SRAM FLIGHT ATTENDANT REVIEW – FIRST CLASS ELECTRONIC SUSPENSION OR TURBULENT RIDE?
It's great when it works.
Please fasten your seat belts and secure all baggage underneath your seat or in the overhead compartments. Your tray table should be in the upright and locked position. The RockShox Flight Attendant system is on board and ready to serve up all your proper suspension setting needs for this trail. Today’s service will be delivered to your suspension components as quickly as the data in your Bluetooth’s stream, and your suspension will be custom-tuned for the conditions you will encounter. Please, sit back, relax, and enjoy the ride.
SRAM’s new Flight Attendant system is a suite of sensors that reads rider and terrain inputs to anticipate the perfect suspension settings and adjust them automatically. Flight Attendant is an extension of SRAM’s AXS system that uses Bluetooth technology to allow components to communicate with each other. It makes decisions about which mode you should be in, using a collection of carefully placed sensors, and then adjusts quickly to stiffen or soften the suspension. At any time, the rider can take control, but it’s not necessary. It’s a top-to-bottom suspension system designed to make decisions for you and improve your ride. It takes the guesswork out of choosing the right setting and makes your bike easier to ride.
How it works
Sensors on board your fork, rear shock, and crankset work in unison to detect bumps, the bike’s pitch and pedal strokes. Flight Attendant’s algorithm then uses this information to choose the correct mode and to make the necessary adjustments before you need them. Flight Attendant works by controlling the damper (i.e., the compression and rebound damping circuits in your fork and shock). It does not affect the suspension by adjusting air pressure or volume. Those adjustments are made on the air spring side of the fork, just as on SRAM’s conventional models. Automatic adjustments are made internally as you ride, and the system algorithm guidelines can be set up to suit your terrain and riding style via the Flight Control app. Flight Attendant only works as a complete system, which consists of the fork and shock controllers, the crank sensor, the AXS dropper post, and the left SRAM shift lever. Each of these must be on the bike and ready to go or the app won’t allow you to set anything up.
The Flight Control app includes a step-by-step setup tutorial that takes about five minutes to go through. You will still need to set sag for the fork and shock as you would with typical suspension. Once you have that set, the app will have you sit on the bike and tilt it to the side to gather the baseline info the algorithm needs. Once this initial setup is done, adjustments can also be made with the buttons on the units.
The Three Modes
When the bike detects a downward pitch, or the instant your tires hit a bump, the open position allows the suspension to activate and use the full amount of travel. This is the plushest mode.
This is meant to be the sweet spot for efficiency on mixed terrain. The suspension feels firmer but retains enough movement to improve traction on loose terrain.
The firmest suspension setting maximizes pedaling efficiency and keeps suspension movement to a minimum. It is best for sustained climbs and smooth surfaces.
On the Trail
The instant you touch a Flight Attendant bike, you’re greeted with a flash of friendly green lights and robot noises. That’s the sign that everything is working. If you’ve already done the setup tutorial and are happy with your settings from the last ride, there’s no need to reach for the app. If you throw a leg over the bike and begin to pedal, the sensor in the crank spindle will notice and throw you right into the Pedal mode.
The system will keep you in the firm, almost-no-travel mode until you either head downhill or hit some obstacles.
If you’re pedaling through rocks, for example, the algorithm will choose the Pedal mode for you. The firmness of this mode can be fine-tuned using the “pedal bias” feature in the app, which essentially allows you to choose your mid-setting low-speed compression adjustment to feel firmer or softer.
The instant your front wheel hits a sizable bump or points down a chute, the shock and fork soften to absorb obstacles in the Open mode. This mode is the way the bike would ride with regular suspension if you never flipped the pedal switch. The suspension is active and uses full travel to improve grip and control.
In both the Pedal and Open modes, the system will continue analyzing inputs from the sensors to determine when the trail gets smooth and then switch you back to the most efficient mode. That’s really what’s at the core of the Flight Attendant system—it finds the most efficient mode and switches you to it as quickly as possible.
It’s important to know that the Flight Attendant system doesn’t work with magic internals. It doesn’t have a built-in compressor to adjust air pressure on the fly. In fact, it doesn’t even affect anything in the air spring side of the fork and basically works like a little robot that adjusts the compression damper circuit according to the data it receives from the sensors. It also won’t take all the guesswork out of setup. It requires quality inputs from the app and setup to function properly.
The Flight Attendant system uses two rechargable SRAM AXS batteries: one in the shock and one in the fork. There is also a AAA battery in the sensor inside the crank spindle. The batteries in the fork and shock lasted for roughly two to three long rides before we felt anxiety about them being at less than 50 percent and charged them. The crank battery lasted the duration of our test and needs to be changed less often. When paired with the rest of an AXS system, like our YT test bike tested on page 24, that makes for a total of six batteries that must be kept charged.
Firmware Updates and Warranty
The fork control unit refused to turn back on after we removed the battery for charging. A call to SRAM had us performing a firmware update that seemed to solve our issue for another few rides; however, when we removed the battery the next time for charging, we replaced it and the unit refused to turn on again. After a second call to SRAM, they sent us a new warranty unit with no explanation of what may have happened.
We rode the bike in dry conditions, but the failure happened both times after washing and drying our bike (with a bucket of water, not a pressure washer). We speculated the issue could have been water ingress, although we have no evidence beyond the timing of the failures. We never told them it was a magazine bike to get a favor from the warranty department, and we were satisfied that SRAM replaced the defective unit with no questions asked.
SRAM shows us a glimpse of the future with Flight Attendant. While suspension technology has improved by leaps and bounds in the past 10 years, many riders leave performance on the table by not knowing when or how often to use their suspension adjustments and switches. Many more simply choose to keep it simple and never think about flipping a switch. In either case, Flight Attendant offers a huge increase in performance, simply by taking the guesswork out of the equation. It ensures you will use your suspension controls, even though you’re not specifically thinking about which lever to flip and when. Flight Attendant makes your bike easier to ride. It makes adjustments faster than any person could, simple as that. The setup procedure is impressively easy, and the concept is deceptively simple. It basically uses an algorithm to do some of the thinking for you, so you can spend more of your mental bandwidth conquering trail obstacles.
While Flight Attendant makes the on-bike experience easier, there’s no doubt that it is extra work to ensure the batteries are charged and working. When it was working, it undoubtedly made the bike easier to ride and allowed us to extract more performance from the damper system. When it didn’t work, we felt the pain of canceled ride plans and downtime waiting for our warranty parts to return; however, the benefits of riding with Flight Attendant were enough for us to start looking for more frequent-flier miles aboard bikes equipped with this system. At this point, Flight Attendant is still only available on select RockShox-equipped bicycles and with upgrade kits for select bicycles.