Pretty much what I was going to say. Adding a rack & upsizing tires will change the feel of the bike. I commuted with a back pack, for a few years, on road bikes. There's no need in changing the bike.
Originally Posted by tjspiel
When riding aggressively, I always put the backpack on my back, but when riding on pavement, no off road, I prefer to have it tied to the rack, off my back. I guess Scott will feel like the Mule with drop bars, perhaps just a little lighter (and with nicer gearing), and more aero.
Originally Posted by lostarchitect
I must admit that Tsl's picture of his bike with winter tyres in the snow has made me start considering that setup. Plus the fact that I miss most group rides since I couldn't carry riding clothes to work on the road bike - this will make that possible too (group rides start from the City, while I live 11 km away in the suburbs).