Compatible? I’ve seen a great deal on a third party crankset and bottom bracket. However, it’s from a 2021 model owner and my bike is a 2002.

How big is it? 50t or 54t?

I know the Shimano SM-BBR60 fits on the Brompton. I’m not sure what BB is pictured there. I ran a similar setup on my Brompton so it should work but you should get the item listing for exact specs. Depending on the spindle length you might need some shims for the BB.

I actually have an extra set of similar cranks that are new (I was going to put it on another bike but I ended up getting even lighter ones). If anyone is interested I’m in London.