I am looking for a Winter project. I want to re-build my 12 year old steel mountain bike. I want to use it on road for the Winter. It needs almost all new components.
I removed the components. It has a rigid fork. This is the problem. I measured the the distance from dropout to dropout. It is about 105mm. I would like it to be 100 so that wheel would fit in without having to move it from side to side to center it. Does anyone have a clue how I can accomplish this?

Thanks in advance

Does anyone have a clue how I can accomplish this?

Thanks in advance

It helps to have a fork alignment tool, but you could figure out how to do it without one. Figure out which leg is off center, or if both of them are, and by how much. Bend it back into place. Check the wheel alignment with a wheel you know to be in dish, and grind a little off one dropout or the other if needed. That's it.

It's not hard, but I've never done it without a fork alignment jig, and it helps to have a purpose-built cheater bar, because even super-thin modern steel fork legs can be pretty stiff. In all truth, if it's only off by 5 mm and this is a commuter-beater, I'd just leave it alone. Or you could just squeeze them as they are (with your hands, c-clamp, vice-grips, etc.) and hope for the best...

Thanks for the info. This fork is so strong that there is no way that I could sqeeze it together by hand. Please elaborate what tool I could use. The 5mm probably does not matteer, but now that I have measured it, I feel I must address the problem.

Thanks

Thanks for the info. This fork is so strong that there is no way that I could sqeeze it together by hand. Please elaborate what tool I could use. The 5mm probably does not matteer, but now that I have measured it, I feel I must address the problem.

Thanks
Bolt, nut and two washers a start tightening. Check every few mm because it is going to go all at once. - TF

Please elaborate what tool I could use.

You could use a F O R K A L I G N M E N T J I G. Again, as I stated earlier, I have no idea "what tool [you] could use."

The 5mm probably does not matteer, but now that I have measured it, I feel I must address the problem.

Dude, is it not a winter beater? I mean, seriously - you "must address the problem"? R E L A X.

Basically this is the same idea as TT proposes. I would go to the hardware store with the fork and buy a combination of threaded rod, nuts and washers that will do the trick. The advantage here is the you and do the process slowly and in a "controlled fashion. I agree that you want to be careful not to go too far.

Though it is a beater bike, I plan to put on some decent components. I often do substantial rides on it.
Another alternative is to buy a new fork. They are pretty cheap for a threaded rigid steel one. If I go the new fork route, can I use the Park cutter guide for this? It was meant for threadless steerers. I don't want to buy another guide for just one fork.

Thanks

I cut a threaded fork last night.

A Park guide is certainly your best choice but I never use one.

I use my Dremel with a cut off wheel.

I put the fork on the bike and threaded the top cup on. I measured for the top nut and small spacer. I held the mototool in one place and rotated the fork. it was a perfect cut.
Once the steerer is cut, you can unscrew the top cup to clean the threads.

I squeezed the blades together and got it within a couple of mm from perfection. I put a front wheel in the fork and measured both sides. It seems to be quite good. I guess I will just put back the fork, and then order new components.
Thanks to all for you kind replies.