I wanna buy a mountain bike. How difficult can that be? It's just two wheels, a seat, a frame, some gears and brakes. Just choose between red and silver and you're ready to roll, right?

Not quite. Although buying a mountain bike isn't in the same financial league as buying a car, it requires almost as much thought:

Where do you want to ride it? Mostly paved roads? Dirt roads? A combination?

How often do you ride?

Who will you ride with, and what kind of riders are they? How are your skills?

How much can you spend?

Thinking about your riding companions probably is the best first step, says Chris Rossow, a sales associate at Criterium Bike Shop, 6150 Corporate Drive.If your bike isn't match- ed to the other riders', somebody is going to get left behind," Rossow says. That's especially important for families that ride together.

"They don't have to be the same make and model bikes, of course, but they should match in quality."

Starting with that in mind, here are more suggestions from Rossow, Brian Hsieh, sales associate and mechanic at Bicycle Village, and others to consider when buying an entry-level bike:

1. Decide how much you want to spend. Mountain bikes that can handle trails and roads usually cost from $300 to $500. The low end of that range will get you chromoly, a quality steel alloy (a blend of metals) frame. The high end will get you aluminum, which is lighter and stronger. When prices hit four figures, your options include titanium and carbon fiber, even lighter and stronger than aluminum