One of the trends among high-end carbon bicycle frames is the integrated seatpost. In general, this means that the seat tube extends above the top tube to just below saddle height, and the saddle itself attaches to a stub post or a clamp gripping the top of the seat tube. Scott, Giant, Trek, and others all have top level road bikes with integrated seatposts, but LOOK Cycle takes a different approach.
Their system is called the E-post, and Look designed it to not only take advantage of the weight reduction and aesthetic possibilities of an integrated post, but to also provide a way to further tune ride qualities for the individual rider.
An integrated seatpost works well for carbon when the design can eliminate the need for a strong collar on the seat tube just above the top tube. Carbon as a rule doesn’t take to highly concentrated stresses such as that. However, most integrated seatpost designs still require a fair bit of strength on the seatmast (the part of the seat tube above top tube of said integrated seatpost frames) because the saddle cradle must adequately grip the top to maintain saddle height without slipping.
LOOK beats this by designing the E-post to slip into the cut seatmast. A small tension bolt accessed from the top of the E-post expands a set of elastomers inside of the seatmast. Relatively little force is necessary to affix the E-post since the top of the seatmast directly shoulders the E-post, preventing slipping. Small height changes can be made by adding spacers onto the shaft of the E-post before slipping it into the seatmast. Not only that, but the shoulder of the E-post is itself an elastomer that can be exchanged for a different hardness. In effect, the rider’s weight rests on that elastomer, and changing the elastomer will change how the rider perceives the road vibration.
It’s a clever system that works well. However, just like all other integrated seatpost designs, one would do well to not cut off too much from the seatmast. There is a limit to how many spacers can used to raise the saddle height (30mm), and you can’t add length to the seatmast once you cut it. Another troublesome aspect is trying to put the frame into a workstand. Since most workstands grab the seatpost, you are in danger of crushing the lightly built seatmast. LOOK’s E-post is more tolerant of workstand clamps so long as the clamp works on a screw-type closure (like Ultimate workstands) rather than a lever-actuated cam (like Park). Of course, workstands that grip the bike at the fork tips and bottom bracket avoid this problem altogether.
The LOOK E-post works only with their road frames such as the 595 and 586, the stunning new 596 tt/triathlon frame, and the 986 hardtail mtb. The E-post is available in several offsets for the saddle cradle and is reverse-able front to back. Available in the US through LOOK Cycle USA.
Clockwise from right: 1) Look E-post 2) expanding elastomer 3) Interchangeable elastomers in soft grey and firm black 4) spacers for raising the saddle height.