Imlach's Sweaty Hippie Funk Collection, adventure bikes, rusty rats, cruisers and other alt bastardisations of bicyclery
That's a good point, a very skewed chainline can make the chain kind of knot up when backpedalling. But I don't see why it'd be tight when no rotation and then sloppy once he begins pedalling
grey-beard
Orange 🍊 Fan
Chain line is spot on. I'm still suspecting that BMX chainring. It's a single bolt fixing and I reckon there's play in it. So it's isn't perfectly central on the bottom bracket.
About a ring being out of round, it's quite rare that chainrings aren't a bit out of round, so it isn't something I'd worry about. It's just important to set the chain tension on the tightest spot, but what you're describing sounds like a completely different symptom and I'm scratching my head.
grey-beard
Orange 🍊 Fan
It turns out that I am missing a part?
One of these
https://alansbmx.com/collections/bm...s/crank-top-hat-washer?variant=39777639235682The chainring has a 23.8mm hole to fit over a 19mm axle, so you need an adapter, obvs.
Guinessisgoodforyou
rBotM Winner
That is stunning. Bar a few detail changes for my taste 
