Need newbie guideance on replacing fork

[DH]

I'm pretty new to bike maintenance. I've had a lowend bike (Specialized
Hardrock) for about 4 years now and serves all of my needs which are mainly
neighborhood getting around with the occasional trail.

Cue some animal who tried to steal it off of my bikerack. I had it secured
but they still managed to seal the front suspension fork. So now I need a
new fork and some advice on what I'll need to install it.

I've looked on ebay and see a bunch of rock shox low-end forks similar to my
old one going for around $30-$50 which is about what I can afford for this
bike. Having never messed with the headset/fork I am pretty clueless about
what I need. How do I know what size fork to get? It is easy to install?
What do I need to know about the headset? The only think left of the headset
from the theft is a ball bering ring.

Any help appreciated.

 

[spademan o---[) *]

You almost certainly need a fork with a 1.125" (1 1/8") diameter
steerer tube, and you will also need a new headset (also 1.125). I'd
buy the headset new as these tend to wear out especially at the price
range you're looking at. A basic FSA orbit or WTB greaseguard should
see you alright. Second hand forks will have has the steerer tube cut
doen to fit the bike they came off. To ensure they will fit your bike
you need to calculate the minimum steerer length you will need. To do
this, measure the length of the frames headtube (the tube the forks fit
through), the height of your handlebar stem, any spacers you had under
your stem, and the height of your new headset (usually around 40mm,
don't include the bits which press into your frame). Add these together
and you have the minimum length of steerer you will need to look for on
a second hand fork.
You will also need to check the forks have the required brake mounts,
some older forks only have mounts for 'V' brakes, some newer ones only
have mounts for discs.
Lastly, I'd strongly recommend getting a rigid fork, it will require
less maintenance, be better quality for your price range and be less
attractive to scumbags.
Steve.