a lot of damage that the untrained eye will not be able to spot and you could be riding a cracked frame or otherwise dangerous bike.
If it's rusted, you will also want to try some "Creep" (lots of brands out there, Liquid Wrench is popular on East Coast) penetrating oil. Straight oils won't get in where you need them.
Note that the penetrating oils have solvent in them so you will want to clean, degrease, and re-oil after you get everything apart.
If you still have issues, you might consider cutting off the fork from the bottom with a hacksaw (since you are replacing it anyway) which will give you more access to the stuck parts.
What you need is the proper size of headset wrench. Take your bike into a bike shop and ask them for the proper sized headset wrench for your bike.
Occasionally it helps to have two headset wrenches or a nice big adjustable wrench so that you can work the bolts against each other if they are binding.
If you're stripped the bolts, I would recommend filing off the rounded bits if they aren't stripped too badly, or using some channel locks if they are stripped too badly.
If you're ok with destroying your stem, sawing through it will definitely work. You won't even have to get all the way through it, just a bit over half. Once you've sawn through the bolt that runs through the center it'll all come apart just the same as if you'd unscrewed it until it came out.
That said, I've never sawn through a stem before. I don't imagine that the metal would be too hard for your garden-variety hack saw, but some bike parts are (I'm thinking specifically of a bottom bracket spindle).
