I agree, but the "affixing mechanism" is an integral part of the saddle. More so on the Brooks B135 than on other saddles because the Brooks uses a "double rail" design that MUST use the Brooks clamp. You can't just put this saddle on a standard "micro-adjust" seat post (without aftermarket adapters). As [MENTION=20397]cale[/MENTION] says, a straight seat-post is required with the taper to 1" where the saddle is mounted. Since the clamp is not only part of the saddle, but also is supplied by Brooks, I consider them a single integrated unit. Therefore a clamp failure, at least in this case, is a "saddle failure."

I further posted because having a saddle rapidly and unexpectedly change angle to a significant degree while riding can be a safety hazard. I was fortunate that in all cases, my Brooks B135 tilted but slightly and then stopped, but make no mistake - it could have been worse! The situation is exacerbated by the fact that Brooks specifically recommends the B135 for riders of over 200 pounds. These are the riders for whom the factory clamp is most likely to be inadequate.

IMHO, Brooks should redesign the clamp of the B135 with a larger through-bolt and larger nuts to avoid this type of failure. The factory 13mm clamp nuts are inadequate for the recommended riders. That said, lighter riders are unlikely to have this problem.