Green Gear Cycling, aka Bike Friday, is a Eugene, OR company that long made the ideal city bike: the hyperfold Tikit, a built-to-order custom-frame folding bicycle that could be folded and unfolded in about two or three seconds each way -- and which, unlike the later models that replace it, could be built in a heavy-duty form for cyclists who aren't particularly light-of-frame. Owning one of these, of course, one is obliged to demonstrate that insanely fast fold/unfold process frequently. Alas, one of the parts involved in holding the stem against the frame when folded down was a piece of rubber threaded onto a screw with a flared-out end -- threads which eventually, after years of long and happy use, failed. Rather than try to recreate the exact part, I decided to try to model something stronger, with force spread over more surface area, and which didn't depend on threads to hold to keep the bike together; thus, what you see here.