LOOK 2009 Launch: part 2, The E-post

e-post%2001.jpg 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.

e-post%2002.jpg 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.



7 Comments

Clever idea—but the post makes it sound like the Trek post has the limitations of traditional integrated seatposts.  I think the Look solution LOOKS nicer—but the Trek is probably cheaper to implement and more flexible. 

I think right now Trek still has the best integrated post solution.

While the Trek “seatmast cap” is nice in that it doesn’t require cutting the seatmast, the LOOK E-post edges it on options.

The 3 models offer 5mm reversible,  32mm reversible, or 15-45mm continuous rear offset.  The first two have continuous tilt adjustment, the last is micro-adjust. 

Carbon damps vibration, but not as much as an elastomer.  Plus the rider can choose the elastomer.

I haven’t ridden the E-post enough to decide whether the height adjustment by spacers would be handy or an annoyance. I can feel a 1mm change in saddle height, but LOOK includes a 1mm spacer.  Besides, after 30min my pedal stroke adapts so long as it’s not off by more than 3mm from my normal saddle height.

To me, the Trek design is an integrated seatpost that looks nice and eliminates most of the headaches of other designs, but the Look E-post explores the possibilities of integrated seatposts. It’s possible that the Trek design is lighter or places the weight lower than the LOOK E-post, but I don’t have enough data to determine that.

LOOK Cycles lent me a 595 to ride while I was in Los Gatos.  Check back later for my impressions on the bike and the E-post.

There are issues with Trek’s clamp slipping.

And today Voight’s seat fell off his Cervelo seat mast, but as Frank at TDF Blog said, “I think he squeezed it right off with his powerful butt cheeks.”

I think the Trek comes in 2 lengths and 3 offset (20, 5 & -10mm) options.  My experience with Trek mast is pretty limited, and luckily the people I know riding the new Madones haven’t had slipping issues.

The Look solution does look impressive.  I just wanted to point out that other manufacturers were also trying to tackle the integrated seatpost problem… especially since Trek was lumped in with those using traditional integrated seatpost methods in the original entry.

The Madone slippage issue isn’t with the post slipping down, but with the single-bolt clamp mechanism.  If you are on the nose of your saddle and hit a bump - it may drop the nose.  They suggest 17Nm of torque on that single bolt, but even still it can slip.  I’ve solved that problem (happened to me 3 times) with some carbon prep on the hemispheres that make up the attachment mechanism.  It’s a little hard to setup because once the prep is on - making small adjustments can be a challenge, but once you get it right, it won’t budge.  I can ride it with the bolt removed!  To free it back up I had to poke the part out from the offside with an allen key.

I’ve had a LOOK595Ultra since they first came out (2007) so I have the earlier spacer design.  It’s great except the red (softer) spacers don’t last very long and so far have been impossible to find replacements for.  I understand the next generation frame solved this problem.  However, the old and new spacer designs are not interchangeable so you can’t replace the old spacers with the new ones.

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