I have three bikes, my Masi is on the trainer for indoor use; my Cervelo RS is for recreation and my Marin 29er is my commuter bike. My commute is a wimpy 1.6 miles, but I can go home for lunch and get 6.4 miles out of my daily commute. I roll out of my drive way and hit the main road after about .3 miles of pedaling. The main road is a three lane, with a turning lane down the middle. The road is wide enough for me to ride near the white line and avoid traffic. There is no shoulder, but because of the turning lane, cars usually slip over into the turning lane and give me plenty of room. There is no on the road parking, so I do not have to worry about being doored. I do have to watch for debris, usually in the form of collected leaves or small tree limbs. If necessary I could roll into the gutter or even jump the curb. Jumping the curb has not been necessary and I only rolled into the gutter a time or two to see how it would work. I watch the cars behind me with my mirror. I have a bright head light and three tail lights. I run my lights day and night. I always wear a helmet. At sixty I don’t want to learn my ABCs again. The last leg of my commute is across a university campus, my place of employment. I watch for golf carts and student drivers.
If I had it to do over again, I would have bought a touring bike for my commuter bike. The Marin 29er is a very good bike, but it is heavy (33 lbs with the knobby tires). I replaced the knobby tires with Schwalbe 32cm. I think a good steel frame touring bike with 28cm tires would be the ideal ride for my commute. A Reynolds 953 or 853 frame could be as much at 10 lbs lighter. Since my commute is so short, the 29er works fine, but I would like to use my bike for longer rides around town. And, since I am accustom to riding the Cervelo, I don’t want to slow down too much. I am wondering if 25cm tires for the Cervelo would make it an adequate commuter bike?