Crank Brothers Kronolog adjustable height seatpost

We jumped the gun a bit on our original post about Crank Brothers’ new Kronolog adjustable height seat post. Since then, we’ve spoken with CB’s product development manager, Chad Peterson, to get the details.

Even they’ll admit the Joplin was an underperformer, which begged the question: What did they learn from it?

“We learned a lot!” Peterson says. “Actually, it’s a completely different body, damper… everything’s different except that it raises and lowers. The Joplin was actually something we licensed from Maverick. There were a few things we didn’t like about the design. It was good at the time, but there’s always room for improvement. When you pulled up on the saddle, it would raise up and everything would emulsify inside. We also wanted fewer moving parts, which means if there is a problem, it’s easier to identify. But it’s also less likely to have anything go wrong in the first place.”

Falling into their Iodine collection, the Kronolog features an entirely new design with some unique touches. First, the basics: It’s a mechanically controlled, air actuated infinitely adjustable post. What that means in lay terms is that it uses a cable to release the post rather than hydraulics, air pressure inside the tube moves it back up and there are no preset positions between full up or down.

Now for the details…

The Kronolog has a new, proprietary locking mechanism that locks the post into place for both upward and downward movement. Push down or pull up on your saddle and it shouldn’t move unless you’re also depressing the thumb lever.

Crank Brothers Kronolog adjustable height seatpost jam plate tech detail
Lines point to cable stop positions, but stops are not in place on this early prototype.


On the non-telescoping section of post, a standard shifter cable enters the bottom of the control section, leaves the housing in a lower Jam Plate and is fixed into the upper Jam Plate. When the release lever is pushed, the cable pulls both plates toward each other so they become parallel and release the inner post, as shown in this photo held “open” with a zip tie. In this position, the post is free to slide up or down. The jam plates encircle the post and clamp in the front and rear, one angle up, the other angled down. Since the arms are juxtaposed, each one works to prevent either upward or downward movement. Peterson says the design is patent pending.

One of the other unique features is their two-stage hydraulic air damping. To control the rate of drop and return, you simply adjust the air pressure via a Schrader valve (hello, shock pump!). To keep it from smacking you where the sun don’t shine, Crank Brothers gave it a central chamber that slows things down a bit before it tops out. During the last inch of upward travel, air pressure builds under the primary plunger and is forced through the small bypass opening, which damps the movement (aka “slows it down”).

“The Kronolog is unique in that it’s a combination mechanical/hydraulic post. Most mechanical posts aren’t infinitely adjustable, they have fixed stopping points. And, other mechanical posts don’t have any damping, so you can’t adjust the speed and force with which it aims upward at parts of your body you don’t want struck with speed and force.”

Eagle eyes will notice this design places the cable mech on the stationary lower part of the post, reducing the total cable length and keeping it reined in. Even better, you can position the cable entry point at the front or rear of the post for installation versatility. To attach the cable, a small cover slides down to access the fixing bolt.

The plunger itself is a single piston air spring, much like a bike pump, moving on Norglide bushings. The internal diagrams we’ve seen indicate a fair amount of overlap between the two tubes, which contributes to the robust strength claims. CB says it’s twice as strong as other dropper posts.

The post has a “unique keying system” between the quill and shaft that give it “substantially improved rotational stability.” It’s a head smackingly simple how-has-no one-thought-of-this-before design:

“We didn’t do a traditional key way like you see on other posts, including the old Joplin,” said Peterson. “We shaped the the sides of the telescoping post flat for a significant amount, more than 10mm on each side, and the front and back are rounded. It’s one of those ideas that’s very gratifying.”

Unlike small keyed sections, the broad flat surfaces are less likely to wear down and lead to play…rotation stability really is built into the larger design.

2012 2013 Crank Brothers Kronolog adjustable height dropper seat post with reversible thumb lever

It gets better. The thumb lever is easily swapped from left to right by simply removing the T-25 Torx bolt, flipping it over and threading the barrel adjuster into the other side. Brilliant. This also means you could easily mount it on the underside of your handlebar, helping you keep a good grip on the bar when the trail gets sketchy.

2012 2013 Crank Brothers Kronolog adjustable height dropper seat post

The new Kronolog has a few more tricks up its sleeve. For one, it’s about 50g lighter than its predecessor, coming in at a claimed 465g for the 30.9 post and 477g for the 31.6. The remote weight is 28g, putting the whole package right around 500g-ish, maybe a bit more with cable and housing.

Post length is 405mm and it has a 125mm (5″) travel adjustment range. Looking for shorter travel? No problem, you can add spacers in 20mm increments to shorten its range.

“Another unique thing about our post is the inner tube is 3D forged. Most posts have a bonded seat clamp fixed to the top of the telescoping section. We use (the forging) process on our Cobalt stem, as do a lot of other brands, because it’s much stronger, and it makes this post super strong. It passes EN standards at 2.7x the required fatigue testing, meaning our post can get OEM spec on bikes sold in Europe. The saddle clamping mechanism is identical to the one on our Cobalt Post.”

Crank Brothers Kronolog adjustable height seatpost

It’ll retail for $300 / €300 and come in Black/Red shown or Black/Black. Aftermarket color kits will be available in April for $45 to replace the anodized bits with either gold, blue or orange to match the rest of your Crank Brothers parts. Warranty is two years with proper maintenance, by which they mean wiping it down every few rides and applying a couple of drops of oil under the dust seal. They also recommend replacing the O-rings every 75-100 hours and an annual inspection of the seals, Jam Plates and bushings.

“It’s very simple, there’s not much to go wrong,” Peterson said. “Another benefit to this design is that we can adapt it to a 27.2 seat post, something no one else is doing in dropper posts. We’ve got that coming soon, but no ETA yet. It’s still in development.”


  1. First off – the Fox post will be rubbish. Overpriced and rubbish.

    Secondly, what have Crank Bros done to confirm that this post will be brought to market functioning as it should and continuing to function as it should? Having owned 3 different CB products (joplin, Iodine wheels and pedals) I’ve got to the point where I will NEVER buy their products again. Whilst they look fantastic, the quality of the products is far from acceptable. They’ve even accepted that the post was rubbish, which is great news if you’re one of the many that’s laid out some hard earned for one.

    Personally I’ll be giving this and any other CB product a wide berth. Sort your designs and QC….

  2. I guess I am not getting the jam plate execution. This has been used on bar clamps for woodworking forever but I am curious to see how this holds up.

  3. @Steve M

    bingo…how can a thumb actuated clamp generate enough clamping force to support a rider over trail impacts?

    perhaps surface treatments to add friction are part of the answer.

  4. Personally I would only consider this if CB would offer a trade-in from frustrated Joplin owners. I don’t know how other Joplin owners feel, but after the hours of my life I spent re-building my Joplin over and over, I hardly want to spend more cash for another CB product. The numerous times my Joplin when out, and how noticeable it is when it does fail, easily made the Joplin the most frustrating mtb product I’ve owned in 20+ years of riding.

    When I see how little issues and how easy the maintenance has been on several of my friends Reverb, I’m either getting a Reverb, a Fox, or trying that Blacx.

  5. I know that getting the bar clamps working is super difficult, the heat treatment of the steel has to be just right, soft enough to conform and grip, hard enough not to wear out. And this has to do it on aluminum?

    These pictures all look like renders to me rather than actual photos so I wonder if they even have a working prototype yet?

  6. They have prototypes. Their ‘athletes’ have been on them for a little while. IMHO, the prototypes feel like SH!T. They are very ‘stictiony’ and that lump where the cable enters makes for a very tall effective tube.

    I’m with the majority of the posters above, CB reputation precedes itself in terms of lack of quality and design integrity. I’ve tossed a Joplin post and Iodine wheels in the dumpster after too many failures. Look at the comments on the original post last week and you’ll see the same overwhelming experience.

    If you’re damn fool enough to think this time will be any different from these charlatans, then I have some swamp land in FL you may be interested in. The KS and RockShox posts are far superior to the CB anodized eye candy BS. FU CB.

  7. And Ted’s “FU CB” is an example of Ted’s sharp intellect and keen critical thought skills. He is the example to which all junior high kids should aspire.

    What’s important is how this seat post performs and holds up when it hits the market. Many companies have fixed QC and design problems in the past, and Crank Bros may very well do the same or have done the same. Time will tell.

  8. Wondering why you guys who don’t like this are getting so agitated. Back when Tom Ritchey and Gary Fisher still built mountain bikes, we just had a quick release on the seat collar. A whole bunch lighter than these >> 1 lb setups, works every time, put the seat up or down whenever you want. Methinks you are all over-thinking seatposts.

  9. The joplin 3 was a dog, the 4 is pretty decent if you clean it from time to time, my guess 3rd generation may be pretty nice. My mates with reverbs are really suffering. The fox wil be 1st gen and the Thompson is just a rumor. I’ll take 3rd generation.

  10. to those “defending” CB. (not many I notice)

    I have one CB product to mention.

    Cobalt Cranks.

    I lost track of how many broke in my town. And all the while CB refused (lied) to admit a problem.

    Then they just quietly disappeared from their website and range.

    FORM over function. (must be the CB motto)

  11. Seems shiny, but there’s nothing like my old good american Gravity Dropper.
    always works, minimal maintenance (in fact, I should say “zero maintenance”), fairly priced, and most of all reliable.

  12. When we bought 2 bikes our shop couldn’t get something else than Joplin in reasonable time.

    You don’t realize how we regret this. They are HORRIBLE.

    Seriously, one just leaks oil by sitting in the garage. And the worst is if you take your bike by the saddle it lifts up and doesn’t stay at its height ! How dangerous ! We will never buy another post from them.

    Part from the eggbeaters, I wouldn’t want anything from CB – sincerly.

  13. Great. I just bought a Joplin. Love my Candies so I thought it might be a good product. If the company admits they’re selling crap, but stand behind their products, is there an upgrade path to the not crap I spent my 200 bucks on?

  14. C’mom, seriously? CB should just get into making funky designs for cycling socks and staying far away from anything mechanical.
    Wait, let me rephrase that…. CB should just get into making funky designs for cycling socks and having a company that actually knows how to manufacture them properly AND being banned from EVER picking up a wrench or any tool that’s involved in making any component for anything.

    What a joke. These guys can’t be trusted, even with a video and a hundred diagrams showing all the things that will fail like every other part they’ve attempted to produce.

    Sorry, but I’ve been burned by CB too many times in the past and wasted a lot of money doing so. I wish nothing more than their exit from business and their impending financial failure.

  15. here’s the problem at Crank Brothers.
    Once upon a time, two cool designer guys (who we’ll call Carl and Frank) came up with a couple of cool designs.

    The Speed lever (still works to this day)

    and the original Egg Beater concept. (note that I did say concept)

    at some point after this, the two cool designer guys took on a new partner. (who we won’t name for fear of liable issues) He arrived with much marketing skill.

    They then expanded the range to many many variants of the same initial pedal design. But at no point did anyone put any real thought into the QUALITY CONTROL, MANUFACTURING or LONGEVITY of the pedals.

    Then they really expanded the pedal range. The marketing guy was very happy. The customers, less so.

    Then the marketing guy had a great idea. How cool would it be if “Crank” Brothers, made cranks?
    So after a hyped up product release at Interbike with all the industry media present, the Cobalt crank was born.

    And then they broke. (and CB denied any problem)
    And then more of them broke. (still they denied any issues)
    And still even more and more of them broke. (oh well, actually, we’ve had one or two they confess)

    and finally, without any fanfare this time, the cranks quietly were withdrawn from the website and the market.

    The new pedals have super duper bearings they say. Tested in water and everything they say. 3 months (or less) the pedals last. THREE DAMN MONTHS.

    Seriously, I have 1st generation Shimano Clipless SPD pedals from 1990 that still work fine. (beyond new cleats). Never been pulled apart.

    Wheels, geezus. Don’t get me started on the wheels. Crap bearings. Poor design. Explosive freewheel bodies. Week rims. And to top it of, THEY ARE ALWAYS OUT OF SPARE PARTS.

    To the CB supporters calling those of us with real history with the brand “haters”, please try to understand that we speak from experience. Much experience. Born of promises and claims that the CB marketing machine has proven itself incapable of delivering.

    And to those two original designers, to Carl and Frank that had a dream, I ask: Was the money worth it?

  16. CB sounds like they are in trouble with the buying public. Burn too many bridges and you won’t be able to cross back again….ever. Too bad , their “new” seatpost looks interesting and viable. Time will tell…..tic…toc…tic…toc !!!

  17. @ Teddy.
    there’re in trouble with more than just the buying public.

    They’ve managed to anger and piss off a large number of their international & domestic distributors with the lies, denials of poor design and refused warranty.

    Seriously, how many of you have 1st hand reports, (not someone that told someone that knew someone), but genuine 1st person reports, of people with a pedal axle spiked into their ankle because the bearings seized and the CB body unwound the end nut?

    I know of 6 on a personal level. (these are friends that I personally sold pedals to) One of them a magazine editor.

    Never, I repeat, NEVER again.

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