Just biking and not having to concentrate on anything else. A simple wish. However, as comfort and efficiency are not always in harmony on a fully, the mountain bike suspension plays a key role. Depending on the riding situation and surface conditions, the suspension fork and shock absorber must ideally adapt. Maximum sensitivity when it comes to smoothing out root carpets, but also firm and efficient when pedalling on gravel or roads and anything in between on undulating terrain. If you always wanted the right setup, you always had to use the platform lever - if available - on the fork and shock. Kind of awkward.
The Accell Group thought that there must be an easier way to do this back in 2012, when it teamed up with Trelock as a development partner to bring electronics to the chassis. The E:i-Shock system was used by Haibike, Ghost and Lapierre and, thanks to sensors in the bottom bracket, headset and fork, was intended to automatically set the right mode on the shock. This was only partially successful due to the low speed of the sensors and servomotor, which is why the system disappeared again after a few years. With Live Valve ignited suspension giant Fox Thanks to the advanced sensor technology and the much faster reaction speed of the control unit and valve control in the fork and shock, Live-Valve was able to fully convince in practice. However, the hefty surcharge of around € 2000, the additional cabling and special mounts on the frame made the system an absolute niche product without any significant distribution.
Flight Attendant: Wireless and part of the AXS system
With the wireless AXS technology provided Sram/Rockshox In recent years, electronics have made smart inroads into mountain biking. Thanks to their simple installation and reliable function, dropper posts and, above all, AXS drivetrains are becoming increasingly popular. So it was only a matter of time before Rockshox followed suit with an electronic suspension system, which of course works wirelessly. After seven years of development, Rockshox fulfils exactly these expectations with Flight Attendant. Unlike Fox's Live Valve suspension, the four individual electronic components in the fork, shock, bottom bracket and the optional controller on the handlebars communicate with each other wirelessly via the AXS network. Each component therefore requires its own power source.
You can download the detailed test story on the Rockshox Flight Attendant automatic e-suspension from BIKE 12/2021 as a PDF below the article.
As all Flight Attendant components are installed directly in/on the fork and shock and the pedalling sensor is compatible with most DUB crankshafts, integration on the bike is extremely simple. As long as the frame can accommodate a shock with a reservoir, all hurdles are overcome. Like Fox, Rockshox relies on the interaction of acceleration and position sensors for its new suspension, which recognise the terrain and riding situation and automatically select the correct suspension setup accordingly. However, thanks to the additional pedalling sensor in Flight Attendant, the system also knows whether the rider is pedalling or rolling and can prepare itself accordingly. The logic also differs from Fox's two-stage system, which only switches between opening and closing the suspension. While the Live Valve only opens the locked suspension at lightning speed when required, Flight Attendant always works with the suspension open and switches to a platform or lockout mode depending on the situation.
Only on complete bikes from YT, Canyon, Specialised and Trek
As the shock (Super Deluxe) of Flight Attendant also has to be adjusted to the respective rear triangle of a full-suspension bike, the entire system will initially only be available on selected complete bikes. Canyon, YT, Specialized and Trek are the brands that exclusively offer bikes with Flight Attendant. For 7999 euros each, these are Canyon Neuron and the Spectral the most affordable bikes on the road to the future. The Jeffsy and the Capra from YT are just above this at 8999 euros. The two enduro bikes from Specialized and Trek are likely to be considerably more expensive, as the two current top models (Enduro S-Works and Slash 9.9) are already priced at € 13,500 and € 11,999 respectively. You can expect a surcharge of at least 2000 euros. In addition to the Super Deluxe rear shock, there are three fork models to choose from. Rockshox offers Flight Attendant in the Pike, Lyrik and Zeb platforms, covering the spring travel range from 120 to 190 millimetres.
First test: How the Rockshox Flight Attendant suspension rides
When the batteries are inserted, the system wakes up to the clearly audible whirring of the servomotors. Before hitting the trails for the very first time, the system undergoes a brief, one-off calibration. Once the fork and shock know where they are in relation to each other - which means uphill, downhill and lean angle - you're ready to go. The green LED on the fork signals automatic mode. I sprint uphill on gravel, the suspension tightens up and there is no pumping. At the top, the first root puts the suspension on alert. The servomotors open the forks and dampers immediately and the obstacles are swallowed up. As soon as the trail becomes tamer again, the system switches to platform mode. First at the rear, then at the front. Depending on the bias setting (sensitivity), the platform or the lockout is used in preference. The suspension does what it is supposed to do and does so unobtrusively, without hooks or jerks. In rough terrain, it is noticeable that there is much less bottoming out in the travel. The system keeps me higher in the suspension travel without having to sacrifice comfort. Active riders who like to use the terrain for pushing get more support. However, even though the signals are processed in just five milliseconds, the actuators in the damping units work more slowly than the solenoid valves in the Fox system, for example. If you hit an obstacle while cranking with the suspension locked out, the servomotor opens instantly, but you will feel the obstacle a little more, at least on the fork, than if you hit it with the fork open. However, this is perfectly acceptable as the lockout on the fork is less tight than on the shock.
Test summary of the Flight Attendant by BIKE test manager Peter Nilges
In contrast to electronic shifting, where in principle only a mechanical shift command is replaced by a radio signal, the Flight Attendant suspension offers real added value for the driver. After eight weeks of use, one thing is clear: you could never adjust your suspension manually as quickly, reliably and unobtrusively as in automatic mode. The bottom line is that you are more efficient on the road and can concentrate fully on biking. Batteries on all individual components and the initially very high price are the downside of the successful system.
Which batteries are installed and how long do they last?
While the button cell battery in the controller and the AAA battery in the pedalling sensor should last 200 hours, the fork and shock have the identical battery known from the AXS shifter and dropper post. Rockshox claims 30-40 hours of riding time for the shock and 20-30 hours for the fork.
The AXS app: All settings can also be made via the AXS app can be made. Depending on the sensitivity of the system (bias), the pedal or lock mode is used more frequently. In Open mode, the low-speed compression on the fork and shock can also be adjusted tenfold. The compression setting as well as the pedal and lock function are each operated by a servomotor in the fork and damper. In open mode, a needle valve regulates the oil flow. In pedal and lock mode, the needle moves to a different valve segment.
Innovations, development and future of the Rockshox Flight Attendant suspension
BIKE: Who is Flight Attendant aimed at and what should the new suspension do?
Jon Cancellier, Rockshox Product Manager: "Flight Attendant is interesting for every mountain biker who wants to improve their efficiency. Instead of manually adjusting the suspension to the riding situation every time, we take this decision off the rider's hands and make it easier for them.
What were the biggest challenges during development and how long did it take overall?
One of the biggest challenges is that we are not an electronics manufacturer. We couldn't rely on existing actuators, interfaces and gearboxes, but wanted to realise all our ideas ourselves from scratch. The development therefore took seven years, even though we had already gained a lot of experience with the eTap wireless road bike shifter and the Quarq power meters.
How did the development process go, given that you were involved in the E:i-Shock electronic chassis back in 2012?
At the time, we were not directly involved in the development, but only provided the Monarch damper for the system developed by Trelock. That's why we entered uncharted territory seven years ago. We initially started with two suspension modes (open and lockout), but quickly realised that a third platform level was a really good addition. The pedalling sensor, which records the input from the rider, also makes perfect sense and provides valuable information for selecting the appropriate mode. With every development, we have to anticipate what people want and, because we are embedded in the AXS world, we are also able to add new functions and updates.
Which bike categories benefit most from your suspension?
In principle, the suspension makes sense on all bikes that you pedal. The more suspension travel, the more noticeable the increase in efficiency.
Does Flight Attendant also give you an advantage in races?
Our approach was primarily to create a more efficient bike. We were not primarily focussing on racers. However, measurements on Strava have shown that the suspension also makes you faster.
What does the future look like? Will the brakes also work wirelessly and without any cables in a few years' time?
Even if it is certainly technically possible, the scepticism in the market would probably be far too high. We are definitely not working on it.
Looking back: Intelligent MTB suspensions and analysis tools
In the search for optimum support for the rider, the bike industry has already realised a number of ideas in terms of suspension. Only a few little helpers have been able to assert themselves and establish themselves on the market.
1. Fox Live Valve has been on the market since 2018. The high price and moderate integration prevented the wired system from gaining greater market acceptance. Live-Valve was able to impress in driving and long-term tests.
2. the Cannondale Simon System in the Lefty fork was shown back in 2009 at the Interbike in Vegas. In addition to various riding modes, the fork could even be lowered. Simon never made the leap into series production.
3. also brake specialist Magura surprised in 2015 with the electronic Chassis Electwhich even worked wirelessly like Flight Attendant and functioned in a similar way except for the missing pedalling sensor. However, due to the sampling rate of only two hertz, the landing gear works rather slowly.
4 Unlike the other automatic running gears, the Specialised Brain suspension without electronics. The purely mechanical control is achieved via a mass inertia valve, which releases the oil flow in the fork or shock when it hits an obstacle. Brain has been further developed over many years and is used in the Specialized Epic. The function is not entirely convincing.
5. the E:i-Shock chassis was fitted to bikes from Ghost from 2012, Haibike and Lapierre. Like Flight Attendant, the cable-connected system had a pedalling sensor, but worked much more slowly and was unable to establish itself on the market.
6. with the current Mondraker Mind System is an analysis tool that records suspension activity. It records the suspension travel as well as the compression and rebound speed of the fork and damper, which serves as the basis for an optimised setup.
7. also the ShockWiz system from Sram (Quarq) serves as an analysis tool for forks and shocks. By changing the air pressure of the air springs, the system provides helpful setup advice. It is conceivable that ShoxWiz will also play a part in the AXS world in the future.
