I got this threaded fork and it is to long for my frame. Is the fork supposed to be the right length or am I supposed to just cut it to length? If not can I or will it mess up the threads?

the steerer is too long? you need to cut it to the right length. do a search for more info. use a pipe cutter or a hacksaw with a guide. make sure you leave enough extension...

DO NOT try to use a pipe cutter on a threaded fork....yer asking to screw up the threads. If you are gonna cut it with a hacksaw and dont have the proper threaded cutting guide....put an old steel threaded headset cup on the fork prior to cutting, it will help re-form the threads when you thread it off.

if it's not too long, you can also use a spacer under the compression nut rather than cutting the fork.

What cavernmech said.

But tell us: how much are you cutting off and how much threaded will be left when you're done? Because if you take off too much of the threaded, the headset might not fit on and they you'd need to thread it a bit more.

A simple alternative to cutting is to add some spacers.

Just thoughts.

i could have sworn that originally said 'threadless'. my bad.

I need to cut of a good inch to an inch and a half. So spacers don't seem like a good option. The headset cup? Is that the threaded piece that holds in the bearing?

forks can be threaded further. take it to a good lbs, have them extend the threads and then cut.

it dosent need anymore threads their long enough. It just needs to be cut.

You're going to have to take into account some factors from the headset that you'll be using. Are you sure you really want to do this yourself? how many great mechanics must there be in Boston?

"The headset cup? Is that the threaded piece that holds in the bearing?"

It might really be worth your while to have someone else do this for you...

I second that.
Take it to a shop.

Take it to a shop - should cost you around $10 - bring the frame too.

And the headset and stem. You need to know the stack height and all that to cut a fork.

... just the fork, frame, and headset. It's a threaded fork.

don't worry about screwing it up! i have a brand new fork i can let you have ok.

Thanks I ended up borrowing a hack saw from work and cut it myself and it came out fine.