Hi. I'm a new member (who knows nothing about bikes) and just posted this question under "family/Recreation," but thought I'd post here as well. For a teen who's not a "bike rider" in the sense that she'll be using a bike mainly for riding around a college campus and weekend recreational rides of 10-20 miles, is the 7100 good or would you recommend spending an additional $80 for the 7200? Thanks for any advice.