Crankbrothers Kronolog Adjustable Seatpost

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by Brandon Turman

This past March, Crank Brothers introduced the Kronolog, an all-new adjustable seatpost based around a simple mechanical design concept - that of a bar clamp. The post boasts 125mm of infinite adjustment, comes in 30.9 or 31.6mm diameters, and weighs an impressively light 493 grams with the remote. If you're unfamiliar with the inner workings of the post, take a moment to revisit this "First Look" feature that we prepared when the post was first launched:

As you can tell by watching that slideshow, when we first got our hands on it we were pretty impressed. Everything from the fixed cable routing to the lack of side-to-side play were notable improvements over most of the posts available at the time. Several months and dozens of rides later, we're here to report our long term findings.

Things We Love

Ease Of Installation

Installation is quite simple and straightforward, provided you take your time. As stressed by Crank Brothers, it's absolutely crucial that there's a bit of play at the lever, and that the cable housing is able to move freely where it enters the post. This is necessary to prevent accidental engagements or, in some cases, slippage. Spending a few extra moments to ensure this is done correctly may save you some headache later on. Crank Brothers graciously installed the post for us initially, but we've since swapped the post around various bikes over the past few months with no issues. On that note, we must commend Crank Brothers for making one of the easiest clamp head mechanisms we've ever used. Switching saddles is usually a major pain in the butt, but not with this system.

Narrow, Versatile Remote Lever

The narrow profile of remote lever is great. Too many remotes are wide and bulky, using up valuable bar space. The remote is also incredibly easy to move around to fit different bike configurations or preferences (top/bottom/left/right mounting positions). Most of the time we've spent on the post has been on a bike with 1x10 gearing, so the remote has been mounted where the front shifter normally is. In this position, the lever is very easy to reach with a thumb while not compromising grip on the bars. In addition, the cable housing exits the remote at a good angle for keeping things clean and tidy up front.

On The Trail

We've also grown to love some of the post's key features while on the trail. When the lever is depressed and the post comes up, the rebound speed slows down at top of the stroke. Thanks for looking out for our boys, Crank Brothers. Not content with just two or three fixed positions, the ability to stop the post at any height level is great, especially for a mechanical post. What's even better, though, is the stationary cable. Having snagged a few seatpost cable housings on linkages and shoes, the fact that the cable doesn't move with this system is one of the biggest highlights for us. This also quiets the bike, prevents unsightly cable rub, and lightens everything just a tad more due to the shorter cable length required.

This post is silent and jiggle-free in all positions, which is huge for anyone who appreciates a quiet bike.

We agree with Crank Brothers when they say that the post has a comparable feel to some hydraulic posts, but the action isn't quite as smooth as some of the current high-end hydraulic models. It's close, though.

Long Term Wins

After several months of use in mostly dry, dusty terrain, the main seal seems to be intact, the post has maintained air pressure, and there is still zero side-to-side play.

Things That Could Be Better

Heads Up For Short Riders

As noted in our "First Look" feature, the overall height of the post is a full inch greater than the RockShox Reverb. Shorter riders should be aware of this. If the distance between the top of your seat clamp and the center of your seat rails measures less than 8.75 inches, you'll need to install a spacer internally, which will reduce the amount of travel.

Remote Lever Nuances

There are a few small areas for concern when it comes to the remote lever. First and foremost, the Kronolog requires more thumb pressure to actuate than most of its competitors. We found this to be especially true after being seated for long periods of time or over rough terrain, which causes the post's locking plates to jam up slightly. This could be aided by lengthening the lever slightly, increasing its leverage.

Second, when the remote is depressed fully, the cable is pulled in such a way that it actually makes a sharp bend where it leaves the barrel adjuster. This throws up a few red flags - one for added lever resistance as mentioned above, one for premature cable wear, and another for the possibility of a worn barrel adjuster.

Finally, the clever Crank Brothers logo portion of the lever is quite thin. When rubbed against our hand repeatedly it actually wore a few holes in our skin. Ouch.

Over Time It Slows

After a few months of use, the post's rebound speed slowed down noticeably. Curious, we verified that the air pressure hadn't changed since we initially set up the post. Per Crank Brothers' recommendation, we applied some TriFlow lubricant to the area under the dust cap, between the locking plates. This revived most of the post's original liveliness, but it still doesn't rebound like it once did. To the their credit, it was incredibly easy to service the post in this manner. One bandaid solution to this problem is to simply increase the air pressure, but unfortunately that make the post more difficult to push down.

When asked about this particular issue, Crank Brothers said they've already made some slight tolerance changes to the bushings on new posts, which should allow more grease to pass through and alleviate the stiction problem.

Long Term Concerns

The wear on the silver slider plates shown above should be plainly obvious. What was once a neat array of laser etched markings is now a major area of concern (to us, at least). Noting the raised ridges above most of the smoothed out portions, it's clear that the majority of the metal deformation occurs when the locking plates engage while the post is being pushed down. Simply put, the locking plates are digging into the post every time we lower the saddle, sometimes worse than others. The raised ridges are an issue for a few reasons - they likely wear the seal and bushing at a much faster rate, they cause a "notchy" sensation when using the post, and the diameter of the post is changing a very, very small amount every time this happens. Our big concern is about the post slipping during use due to the deformation.

During a phone call, however, Crank Brothers assured us this wasn't an issue during their tests. "We're confident that the wearing of the grooves is natural deformation that will not impact the performance. The grooves are all about cosmetics, and based on all the testing we've done, it hasn't had any long term effects."

While riding, our post will occasionally creep down about 2 to 4mm. We're unsure if the deformed metal is to blame, or if the internal locking mechanism is just "settling in" each time.

Crank Brothers also stressed that "it's necessary to unweight the saddle completely before depressing the lever." Admittedly, we don't. Old habits die hard and that's not how we're accustomed to using a dropper post. Last second terrain changes often require fast reflexes to lower the post in time for descents or technical sections, and there often isn't time to stand up and then sit down. If you don't unweight the saddle each time, a very small amount of wear will occur when it unlocks. A similar issue arises if the lever isn't fully pressed before motion occurs.

Future Changes?

Curious if anything was being done to address some of these issues at the production level, we asked Crank Brothers what their plans are for the Kronolog in the near future:

"Generally speaking, the updates are centered around making setup more intuitive so that a rider knows without question that their post is setup correctly. The functionality and fundamental design of the post isn't changing. We put the Kronolog through extensive machine and ride testing so that we could have total confidence in the product prior to its release. The Kronolog survived thousands of hours of testing with no problems prior to release. During our thousands of hours of testing, we always setup the remotes and cable housing perfectly. Now that the Kronolog has been released to the market, we are learning that an improper setup can cause premature wear, so we are doing everything we can to ensure that the Kronolog gets setup correctly each and every time. We take full responsibility for riders setting up the seatpost properly, which is why it is so important to us to make setup more intuitive."

What's The Bottom Line?

On paper, the Crank Brothers Kronolog is a very impressive adjustable seatpost - its long list of features reads like all the best features of all the top competitor posts combined. Where the Kronolog falls short, however, is inherent in its design. Much like the simple bar clamp it's modeled after, we fear that long term wear will render many posts completely unusable. We're hoping a few minor material changes are in the plans for future updates, which could greatly extend the life of the Kronolog.

About The Reviewer

Brandon Turman likes to pop off the little bonus lines on the sides of the trail, get aggressive when he's in tune with a bike, and to really mash on the pedals and open it up when pointed downhill. His perfect trail has a good mix of flow, tech, and balls-to-the-wall speed. He loves little transfers, rollers, and the occasional gap that gives him that momentary stomach in your throat kind of feeling. Toss in some rocky bits with the option to double over them or risk pinch flatting and you've got a winner in his book. In 13 years of riding he worked his way through the Collegiate downhill ranks to the Pro level. After finishing up his mechanical engineering degree, his riding focus turned to dirt sculpting and jumping with the occasional slopestyle contest thrown in for fun. Nowadays he's Vital MTB's resident product guy.