Review on Enhanced Performance with EC90 Carbon Fiber Bike Seat Post - 3K Seatpost for MTB Road & Mountain Bikes Cycling by Kyle Bonnell

Two of these seat posts broke despite careful assembly and little use (only asphalted neighboring roads). I now feel compelled to leave this review as a warning to others. Seatpost #1: About 50 miles after installation I noticed a vertical crack near the seatpost clamp. I was careful when installing using a torque wrench and fiber gel to avoid doing just that, but I had to guess what torque to use as the EC90 doesn't offer recommended torque specs. So I decided to go with the EC90, assuming I was just applying too much torque, and ordered a different seatpost. Second seatpost: This time I used less than 4Nm of torque on installation, but actually <100 miles later the seatpost** broke in half while driving through the nearby cobbled roads**. At the moment I don't have enough confidence to try a third seatpost and would prefer a refund instead. I'll update this review to show how well (or badly) EC90's customer support handles this.