Video: Flight Attendant – RockShox’s Self-Adjusting Computer-Controlled Suspension10 min read
Oh, and the entire thing is wireless, powered by the same AXS batteries as SRAM’s electronic drivetrain.
• Intended use: 130-170mm of travel
• Auto adjusts fork and shock’s compression damping
• Manual adjust low-speed rebound, Bias
• Wireless, uses AXS batteries
• Availability: OE only (for now)
• Weight: approx +300-grams vs equivalent non-Flight Attendant system
• MSRP: TBD
As you might imagine, there’s a lot to talk about with Flight Attendant. We’ll cover the basic details and questions below, and you can check out Mike Kazimer’s full-length review for all the riding impressions.
What is it and what’s it for?
The whole idea behind Flight Attendant is simple: make your mountain bike pedal better while still prioritizing the downhills. RockShox’s approach is simple, too: add compression damping to make that happen. You know, just like those pedal-assist levers that you see on pretty much every shock on the market, only you don’t have to think about flipping a lever at all. Instead, sensors on your bike tell the fork and shock to do it automatically, which is when small motors run through small gearboxes to ramp up the low-speed compression damping. And that makes a big difference on the trail.
We suspected that SRAM was working on some sort of AXS-powered suspension system way back when their wireless drivetrain was first released in February of 2019. While I was shifting gears at that press camp in Tucson, Arizona, their development riders were on nearby trails testing prototypes. They did their best to avoid us, unfortunately for me, and SRAM did their best to dodge any questions that weren’t about their drivetrain. I found myself at SRAM’s North Vancouver office shortly after that trip and spotted the phrase ‘Flight Attendant’ written in massive red letters on their whiteboard, but that was back then we thought it was a relatively simple wireless lockout with maybe some sort of integration with the drivetrain or dropper post, and probably aimed at the short-travel Lycra crowd.
However, Flight Attendant appears to be far more useful than a lockout switch, and it’s been designed with enduro and trail bikes in mind.
What are the Flight Attendant components, and how does it work?
Flight Attendant consists of three important components, but I should mention straight away that they’re mounted to an essentially normal fork and shock. The Pike, Lyrik, and Zeb Ultimate, as well as the Super Deluxe Ultimate shock, all have normal internals, normal damping circuits, and aside from the funny-looking LED-equipped growths hanging off them, are both standard items. Does that mean you’ll eventually be able to convert your current RockShox boingers to use Flight Attendant? Maybe way down the road, but it’s not happening anytime soon.
The three main Flight Attendant components are the Control Module on the fork (pictured above), the Motor Module on the shock, and a pedal sensor that slips into your crank spindle. You need all three to use the system, which means that you can’t run just a Flight Attendant fork or just the shock – they function only as a team.
The Control Module on the fork is the brain of the entire system, and it’s what tells both the fork and the shock to firm up or go soft. There’s an accelerometer and gyro hidden in this little unit (as well as in the shock) and, along with the pedal sensor, it’s how it knows what your bike is doing so it can tell the suspension what to do. The sensors know if you’re pedaling or coasting, if you’re upright or leaning over mid-turn, if the bike is angled up, down, on flat ground, or if you’re in the air, and adjusts the compression damping accordingly. The pedal sensor is especially important to the system, I was told, as it’s what allows Flight Attendant to predict what’s happening rather than just reacting, but it’ll only fit into DUB spindles as of right now.
Picture this: you’re descending on your enduro bike and everything is normal, with the suspension wide open and able to do its thing. All of a sudden, you’re faced with a short, steep climb that’s trying to ruin your fun. As soon as your bike’s sensors know that it’s pointing up a hill and you’re on the gas, the Control Module sends an order to both the fork and shock to stiffen up so it doesn’t feel like you’re trying to double bounce a stationary bike on a trampoline. At that moment, the little motors spin at roughly a million RPM, which is then put through tiny gearboxes (just like on an AXS derailleur) to simply turn the compression rod to firm up your bike. Notably, you can adjust how often that happens via the important Bias Adjust that we’ll get to in a bit.
When the bike senses that you’re back to the fun part of the ride, it opens the fork and shock’s compression back up to where you want it. It’s probably important to mention that your rebound damping will always be unaffected – it’s a manual adjustment that doesn’t change because that’d be really scary.
Flight Attendant forks and shocks are essentially normal units but with the Control and Motor Modules attached to them. That means they can be worked on as per usual, be it some quick love in the garage or deeper maintenance.
But how does it know to do all that? ”Flight Attendant’s algorithm is highly sophisticated and born from thousands of hours of rider input and data analysis,” RockShox says, and it’s all hidden in the Control Module’s brain on top of the fork. There’s also a fundamental difference between this and Fox’s older Live Valve system (aside from this being wireless), with Fox favoring pedaling efficiency while, according to RockShox, ”Flight Attendant’s highest priority is adjusting the system to the open position when bumps or disturbances are detected and will adjust the system to be more efficient when it senses the rider pedaling.”
Is it adjustable?
Flight Attendant-equipped forks and shocks are both more and less adjustable thanks to them losing the external high-speed compression dial (it’s now non-adjustable) but gaining something called Bias Adjust that’s a super integral part of how the system performs.
First, your normal low-speed rebound adjustment dials are still where you expect them to be, at the bottom of the fork leg and top of the shock. Nothing has changed there. But what you won’t find is a dial for low-speed compression; that’s adjusted via buttons on the top of the Control Module that controls both the fork and shock. Yup, you now adjust the shock’s compression damping at the fork by toggling between the two. And because the future is apparently now, you can also make the same adjustments via the AXS app, if you’re into that kinda thing. Different colored LEDs on the module also tell you what you’re changing and by how much.
Bias Adjust is the new tuning feature, and it’s also changed either on the Control Module or in the AXS app.
RockShox has a long-winded explanation about Bias Adjust, but the gist of it is this: more Bias means that your bike will feel firmer and more efficient more often, while less Bias means it’ll stay open and pedal like a gooey enduro bike more often. An obvious example of where this might be useful would be a rider who’s taking their enduro bike to a relatively smooth, flowy network of trails. They might want to add a click or two (of five in total) of Bias Adjustment to bring more life and momentum to their bike. A rider who spends more time on rooty, rough, complicated trails, or if traction is low, might want less Bias so their bike is more active, more often.
RockShox says that running it in the middle setting provides, “an effective balance of all three suspension positions,” and that there’s, ”no right or wrong, Bias Adjust is all about choice and fine-tuning the feel of the system to better match your ride style.” Adjusting it takes only a few seconds by pressing a button on the Control Module.
Depending on your Bias setting, those three modes – Open, Pedal, and Lock – are constantly being cycled through while you ride in Auto Mode, but they can also be chosen manually if you decide to not let the robots do the thinking for you. That gives you the ability to choose which mode you want by pressing a button on the fork’s Control Module or your chosen paddle on your left-side AXS shifter. You can always open, firm up, or lockout your suspension at the push of a button if you’d rather decide than let the computer do it. There’s also an Override Mode that, at the push of a button on your shifter, can revert to a preferred suspension setting – pretty neat.
Speaking of settings, Kazimer’s review of Flight Attendant also shows you how to pair and set the system up from scratch. You only need to do this five-minute process once, unless you make notable geometry or travel changes to your bike.
Really, more batteries and apps?
Hey, at least it’s wireless. Flight Attendant requires two of the same AXS batteries used for the derailleur, with one attached to the Control Module on the fork and the other powering the Motor Module on the shock. RockShox says to expect 20 to 30 hours of battery life for the former, and 30 to 40 for the latter. The pedal sensor (that only fits DUB spindles for now, but that might change) is powered by a AAA lithium battery that should last for around 200 hours, so you won’t need to think about that one until it dies in the middle of nowhere.
Don’t forget that if that happens the suspension reverts to full-open mode rather than some terrible firm setting.
If you’re like me and the thought of using an app to do anything other than find the closest Tim Hortons makes you groan, the good news is that you definitely don’t need to. All of the setup and adjustments can be done without using your phone, but the AXS app does let you customize controls, get a better idea of the remaining battery life, and do any firmware updates. You can also tweak compression and Bias for the fork and shock via the app, which is a neat and maybe-sometimes handy trick, but I suspect most would rather leave their phones alone.
Where can you find this stuff? How much will it cost?
Not for sale in your bike shop anytime soon, that’s for sure. You see how the Control Module hangs off the back of the fork, and how much larger the shock is thanks to the Motor Module? Because more downtube and shock clearance is required, there are bikes that Flight Attendant won’t fit. Factor in the already long lead times and you can see why RockShox couldn’t give me a date for aftermarket sales. I don’t have any aftermarket costs for you at this point, either, but you know how an AXS derailleur costs a lot more than a normal one? Yeah, think along those lines and you probably won’t be too shocked when you see the price tag.
The only brands currently selling Flight Attendant-equipped bikes are Specialized, Trek, Canyon, and YT, but that’ll change down the road.
For this year, you’ll only find Flight Attendant on a grand total of six bikes spread across four brands – Trek, Specialized, Canyon, and YT – with travel ranging from 130mm up to 170mm. It’s probably safe to assume those will be expensive bikes… The Specialized S-Works Enduro that Kazimer tested Flight Attendant on will retail for $12,500 USD, or $2,000 more than the version without smart suspension, so that gives you an idea of what to expect.
What do I think?
I hate computers, and my level of technical expertise when it comes to this kinda stuff can be summed up with, ”Unplug the router, wait ten seconds, then plug it back in.” Sometimes, I think it’s the wifi that’s making me itchy. Furthermore, it’s almost a certainty that anything battery-powered I touch stops working soon after, usually in the acrid smoke of an electrical fire. So yeah, I’m naturally wary of anything with a circuit board for valid reasons. I’m a fan of the AXS drivetrain, sure, but this is different, isn’t it? This is doing something on its own…
But it also was completely invisible during the single, 3,000-foot descent that I used it on. The Flight Attendant-equipped Enduro felt as capable and competent as our long-term Enduro test bike that we’ve all put countless hours on. That is until I had to pedal it up anything, which is when it acted like it had about 140mm-ish of firm suspension travel. More importantly (and impressively) was how it transitions seamlessly between the different modes on rolling sections of trail, adding some pep to the usually soft-feeling Enduro as needed.
If you’re looking for a proper review and more feedback, Mike Kazimer has a month of riding on the same bike and you can read his thoughts on the homepage right now. As for me, I’m impressed and have yet to unplug the router.