needing new front suspension I have an old Schwinn sidewinder 2.6 mountain bike. I'm starting to get into better trails and I want to upgrade my front suspension. It has the standard 1-1/8 steering, but its a threaded shaft. Does this mean I can't upgrade to the new "smooth" style forks that are readily available?  I guess in short can I put any suspension in my bike if i change the front forks and handlebars?  I don't know much about bikes suspension and what can be messed with and what can't.
Thank you 
Kyle
Given that the Schwinn sidewinder is a Walmart bike, you're best off getting a new bike. We call these BSO's or bike shaped objects. 

By the time you get a basic suspension fork, you'll be spending more than the bike after installation, whereas you could easily buy a good used entry level front suspension mountain bike (say, a Specialized Hard Rock or Trek 3700 or whatever) for slightly more, which will be way more durable and better quality components.