Originally Posted by
jsdavis
One thing I am concerned about buying used is how do I differentiate a cyclocross bike or touring bike from a road bike? Is there anything that makes a them immediately obvious?
The most obvious visual difference is that touring and cyclocross bikes generally have cantilever brakes instead of calipers, so the necessary posts will be found on the frame and forks. Typically, they'll also be built to take wider tires than racing-style road bikes, so you'll notice more clearance between the stays and tire/rim. Touring bikes will often have longer chainstays for pannier (bag) heel clearance and will have wider/lower gearing than road bikes. I'm not sure if this is a generality, but my cyclocross bike has slightly lower gearing than typically found on road bikes. Cyclocross bikes may also have more higher bottom brackets than road bikes, giving them a little more ground clearance.
MattFoley mentioned the Bianchi Volpe, which I think would be a fantastic fit for you. It's not really a pure cyclocross racer or a pure touring bike, but it's kinda like what you'd get if you cross-bred them. It's nimble, comfortable, and can comfortably carry a load if you mount racks on it. It also has a triple crankset, giving you low gears to tackle some of those San Francisco hills.