+1. I consider about 10 miles a minimum, and my current early morning commute is a minimal 14 miles one way in the reverse usual commuter route, and in the past was 11 miles. Currently though since my accident, I had to make promises not to commute at night, so it is only one way, but better IMO than two separate seven mile rides. In fact, a one way commute is quite pleasant, with a train ride home in the reverse usual commuter direction in a nearly empty rail car, and eliminates the drudge component of riding home after a full day’s work, in denser traffic.

In the nice weather I engage a training schedule with daily mileage quotas, and can expand the inbound distance gradually up to 30 miles one way, through some premier cycling areas of Metro Boston.