Thanks, neg prop wasn't me! and to all of you who fear injury from this design, they could use a boot or a cover or wrap the action around second top tube like on a cruiser, or a sleeve like they have for the elastomer on a softail.

I want to know why bb concentric is not used more, and why it is mostly used with single speed applications. What I have read so far alludes to torsional forces, no explicit mention of pedal bob. Does this imply that the chain line would steer the rear axle and main pivot so that the stays and rear hub are off track?

Yes, let's all ride, however, there is a viewpoint that some bikers or organizations are creating the wrong impression. This article might not state that clearly enough, it's not good for anyone if the negative perception continues. I can't control somebody's imagination, but I can conduct myself in ways that are widely recognized as positive. Because I don't want to ruin anybody else's fun.

I thought that I was riding only with males, more frequently all by myself, because I am not a good rider, and I work at inconvenient times.

POD = Pole of the day, hater

I love the video, but next time, try a Sam Adams or Berkshire Brewing Co. instead of a PBR.