I have a giant boulder mountain bike, and I do have a fair knowledge of bikes but I know nothing about headsets, my mate had a bike come in to his work shop that had been in a car crash only the back end of the bike got crushed, so he gave me the forks. They are rock shocks duke xc u*-turns. I put have put them on my bike but they don't fit in to the headset, I know that the forks need a 1 1/8" headset. So can I just buy a headset and stick it on my bike or do I have to get the right angles and stuff like that?

Bring the frame into the LBS they will Measure the head tube bore , the headset insert needs tio fit in that hole.

If the fork will work with the frame, you do not need to buy anything. All you need to do is transfer the fork crown race from the old fork to the new one. It is possible to do this yourself, otherwise an LBS would probably do it pretty cheap. It is a small and quick job. Things you need to check:

- Your frame MUST have a 1 1/8" fork now or the new fork will not work. See: https://sheldonbrown.com/headsets.html
- Make sure the headtube on the new fork is as long as the headtube on the old fork. If it is much shorter, it may not work unless you have a bunch of spacers stacked up on the current setup.
- One last consideration: disc or rim brakes? Make sure it uses the same system, otherwise be prepared to buy a disc brake and wheel.