bikerumor monday mystery pic from first flight bicycles

Photo from the collection of Jeff Archer of First Flight Bicycles. If you think you know what this is, post your answer in the ‘comments’ section– the correct answer will be posted there on Tuesday!

To send in your own Mystery Pic to be considered for the Monday feature, click here and attach your photo with all pertinent information.


  1. Prototype one-bolt seatpost, but there are some details that don’t look quite right about the cradle.
    On the upper part of the cradle, where I would expect a corresponding valley for the saddle rails, there’s a bump, which doesn’t make too much sense.
    On the lower, there seems to be a vertical guide rail for the upper (to prevent twisting?) , which seems a bit odd also, as you get vertical alignment from the saddle rails themselves for free.

What do you think?