Not in a part of ebay that folks here typically trawl, but this is actual cycling memoribilia...
... with a serious twist. Please see item # 6624579772
Probably a British club cyclist or club follower from Kent, stuck in a trench in WW I, with nothing to do but create. And so we end up with:
WW1 TRENCH ART: 1908 GERMAN SHELL KENT CYCLIST BADGE
Yup, a German shell manufactured in 1908, fired in anger, and subsequently tweaked.
I'd make a "bike boom" joke here, but should probably head to bed instead.
Dan Kehew
Davis, CA