I have the Topeak Beam Rack (V-Type). I don't think you'd be locked into a Topeak bag. The track is below the bars on the rack so a normal bag would sit on the bars and just be strapped down I would assume. Worrying about the weight thing would get annoying. I'm thinking about just putting the explorer rack on my Hybrid and finding a used road bike for the fitness and weekend rides I want to do