Beautiful hunks of machined, polished stainless steel, looks like they'd have a Vulcan death grip on my seatpost. But on the last epic ride my wife and I did yesterday, hers had slipped 3" by the end of the ride, mine 2"...Here's the story: Had a 410mm length 27.2mm diameter Thompson Elite in my D440's frame. Found out it was 0.2mm oversized for my D440 frame, which actually has a 27.0mm diameter seat tube. No wonder it was so hard to get that sucker down the seat tube! It never slipped, that's for sure. Anyway, my wife needed a longer seatpost than her stock one, Jensen had the 27.0mm ones on clearance (discontinued size, if anyone needs one, get it now) so I got one for my bike, transposed mine to hers, which has a 27.2mm seatpost. Got another Surly seatpost clamp at the same time. Now, BOTH of our seatposts are slipping. I don't have a torque wrench, but I know when it's snug enough. They were snug enough. So, now I've really torqued now on 'em, more than I like. If they slip again, something's wrong here. I'm using the 30mm Surly ring, and they fit the seat tubes correctly. Anyone have recommendations for another seatpost clamp, or are Thompson seatposts 'small for their size'? Thanks in advance to anyone who's had experience with this combo.