SRAM’s all-new wireless Reverb AXS dropper post comes with a slight weight penalty over the mechanical equivalent and certainly isn’t cheap at £700 / $800 / €800, but the ease of setup and, so far, the flawless function has absolutely won me over.
You may well have seen certain bikes at various races or events during 2018 sporting the new Reverb AXS post, but that said, sightings were rare at best and nowhere near as common as that of the new Eagle AXS drivetrain.
As it turns out, SRAM has actually been cooking up this wireless gem since as far back as 2016 and, as of right now, it’s officially available to the public.
The Reverb AXS started development back in 2016, and unlike the Eagle AXS drivetrain, it’s not been seen out in the wild an awful lot. That’s all about to change thoughMargus Riga/SRAM
I flew to Tucson, Arizona for a few days in a bid to get to know the new Reverb AXS a little better.
Wireless Reverb AXS dropper post details
The big selling point here, for me at least, is the lack of hydraulic hose. While RockShox isn’t the first to do away with cables and create a wireless dropper post, those that have brought products to market haven’t exactly delivered the most polished products. Most importantly, no one has trumped the mechanical equivalent yet.
Sure, there’s a variety of designs out there that have their quirks and foibles, but we’re at a point where cable or hydraulic actuated posts are really quite good.
Via the app you can re-allocate different functions to different buttons
So why go to all this effort? According to RockShox, the plan was to ditch all hoses and the routing that goes with it but without impacting on the performance. It wanted to “create a reliable wireless-electronic dropper post and controller that actuates with drastically less effort and zero distraction.”
The remote and post talk to one another using SRAM’s encrypted wireless network, which it claims is totally secure. Once installed, which with no cables or hoses to worry about takes a matter of seconds, it’s simply a case of pairing the two components together. This can be done by holding down the two pairing buttons simultaneously. It’s as easy as that.
The system also uses Bluetooth to enable you to connect to the new AXS app where you’re able to customise your controls (that is, should you have splashed the cash on the Eagle AXS drivetrain too).
Via the app you can re-allocate different functions to different buttons, so you could potentially have your Reverb remote set to do downshifts, with one of the three buttons on the Eagle AXS shifter controlling your dropper post, check battery life and keep an eye on the mileage your putting in on the trail.
In order to sync your phone with the Reverb AXS remote and post, you will need the components right there in front of you, because when syncing with the app, you do need to physically press the AXS buttons on each component, making the whole system that bit harder to tamper with.
While you don’t really need the app to use the new post, if you do choose to use it, it’s a doddle to get to grips with and easy to understand.
Reverb AXS dropper post remote lever
This entirely new remote was designed by SRAM’s drivetrain team (it was created in tandem with the new wireless Eagle AXS drivetrain) and features a paddle/button to actuate the post. It weighs just 55gMargus Riga/SRAM
The new wireless remote is quite the leap from the lever style remote RockShox introduced in 2017, and, in feel and function, a massive jump over the original push button remote that’s still available today.
That’s mainly down to the neat little paddle used to actuate the post. There’s very little paddle travel when you push it, it’s more like hitting a button, and the actuation feels beautifully light.
If you’ve seen the Eagle AXS shifter, then you’ll have spotted a number of similarities. That’s because it was the same design team that created this little number.
Inside sits a small CR2032 battery, which RockShox claims will last for a good couple of years’ use.
As I’ve already mentioned, the new remote can be customised in the AXS.
Reverb AXS dropper post saddle clamp and head design
The real business end of the operation is the new post itself. RockShox has had to create a totally new head to accommodate the motor and battery. This means the revised head now uses a single bolt saddle clamp but includes a tilt adjust bolt to add security and make set up that bit easier.
The revised head design meant RockShox had to use a single bolt saddle clamp to secure the seat. It has incorporated an additional tilt bolt though which not only helps with saddle adjustment, but also securityMargus Riga/SRAM
Single bolt saddle clamps aren’t something I’m a huge fan of because it’s hard to get them to tighten enough to avoid them moving under load, but during my brief stint using the post, I had no issues with the saddle slipping.
Naturally, it’s the battery and motor that gets most of the limelight. The battery is identical to that used on the Eagle AXS drivetrain and weighs just 25g. The battery from the AXS post and Eagle AXS derailleur can be switched should one run out of juice.
SRAM claims the battery will get around 40 hours of ride time and will take about an hour to charge back to full capacity. To check battery life, it’s simply a case of pressing the AXS button on the post and watching the small LED. If it’s green, the battery is fully charge, or close enough. A red light means it’s half full or thereabouts, while a flashing red light means get it plugged in to charge.
When not in use, the post ‘sleeps’ in a bid to help conserve battery life. Moving the bike or hitting the remote ‘wakes’ it up ready for action.
This means it’s wise to remove your battery when travelling with your bike in the car because, thanks to the accelerometer inside the post, your post will remain on high alert throughout.
Another big plus for those that have suffered that oh so annoying squish in the past is the introduction of the Vent Valve
Obviously, if you’re not going far, this will have a negligible effect on battery life, but if you’re trekking down to the Alps it’s sure to take a toll. As the battery is held in place with a single clip, removal is easy. If the battery does die, you can’t adjust it manually.
The motor used to actuate the post — it moves a small pin which opens and closes a valve — is bigger than RockShox may have actually needed. The big worry here was how fast the post was to react, which is why RockShox went for one with a little more oomph.
It’s at this point that it’s probably worth pointing out that, even with an integrated motor, this post doesn’t drop itself. The rider still needs to weight the saddle while pressing the remote in order for the post to drop, just like a cable actuated equivalent. RockShox did consider this level of functionality but the extra bulk and cost meant that the idea was soon shelved.
And that’s why it’s not just the head that’s had a makeover. The guts of the post have had an overhaul too and now feature a new, lower friction internal floating piston to help boost reaction time and reduce the amount of force needed to drop the saddle.
There’s also a lower friction oil in use and the new RockShox Dynamic grease, which replaces the use of slick honey, as it’s said to degrade more slowly. The big plus here is that these improvements have helped boost service intervals from 200 hours to a massive 600 hours, which is seriously impressive.
Another big plus for those that have suffered that oh so annoying squish in the past — something that’s plagued Reverb’s for a long while — is the introduction of the Vent Valve. The squish comes from air mixing with oil. The Vent Valve allows you to purge the air out from where it’s not supposed to be and back into the air chamber.
It’s easy to do too. You’ll need to remove the post and depress the valve at the base of the post and compress the post.
Unlike the mechanical version of the Reverb, return speed can’t be altered on the new AXS offering though, by default it feels pretty rapid in use.
I know I’ve touched on this already, but the lack of cables or hose means the new Reverb AXS removes all of the hassle when it comes to fitting a post. While others can claim this too, the Reverb trumps them in terms of performance.
It also means, should you have multiple bikes that take the same diameter seatpost, swapping between them is easy. Another big plus is decluttering your controls and preventing any annoying cable rattle.
Reverb AXS dropper post travel lengths and post diameters
RockShox had to redesign the head of the post entirely to incorporate the 25g battery and small motor. Despite it’s bulky looks, stack heights remain the same when compared to the conventional mechanical post, and weights only increase slightlyMargus Riga/SRAM
While there’s no getting away from the fact that the Reverb AXS post boasts what looks to be a far chunkier head than it’s mechanical equivalent, you’ll be pleased to hear that overall stack heights are identical.
Travel options are also the same, as is the ability to stop it at any point in that travel. RockShox offers the post in 30.9mm, 31.6mm and 34.9mm post diameters and 100mm, 125mm, 150mm and 170mm drop options.
How waterproof is the Reverb AXS dropper post?
Naturally, this post is going to get caked in mud and a decent soaking for at least half the year. This is why the new Reverb has been built to an IPX7 waterproof rating.
As of yet, RockShox claims it’s had no issues with water ingress, though of course once we get our grubby little hands on one we’ll be able to put it through a dirty British winter and really give it a hard time.
Reverb AXS dropper post weights and prices
Well, that sounds a little dramatic, but as you’d expect, adding all this tech does mean the new post is a touch heavier, but not a lot. According to RockShox, it claims that the mechanical 30.9mm, 100mm drop Reverb weighs 560g, while the Reverb AXS weighed in the same spec weighs 573g.
The 170mm post, still in a 30.9mm diameter, weighs a claimed 647g, which certainly isn’t bad, but is still heavier than Magura’s wireless post, the Vyron, though the Reverb AXS trumps this on performance.
Another potential sticking point will inevitably be the price. At £700 / $800 / €800 it’s certainly not cheap.
Reverb AXS dropper post ride impressions
Reverb AXS dropper post ride impressions
With all the detail out of the way, it’s the (initial) ride experience that can really make or break a product. I must say, I walked away from this trip genuinely excited about the new Reverb.
There’s no denying it costs a load of money and mechanical posts work seriously well, but the new Reverb is incredibly impressive on the trail. The light actuation and easy to reach button requires just a quick tap to rapidly raise your seat. There’s no annoying delay and, in practice, it feels as fast if not faster than the best posts of the current crop.
As the Tucson trails feature a number of technical climbs and awkward mellow, but super rocky descents, I found myself constantly micro-adjusting the post — hats off to SRAM, which picked a good place to give the post a decent working over.
With the ease of use and how convenient the remote is to press, I’d say I used the post more than I would normally, especially on awkward climbs that needed the saddle dropped or raised just a bit.
Not having to use the extra effort required to fully depress a lever meant I could hit the remote with my knuckle and adjust with ease. This sounds like I’m being really lazy here, but when you’re gasping for breath trying to clean a climb, that effort can sometimes be hard to muster.
Current cross-country World Champ Nino Schurter has been a fan of the wireless AXS system since he was first shown prototypes and raced on the drivetrain during the 2018 seasonMargus Riga/SRAM
While its performance is impressive on the trail, I’m becoming more of a wireless convert than I thought I would initially. As I’m somewhat of a caveman when it comes to using electronics on my bike, I can’t say I was overly excited about this at first but being able to ditch cables and the ease of set up is a big plus for me. I’m also a big fan of the Vent Valve and really hope it makes it onto the mechanical posts in the future.
Of course, my short amount of time in Arizona is no real test of the post, just an initial impression. When our test sample lands here I’ll be able to give you a far more in-depth review after logging months of ride time aboard it, so please stay tuned for that in the not too distant future.
Rob is a riding encyclopaedia of bikes and kit. He spends a lot of time travelling the world for the latest product launches and organising how and where Bikeradar's and MBUK's gear gets tested. A super-stylish rider, and indeed beard groomer, Rob has no fears when it comes to hitting the trails with the industry’s best.