Originally Posted by arbee

At least it's new to me. Riding around, I scanned Citibike docks when I passed 'em and I saw no clamps like this. In the past, when Citibike introduced something (e.g.: the plastic cargo tray) and they wanted comments from users, they sent a follow-up email. Thus far: silence.

Quick summary — This clamp is an excellent example of "If it ain't broke, don't fix it".

A few details — Not clearly evident in my one pic: there's a knurled adjustment opposite my position at the rear partly hidden by the seatpost. There are cams on both sides of the clamp. From my one experience: for the clamp to tighten smoothly, both cams must be closely in synch. Casually actuating the clamp: it doesn't tighten smoothly. That said, helping out at various bike clinics over the years, I've been surprised at how many folks don't find the conventional clamp handle to be intuitive. Maybe this will help some users.