Hello all,

Noobie here with a question. I'm looking at purchashing my first real mountain bike. I'll be spending a lot of time on pavement, but I'm looking for greater versatility than a road rig can offer. I like shortcuts (not always paved), gravel and the housing developments that sprawl across suburbia. I'll also be hitting trails as often as possible, maybe once or twice a month since the serious dirt is further away.

I need some help on sizing. I'm almost 5'8" tall with short legs, short arms, and a long torso. This is a nightmare for bike geometry. My cycling inseam is 30.5" but since my trunk is overly long, I've got some problems.

Right now I'm looking at the Specialized Rockhopper with Deore shifters, disc brakes and a Rock Shox fork. I love the look and feel of the bike but am uncertain which size to get. The 15" frame gives me the right standover height but requires a custom stem to get the cockpit dimensions long enough for my weird-ass body. The 17" frame gives me about 2" of standover, but only requires some aft seat adjustment to get me where I need to be. It also feels like a better, more comfortable ride for me. Not by much, the 15" is good, but there's something about the 17" that just feels better.

I've been told by my lovely LBS that either will be fine for me. The 17 will be better and more comfy on the street, while not quite as snappy in the woods, while the 15 will be slower and more cumbersome on pavement, but easier and faster off-road.

In most of life's dealings, I'm a medium sort of guy. I'm not sure if Specialized's small bike is the right choice. I also don't want to get something just a hair too big. I've used all the equations on the various websites and books and, since they all differ just a bit, I never get a single measurement. According to Zinn's website, I need a 16.5. Another says I need a 15.3, and several say I should buy a 17.8.

Any suggestions from the veterans? I know measurements are important; I also know you should usually go with what intuitively feels the best for you, as all riders are different. I would welcome any input, though.

If it makes any difference, or breaks any ties, the 17" is a WAY cooler color.

-Z