I will never tell my wife this… I convinced her that I needed a commuter specific bike. I bought a Fuji Royal, a relaxed road bike with mountain style bars. My thought was more upright = comfort… Unfortunately, it also means “wind drag.” It came with 26c slicks which I have yet to replace, but will soon. Something closer to 32c (i.a.w. 1.25”) I ended up putting on an aero bar to help cheat the wind.

Bottom line, I was equally as fast commuting on my mountain bike with 1.25” slicks! Everything I use to commute with, with the exception of my rear rack (they make these quick released also), is quickly removed if and when I want to use the mountain bike for its intended purpose.

My recommendation is to buy a bike that you want to ride. Then make sure what you add to commute with is easily removed.

As far as gear:
My commute doesn’t include street lights so I need plenty of light. I really like my rechargeable halogens (two 10W headlights). If the lights are so people can see you I would get a couple LED lights.

I would stay away from sidewall dynos, they are to limiting as far as tire selection and creates drag.

Based on my 26mile round trip commute and $0.30/mile that I am saving by not driving my car, to date it will take me another 107 commutes to pay for a bike that I really didn’t need. sshhhhh!