HI:

Great write up

Regarding the brakes; I recommend that you consider changing to dual pivot side pulls; they are as effective as the linear pull brakes used on mountain bikes and hybrids. You'll need to measure the reach (http://sheldonbrown.com/calipers.html#reach) to determine what you need. I have Tektro R559 (http://sheldonbrown.com/harris/brake...ers.html#55-73) brakes on my commuter, and they took the bike from being scary to being very confidence inspiring. Amazon has many dual pivot brakes too.

Regarding tires - 23mm are awful on bumpy, or even slightly rough surfaces. From your description, I would strongly recommend that you stay with approximately the same size tires as you currently have. Maybe you can borrow a set (tires or even wheels) from another rider in your group to try out narrower tires. I believe that you will find that they may feel "tighter" but that you are not any faster, and on the rougher parts, you are actually slower.

Crank set: you may want to consider something like this: http://www.amazon.com/Shimano-Cranks...7768959&sr=1-3 On my commuter; I run a 52/40 at the front and currently a 34-14 7 speed freewheel on the back. I have ordered a 25-13 7 speed freewheel from an ebay vendor, which will get installed next weekend. Recently, I have been riding as if I have a six speed 24-14 freewheel (just not using the 34T cog at the back); and that is working nicely. The jump from the 34T to 24T is murder on my knees.

If you want to get crazy; you could get one of these: http://www.amazon.com/Nashbar-Carbon...7769349&sr=1-6 which would take a could of pounds off your bike......personally, I would not.

Please keep up the reports.