• I realized that weight and aerodynamic position do matter
• Sheldon Brown: "The main advantage of drop handlebars is that they offer several different hand positions. ... People who think they don't like drop handlebars are often actually objecting to the position of the bars on the drop-bar bikes they have tried. If these people tried a bike where the drop bars were placed higher, and closer to the saddle, they might find they really liked them."
• TODO: find the link (there's an article where a guy says he rides singletrack on a roadbike, keeps up with the mountain bikers offroad, and blows them away when the hit asphalt... his arguments are that 1) mountain bikes don't need to be as heavily-built unless you're one of the few who freeride or downhill, and 2) that skillful bike handling can go a very long way in making up for a weaker frame)

Cyclocross

• mud? snow? Hell yeah, road bikes can do that and more.
• Wheelies? Sure, that too.
• differences from a road bike:
  • slightly thicker tire
  • frame has more clearance for any size tire (something that Sheldon Brown criticizes standard road bike manufacturers for... there's no engineering reason not to build extra clearance into all but the lightest road bikes)
  • slightly thicker frame
• differences from mountain-bike trails
  • more wide-open, no rocks, no crazy downhill sections

Criteriums

• higher bottom bracket so they can pedal while cornering hard

Handlebars

• great overview of major types, along with tips about changing between them
• good overview of lots of different ones, along with possible hand positions
• drop bars for MTBs, pictures
• lengthy consideration of moustache bars

TODO

• go watch a few Cyclocross races. This makes it clear that there IS a difference between MTB and cross, and that cyclocross is one of the battlegrounds of that mix.
  • Chicago Cyclocross Cup
  • cyclocross events (since cyclocross is a "winter" sport, they tend to start in September)