RockShox Reverb AXS B1
Lengths Available: 100 mm, 125 mm, 150 mm, 175 mm, 200 mm, 225 mm, and 250 mm
Diameters Available: 30.9 mm, 31.6 mm, 34.9 mm
Blister’s Measured Weights:
- Reverb AXS post: 740 g (30.9 x 225 mm, with battery)
- AXS Pod Controller: 58 g (with Rocker paddle, discrete clamp, and battery)
MSRP:
- Seatpost: $549 USD
- AXS Pod Controller: $150 USD
Intro
The RockShox Reverb AXS opened the floodgates to electronics on mountain bikes when it was released back in 2019 alongside Eagle AXS. It addressed some of the reliability issues of prior Reverb designs, too, but as droppers started getting more and more drop, the Reverb AXS started to feel a bit outdated with its maximum 170 mm of travel.
SRAM has been busy with new releases this year, and the updated Reverb AXS B1 is officially here, too. It addresses the travel limitations of the old one by going as high as 250 mm of drop, but it also brings a novel internal design with an air-over-air layout rather than a more conventional oil-filled cartridge. In addition to simplified internals, the design brings something that SRAM calls ActiveRide — as the post moves into its travel, the seatpost can move under the rider’s weight to absorb bumps.
It’s a big update, so let’s unpack the changes below. BLISTER+ members and folks with our Digital Access Pass can check out our initial ride impressions in our Flash Review, too.
Design
Starting with the general layout of the new Reverb AXS B1, it’s immediately clear that a lot has changed in the new one. Compared to the original, the new Reverb AXS adopts a more traditional two-bolt seat clamp assembly, moving the electronics module and battery to just below the seal head (much like Fox’s Transfer Neo). The simpler seat clamp accommodates both round and oval rails and should do away with the slipping issues that could come up on the older style seat clamp, too. RockShox has also vastly expanded the range of travel options available, ranging from 100 mm to 250 mm in 25 mm increments, and the new Reverb AXS is available in 30.9 mm, 31.6 mm, and 34.9 mm diameters.
Unsurprisingly, the battery is the same AXS battery used across all of SRAM’s AXS-powered components. The electronics module now sits at the bottom of the post rather than in the post head, and RockShox says that the new battery placement allows for a simpler design that doesn’t require special tools for disassembly. The battery mount takes up a good bit of real estate around the seal head, increasing stack height over a mechanical post. RockShox’s press release doesn’t state the exact number, but I measured it at about 62 mm on our 30.9 x 225 mm sample — just a few millimeters shorter than the 65 mm stack height of the original Reverb AXS (measured from bottom of the collar to center of seat rails, with post lowered). That means it’s still a good bit taller than the 47 mm stack height of the Fox Transfer Neo, and more than twice the stack height of the OneUp V3.
There are some very big changes inside of the Reverb AXS, too. Rather than your typical oil-filled cartridge with an air-backed IFP, the Reverb AXS uses an entirely air-based cartridge design. The design’s goal is to minimize the number of parts and increase durability — and as you can see in the graphic below, the number of internal parts is quite small.
Part of what allows a more conventional dropper post cartridge to stay firm at a given height is the use of oil, which is very good at resisting compression but loses that ability once air makes its way into the cartridge. By using an air-only spring design, RockShox doesn’t have to worry about keeping air and oil separate within a cartridge, but it does mean that the seatpost doesn’t remain totally rigid once lowered from topout. In this case, though, RockShox doesn’t seem to think that extra bit of give is a bad thing — and they’re calling it ActiveRide.
Some folks may recall the suspension seatposts that were semi-common in the late 90s and early 2000s, and some readers may have noticed their slight resurgence amongst the Gravel community. ActiveRide basically brings a similar suspension element to the new Reverb AXS. When the seatpost is at topout, there’s virtually no negative air spring volume in play, and the post is rigid. As the post is lowered, the negative chamber volume increases, allowing the post to compress slightly under the rider’s weight. RockShox touts ActiveRide as helping with comfort while seated in technical terrain, especially on steep, punchy climbs.
RockShox also claims that the simpler air-only cartridge simplifies service. There are relatively few parts and no oil-filled cartridges to bleed — RockShox says a basic service is advised every 300 hours of riding (or once a year), and RockShox sells 600-hour (or two-year) complete service kits. While the service doesn’t require true specialty tools for disassembly, it does require some vise blocks and a high-pressure shock pump. The 30.9 mm and 31.6 mm diameter posts have a minimum air pressure of 400 psi and a maximum of 600 psi, while the larger diameter 34.9 mm model drops to a 225 psi minimum and 335 psi max. All posts ship at their maximum recommended pressure, but adjusting pressures will require a high-pressure pump, sold separately.
Some Questions / Things We’re Curious About
(1) RockShox went back to the drawing board, and the new Reverb AXS sees big changes throughout the design. How does it measure up to other droppers on the market, both electronic and mechanical?
(2) How noticeable is the ActiveRide technology’s movement while riding, and does it bring the comfort and compliance benefits that RockShox claims? Are there drawbacks?
(3) Should we expect to see a cable-actuated version of the new Reverb AXS B1, or will it be an electronic-only affair?
Bottom Line (For Now)
Aside from still using the AXS battery, the new Reverb AXS B1 is a ground-up overhaul — and one we’re happy to see finally hitting the market. The major highlight from our wish list is the vastly expanded range of travel options, but RockShox’s new air-on-air spring design is a truly novel addition. We’ll have to see whether its durability claims prove out, but our big question is how the ActiveRide technology will feel on the trail.
BLISTER+ members and those who purchase our Digital Access Pass can check out our initial ride impressions in our Flash Review below, and we’ll be sure to report back on our findings in a Full Review in a few months.
Flash Review: Our Initial On-Trail Impressions
BLISTER+ members and those who purchase our Digital Access Pass can check out the Flash Review below to read our initial on-trail impressions. Get our Digital Access Pass to view all our Flash Reviews and Deep Dives, or become a BLISTER+ member today to get access to that and a LOT more, including the best worldwide Outdoor Injury Insurance, exclusive deals and discounts on skis, personalized gear recommendations from us, and much more.
Flash Review: RockShox Reverb AXS B1
The new Reverb AXS B1 dropper from RockShox represents a ground-up redesign of the old one. Does it deliver a better on-trail experience? We’ve been riding the new one, and have some initial thoughts to share.
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