I've been a "roadie" for two years now and only recently started riding fixed as well. I've found that while I find it super fun to ride, I tend to get very lazy with my cadence/speed on false flats or slight headwinds. I have to be conscious about it or else I just end up going at a leisurely speed. (which isn't a bad thing for a chance of pace from the roadie). I'm riding 48-18, thought about going lower but I'll just tough it out and work on my strength.