Supposedly, from Instagram, an issue of some kind with the gears on Amy's bike. Rather odd, in that the bikes were serviced on arrival, so you'd think the mechanic who did it would have notied such a fundamental problem :-\ Also odd that it's taken eight hours to not fix, so far. It's hard to imagine what would be so problematic on a mechanical system for which they have spares themselves, even if the bike shop doesn't.