I plan on commuting to work in 2011, 2 days a week. My round trip commute will be about 35 miles. I will use my Giant OCR 3W. Should I switch out the tires to more of a cross tire or ??? I work at a hospital in the operating room, so I will be able to wear cycling clothes, have access to a shower. The only essentials I need to carry, ID, cell phone, keys, maybe a lunch, and lock. My bike will be locked outside to a bike rack(visible to security), not visible to the public. Any thoughts, recommendations? How should I train for commuting, should I be able to maintain a certain speed or just ride for distance? Thanks, I appreciate your feedback(input).