Pigeon pedal.

This is suprising, but I took the Feige out yesterday for a brief hour or two of plein-air painting. I picked a forested spot, and fussed with my watercolours, then rode home.  About half way home I started to note a shifting or notching sensation that occurred on my right crank, when it reached the apex of the pedalling, just before the downstroke.  

"Oh great." I thought, probably the cotter on the crank backing out or something un-wonderful with the bottom bracket.  It got me home, and I poked and prodded at the Pigeon, seeing if I could force in my hands, the same sensation. Eventually I took the pedal off (MKS 3000) and replaced it with the Union Platforms that came on Zwartehond.  I had to leave riding it for today. And when I did, the 'notching' sensation wasn't there.  Go fig, the problem is with the MKS pedal.