With their background in designing suspension and valving internals for some of the big bike companies, the design engineers behind BikeYoke have come back with an actually unique and innovative solution to the dropper seatpost problem. It was a not so subtle hint that they had a dropper post in the works after releasing a couple of better designed remote levers this summer.

But they had been holding off on the big reveal of their dropper that uses a different hydraulic lockout design that eliminates most of the pitfalls of the currently standard Internal Floating Piston layout. Their design allows you to on-the-fly bleed off any air that gets where it shouldn’t be (the most often reason to need for a dropper rebuild), and allows for easy servicing of bushings and guide pins (anti-rotating) at home without opening the hydraulics. Take a closer look, and we’ll try to explain why this is kind of a big deal…

As a little primer as to why BikeYoke went for this different design it helps to explain what the status quo is. Most dropper seatposts use a similar tech solution to sliding up and down and locking in place, relying on a very precise Internal Floating Piston (IFP) that must be perfectly sealed of subject to failure, keeping oil & air separate. When they don’t stay totally sealed, air gets in and your post bounces up and down like a suspension post, necessitating a rebuild, one of droppers’ biggest issues.

Now that level of precision is tough, and requires tight inside and outside tolerances and finishes without imperfection that keep costs high. It also requires tight dynamic seals which often result in stiction in the post, needing to be helped up again.

So to combat that BikeYoke dropped the IFP design all together for their Revive. Instead they went with a design that is more simple, and lets excess air bleed into the shaft instead of into the oil. That means that production is a bit easier, and by incorporating a bleed valve in the head of the post, when air goes where it shouldn’t, and you post gets squishy, you can bleed it out in a couple of seconds tool-free. An added benefit is that they were able to use just 2 dynamic seals, for super smooth movement and no friction sticking, and still get a hydraulic setup that is more stable and longer lasting.

BikeYoke_Revive-alternative-hydraulic-lockout-dropper-seatpost_american-wire

The key feature is of course that Revive valve, or reset button on the head. Press it, and drop the post by hand and the hydraulic circuit is totally reset. Back to good as new without having to even take the dropper off the bike.

The Revive also builds in a bit more strength/stiffness by mounting the upper bushing right to the lower tube instead of an add-on cap for better performance with the same stack height. The one-piece lower tube also lends better alignment for the 6 keyed pins that keep the post from rotating.

Still, it is a dropper, so it will need some service over time. But BikeYoke has designed the Revive so that the bushings and keyway pins that will wear out with use are as user-serviceable as possible. They can both be swapped out without messing with the hydraulics and can be done by anyone who can operate a set of retaining ring pliers in about 5-10 minutes.

BikeYoke_Revive-alternative-hydraulic-lockout-dropper-seatpost_head BikeYoke_Revive-alternative-hydraulic-lockout-dropper-seatpost_slider BikeYoke_Revive-alternative-hydraulic-lockout-dropper-seatpost_insert

The Revive dropper post will come in two travel lengths, 125 & 160mm, and in two seatpost diameters for each travel: 30.9 & 31.6mm. They can be operated by either a 1x specific remote like BikeYoke’s Triggy that takes the place of a left shifter, or an old-style up/down push button remote.

The 125mm dropper in 30.9mm diameter is claimed to weigh 470g, while the remote without cables adds another 25g.

BikeYoke_Revive-alternative-hydraulic-lockout-dropper-seatpost_sizing BikeYoke_Revive-alternative-hydraulic-lockout-dropper-seatpost_overall

BikeYoke’s Revive dropper post is slated to be available in January/February 2017, in time for early spring riding. They will be offering a pre-order deal that will open up just after Eurobike in a couple of weeks that will run throughout the month of September. Anyone who pre-orders then will lock-in a post for the beginning of the year delivery and is said to expect some freebies thrown in with their order. Pricing on the pre-order has been set at 350€ for the 125mm travel version and 370€ for the longer 160mm version. Both prices include a Triggy remote, a free I-Spec adapter or Shifty SRAM pulley, and an upgrade to ti saddle clamp bolts. They are also inclusive of German/EU VAT and free worldwide shipping.

BikeYoke.com

19 COMMENTS

  1. Maybe i’m missing something, but isn’t this air that you’re eventually bleeding out the same air needed to extend the post? So in essence your post could start returning very slowly or not at all if you have to bleed it too much during a ride?

    • You probably can’t do this during a ride unless it’s a large amount, as the agitation will cause oil/air mixing. you’re gonna want to let the air settle out of the oil before you bleed. If you’re having it happen multiple times during a ride, you’ve got bigger problems. This isn’t a operation you need to do very often, I’ve had a reverb for 6 months & it hasn’t needed a bleed yet, even though I’ve yanked on the seat hard enough to pull it out a few times.

  2. *yawn* When someone combines the spring mechanism of a Gravity Dropper with a locking mechanism of the 9point8, I’ll take notice. Until then, easily replaceable (and cheap) cartridges (ala Giant) or collet locking systems like Specialized CP IRCC (hold the seat even when seals fail) seem to be the way to go. Air requires seals, seals require bushings, and bushings wear out, taking seals and air with them. If we can remove the need for air inside the post, we can remove the seals and the reliance on the bushings, then all we need is a reliable way to hold the post up.

    • Or just buy a Gravity Dropper and forget it, how many more positions than Up, Down, Middle does a mountain bike actually need? GDs are light too, so even the weenies can’t argue.

      • I don’t know about the GD but I own a Forca with a similar system and I wish the middle position was slightly higher, 1 or 1.5cm., to be more useful.

  3. Comment section is a bit wonky today, so here are a couple of repsonses from Stefan of BikeYoke:
    @ Groghunter: You charge the spring just by a regular schrader valve, same as any other post.

    @ Ck: Of course, air will not get lost, it will just be internally relocated to where it belongs. No need to refill in any air after resetting.

    • Hah, I guess I was asking WHERE that shraeder valve is, since I don’t see it in the diagram. Up top like a reverb then I guess?

      • @ Marc: No it is not cheaper. 😉 Besides that, I think the Fall Line has the most promising design on the market. Well – maybe next to ours…

        @Paul: Can you tell me, how air is not a reliable way to drive a seatpost? And also, how a smoothly working post could ever go without bushings?

        • Bushings aren’t the problem. I can handle replacing bushings every couple of years. I don’t need smooth operation as long as its functioning as it should. Seals are what are the problem. As the bushings become worn, the seals get finicky, which allows air or oil to escape. If we didn’t have air or oil, we wouldn’t need seals, and our bushings could go for much longer maintenance intervals. When compared to cars, which needs replacing more often, springs or shocks? Does a dropper seatpost need the complexity of shocks when it could work just fine with springs?

        • Stefan, the solutions that BikeYoke are creating are awesome. The DeHy kits are fantastic. I just wish someone made a kit to turn a Reverb into a no-air neccesary spring supported dropper. Unfortunately the design is solely reliant on hydraulic locking. BTW I confused you with ICB 2.0 designer Stefan Stark.

  4. Still, 200€ for Giant dropper which has proven to be the most reliable post out there, and you’re set for at least 2 years. If anything breaks it will be covered under warranty and after that if anything goes wrong you can just get 30-40€ catridge which is so easy to install yourself.

    Reverb on the other hand is probably the worst and most hyped up modern post. Just small service costs as much as Giant’s new cartridge and when you need rebuild kit and not to mention special tools it’s going to get pricey!

    • @Marin : if Giant offered a 1x style trigger remote ala Specialized SLR, RF Turbine or KS Southpaw in its $300 retail price, along with a 31.6 post, I’d be all over it. The Giant is a great option as a OEM feature, but buying one new requires a few extra (and more expensive) steps to make it perfect.

      The Crank Brothers Highline would be perfect if the replacement cartridge didn’t cost $100 after the 3 year warranty period.

      • here’s a tip; buy and use an automotive strut from an autoparts store. make sure to measure it to get the correct size and use a 60NM strut for about 150lbs person. you may also have to remove some of the plastic housing on the strut. They are cheaper and work the same as the giant cartridges. I designed my own dropper post using one of these and a suspension seatpost I had lying around. I even made my own magnetic locking/ actuation system connected to an old shifter, works well!

  5. Giants cartridge is $60 plus in most remote places you can’t even see another giant dropper. This idea from a mechanical standpoint seems somewhat sound, what happens if the secret valve happens to go bad? How much is that going to run me. I have a KS now and looking for a new dropper for my hard tail, persuade me.

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