Originally Posted by
531phile
Cyclocross will be a tad slower and you'll get more of a workout, maybe add about 10-15 mins to the commute...
I would not get anything bigger than 700 x 32. Too much rotational weight means more effort and a slower ride especially starting up from stop signs/lights.
This is probably a bit high. It's unlikely that a crosser would be 2kg heavier than a road bike of the same price, and adding 2kg to a road bike - on the frame or rims - adds only about 2 minutes to a 50 minute
mountain stage climb:
http://www.training4cyclists.com/how...on-alpe-dhuez/
On the flat the difference - of any - will be MUCH smaller. I'd predict a crosser and a road bike to take the same commute time if rider position is the same.