Wireless technology comes to dropper posts with the new RockShox Reverb AXS. But can the performance advantages justify the high price tag?

>>> Best dropper posts in 2020

If you’ve not tried SRAM’s AXS suite of wireless components, it really is quite astonishing. Yes, we have become blasé to the incredible pace of technology and just what is available now at our fingertips, but the fact that SRAM has gone and replaced steel wires and hydraulic fluid with an encrypted wireless connection that changes your gears and moves your dropper post faster than it takes to blink an eye is seriously impressive.

While we’ve been running AXS drivetrains on several bikes for a while now – without fault – the component I’m going to look at here is the Reverb dropper post. Like its hydraulic relation, it’s available in most common seatpost diameters and a variety of drops from 100mm to 170mm, so you shouldn’t have a problem finding one to suit you and your bike.

Externally it’s slightly different to a regular Reverb. For one thing, the head uses a side clamp arrangement, rather one that grips the rails from above and below. This is to allow room for the electronics and battery, which clips into the back of the post just beneath the saddle. Side clamps have a bad habit of rotating under hard landings, but RockShox has added a T25 angle adjust bolt that makes it easier to dial-in your seat position as well as keeping it completely secure.Internally it gets the revisions introduced 
to the hydraulic Reverb last year, including 
reduced friction and a Vent Valve to purge 
any trapped air and get rid of the dreaded Reverb bounce. Equally good news is that service intervals have increased from 200 
to 600 hours.

Lever mounts unobtrusively on to the cockpit

The post itself is paired to an AXS control unit (which can also be configured as a shifter if you have an AXS mech). It mounts to a SRAM brake lever via a Matchmaker mount, or with a simple band-on bar clamp. This is actually quite useful, as it can sit closer to the grip if you like to run your brake levers further inboard for better leverage.

While we realise it’s not something many mountain bikers do on a regular basis, installing the RockShox Reverb AXS into a bike is a dream compared to any internally-routed dropper post. You simply insert it into your frame, tighten the seat clamp and press the buttons on both units to pair them up. It’s literally a 30-second job. Which means you can realistically buy one Reverb AXS and run it in all your bikes, providing they have the same seat tube diameter. Which starts to make the £700 asking price slightly less eye-watering. Although more on that later.

Our 150mm drop post had a 245mm insertion depth and measured 215mm from base of collar to middle of the rails at full extension. Which means it’s not as low-profile as the new hydraulic Reverb but it takes up less room in the seat tube because you don’t have 
a hose to worry about. One word of caution; because the battery is mounted vertically at the back of the seat clamp, it can run into interference problems with the back wheel on some bikes. Mostly these are long travel 29ers with short seat tubes, so it’s worth checking if your bike falls into this category.

Battery clips in neatly below the saddle

As the seatpost battery only has to open and close a hydraulic port, it uses very little energy, and a single charge is said to last around 40 hours, which tallied with our experience. Charging only takes around an hour, too, so if you go to grab your bike and find the LED light flashing red, it won’t take long to top up. Equally, the watch battery in the control unit should be good for over a year. By downloading the SRAM AXS app, you can also connect to the post and check the battery life more accurately. The battery is the same one used for SRAM’s AXS rear derailleur as well, and spare’s cost £50 (less online) and weigh around 25g, so if you’re really paranoid about running out of juice in the middle of nowhere, it’s no sweat to carry a spare.

Even compared to the regular Reverb, the RockShox Reverb AXS version responds rapidly. Like instantaneously. And the speed that the post extends is almost as fast as the Specialized Command Post. There’s a deliberate thunk as it tops out, to let you know it’s fully extended, and it’s smooth to retract when you put your weight on it. The control unit itself is large and easy to find, and no harder to micro-adjust than a cable or hydraulic version. Although it’s quite sensitive, you still need to make a concsious effort to release the hydraulic valve. With a wired remote you can sense the pressure required and almost regulate the valve opening with a partial push, and while AXS is much more of an open/shut action, we can’t remember suffering a single accidental release.