Originally Posted by rxc
Go to a bike shop (I use The Missing Link by the way) and try out some bikes. Look for something comfortable, without mountain bike tires, and at least a few gears in the rear.
You're gonna need "mountain bike tires" when it rains. It's no fun hydroplaning down a hill towards a red light, trust me, I'll stay away from skinny tires, what little efficiency you gain from skinny tires is not worth dying over. Also, wider tires won't get caught in cracks as easily and of course you can brake harder, so it's just safer all around. As far as gears go, you don't need more than 18 (3x6) for riding 3 miles to work, anymore is just extra weight and complexity (that said, I have 27 speeds and XTR drivetrain and brakes, but I ride for run in the Arizona desert).
Originally Posted by pennylane
Do commuter bikes only have one gear or something? I seriously have no idea how these things work. Bear with me.
Some bikes only have one gear and they're called 'single-speed' bikes, there's a cult following amoungst bike afficionados for singlespeeds kind of like there is a cult following for tube amps around here. It's an oddity, and the idea is that if you get rid of all the gears and all the levers and cables and housings and springs then the bike can be made much lighter and simpler and there'll be fewer things that can go wrong. But really, in real life, you're gonna need gears to go uphill or through a thick lawn or sand or something, so singlespeeds aren't really practical.
So, instead of a hybrid or a cruiser or a roadbike, I'd recommend getting a mountain bike. They'll last you longer and can handle riding down a curb every now and then. The skinny-tire commuter bikes (like the Trek 7200) tend to have weaker rims and you won't be happy when you bend your rim the first time you ride into a tree (which is just a fact of life
Anyway, like I said, look into the Trek 820. The Trek 3500 has a lighter frame but all the components are the same and it's not worth the extra money in my opinion if you don't intend to ride for thrills. Also, just like headphones, you want to test ride the bike before you buy it, what's a good fit for one person will not necessarily be good for another. If you tried Trek and don't like the fit then look into other brands like Cannondale or Raleigh, different brands will have different geometries. Treks tend to have one of the shortest top-tubes (so you sit more upright) and Raleighs tend to have the most aggressive geometry where you lean more forward, other brands fall in between.