What if there was a dropper post that solves and not just improves reliability issues, saves cost and time, and does not let you worry about time at service centers anymore? Or how about 'bleeding' your seat post within a few seconds while it's still installed in your bike?
BikeYoke presents its new REVIVE dropper post featuring one of the most brilliant design features in dropper design in many years. Revive will start with 125mm and 160mm options, infinitely adjustable travel and in 30.9 and 31.6mm diameters. More than ten years of experience in dropper design went into the Revive, and the development has finally paid off. Of course, just as many other companies BikeYoke would say, that Revive is reliable, strong and smooth…
And yes, Revive is all of that, but not because we tried to improve current designs, but because we were thinking outside of the box and created a new concept, that is different from everything before.Status Quo
To understand the benefits over other posts, you have to know about the problems of many current designs first. Many of the traditional current designs are based on a hydraulic lockout-system that relies on a perfectly sealing IFP (Internal Floating Piston), separating oil from air to prevent the seatpost from getting that suspension feeling. There are a lot of difficulties to overcome when using an IFP because an IFP has to maintain 100% sealing function. If air can go to the oil side, your post will start becoming springy. This happens to a lot of posts on the market already and is the main issue why they need servicing. Just to mention a few of the issues an IFP design comes with:
• An IFP design requires a perfect finished surface of ID and OD, of both, inner and outer tubes in the hydraulic circuit. There is a high defective rate during production and is also difficult to keep the quality stable. This means those tubes are very expensive to produce.
• IFP designs require perfect concentricity of those tubes to ensure the IFP can move smoothly.
• An IFP is a dynamic seal with high preload/squeeze. This causes a 'stick-slick' effect on many posts, which you can feel, when your seatpost gets stuck and you need to break it loose manually because only pushing the remote won't make it start moving.
• IFP's are usually kept as short as possible to save on build height. But this means they can tilt inside the tube more easily and cause overly extensive wear and/or leakage. Long tubes and long travel will make it worse because the IFP has to follow not a straight line inside the tube, but a bent tube, since longer seatposts will obviously have more flex.
• An IFP usually requires a complex or difficult bleeding procedure, where the IFP has to be set to a certain position. Too much or too little oil also can cause malfunction of the seatpost.REVIVE Design
This is why BikeYoke's Revive features a non-IFP design because we think it is too difficult – if not impossible – to make a reliable design using an IFP.
The Revive only requires two dynamic seals in the hydraulic circuit (RS Reverb, KS LEV and Fox Transfer use four dynamic seals) with those two seals being the ones that are known to cause the least problems in sealing application: The inner shaft sealing and the piston sealing for the lockout mechanism. The highly critical IFP is removed and with it the need of perfect concentricity and finish of the sealing surfaces of the tubes. The lack of an IFP also results in the smoothest action of any hydraulic drop-post on the market. REVIVE VALVE – The Reset-Feature
Even Revive can get air somewhere where it does not belong. This can happen for example, when you actuate your seatpost for a few times, while its upside down. And here is where the patented Revive Reset Valve comes into play: The Revive valve is located underneath the seatpost-head (same as a Reverb and KS LEV for example) and serves as regular air-valve for pumping up the post. However, pushing the Revive valve opens ports between chambers and activates the Revive-function:
Insert a 4mm Hex Key into the Revive hex port, turn it and push down the post by hand. This will automatically reset your hydraulic circuit to “new.” Whenever. Wherever. This can be done within a few seconds and only by the turn of a 4mm Allen key, without even having to remove your dropper post from your bike.
We made a video to show how simple this is:
One Piece Lower
Next to creating a completely resettable hydraulic system, Revive also features a one piece lower tube, whereas many posts have the upper bushing (which experiences the biggest load) installed on a separate top cap, which is threaded on top of the lower tube. Installing the upper bushing directly into the lower tube does not only increase the structural strength of the lower assembly but also provides better load displacement. Perfect concentricity with the lower tube and it's keyways that house 6x pins to eliminate rotational play, is also an attribute that comes in hand with a one piece lower tube. Due to the extra wall thickness at the collar area, Revive is also less prone to be affected by high seat-clamp squeeze. Serviceability
So, now one might already understand that:
1. No air will want to go inside the post's hydraulic circuit since it's charged with higher pressure than its surroundings.
2. No oil will go out (or at least very very little oil over the course of a long time) because of very stable sealing - external sealing has never been a real problem of current post design
3. The hydraulic system can be reset to “new” via the unique “Revive-valving.”
This makes the hydraulic circuit into a stable closed system and basically maintenance free. Still, there are parts that need to servicing sooner or later and when designing Revive we put a lot of attention to maximum user-friendly serviceability: Bushings and keyway pins will wear over time. Usually, the pins wear first, and you would want to replace them to reset your rotational play. Exchanging the pins and the lower bushing is simple and does not require any opening of the hydraulic system and can be done within less than 5 minutes. You can watch how to do a full service here