TREK Rail 9.9 XX1 AXS Review

The greatest long-travel electric mountain bike from Trek is the Rail 9.9. You get a powerful Bosch Performance Line CX motor with an extra-long range battery, the new smart system LED remote and Kiox display that pair with the eBike Flow app to give you activity tracking, navigation, and Bluetooth connectivity, as well as an incredibly smooth RockShox suspension system, SRAM’s best wireless electronic drivetrain, and an especially beefy carbon frame.


ModelRail 9.9 XX1 AXS
TypeElectric Bike


Check specifications here



NEW OCLV Mountain Carbon main frame, 1.8” lower head tube, Removable Integrated Battery (RIB), Knock Block 2.0, guided internal routing, 34.9mm seat tube, magnesium rocker link, Motor Armor, Mino Link, ABP, Boost148, 12mm thru axle, 150mm travel
ForkRockShox ZEB Select+, DebonAir spring, Charger 2.1 RC damper, eMTB optimized crown, tapered steerer, 44mm offset, Boost110, 15mm Maxle Stealth, 160mm travel
ShockRockShox Super Deluxe Ultimate RT3, DebonAir spring, Thru Shaft 3-position damper, 230mm x 57.5mm
Max compatible fork travel170mm (580mm axle-to-crown)

Wheel front

Bontrager Line Comp 30, Tubeless Ready, 6-bolt, Boost110, 15mm thru axle
Wheel rearBontrager Line Comp 30, Tubeless Ready, Rapid Drive 108, 6-bolt, Boost148, 12mm thru axle
Hub frontBontrager alloy, sealed bearing, alloy axle, 6-bolt, Boost110, 15mm thru axle
Hub rearBontrager alloy, sealed bearing, 6-bolt, Rapid Drive 108, Shimano MicroSpline freehub, Boost148, 12mm thru axle
Skewer rearBontrager Switch thru axle, removable lever
RimBontrager Line Comp 30, Tubeless Ready, 28-hole, presta valve
Tires: Size: S, M, L, XLBontrager SE5 Team Issue, Tubeless Ready, Core Strength sidewalls, aramid bead, 120 tpi, 29×2.50”
Tires: Size: S, M, L, XLBontrager SE6 Team Issue, Tubeless Ready, Core Strength sidewalls, aramid bead, 120 tpi, 29×2.50”
Tire partBontrager TLR sealant, 6oz
Rim stripBontrager TLR
Max tire sizeFrame: 29×2.60″ Fork: See manufacturer


SRAM GX Eagle AXS, 12 speed
Rear derailleurSRAM GX Eagle AXS
CrankSRAM X1 1000, 34T, 165mm length
CassetteSRAM Eagle XG-1275, 10-52, 12 speed
ChainSRAM GX Eagle, 12 speed
PedalVP-536 nylon platform
Max chainring size34T


Bontrager Arvada, austenite rails, 138mm width
Seatpost: Size: SBontrager Line Elite Dropper, 100mm travel, MaxFlow, internal routing, 34.9mm, 345mm length
Seatpost: Size: MBontrager Line Elite Dropper, 150mm travel, MaxFlow, internal routing, 34.9mm, 440mm length
Seatpost: Size: LBontrager Line Elite Dropper, 170mm travel, MaxFlow, internal routing, 34.9mm, 485mm length
Seatpost: Size: XLBontrager Line Elite Dropper, 200mm travel, MaxFlow, internal routing, 34.9mm, 550mm length
HandlebarBontrager Line Pro, OCLV Carbon, 35mm, 27.5mm rise, 780mm width
GripsBontrager XR Trail Elite, nylon lock-on
StemBontrager Line Pro, 35mm, Knock Block, Blendr compatible, 0 degree, 45mm length
HeadsetKnock Block Integrated, cartridge bearing, 1-1/8” top, 1.8” bottom
BrakeSRAM Code R 4-piston hydraulic disc
Brake rotor: Size: S, M, L, XLSRAM CenterLine, 6-bolt, round-edge, 180mm
Brake rotor: Size: S, M, L, XLSRAM CenterLine, 6-bolt, round edge, 200mm
Battery: Size: SBosch PowerTube 625Wh, smart system
Battery: Size: M, L, XLBosch PowerTube 750Wh, smart system
ChargerBosch standard 4A, 110V, smart system
Controller: Size: S, M, L, XLBosch Kiox 300, smart system
Controller: Size: S, M, L, XLBosch LED remote, smart system
MotorBosch Performance Line CX, smart system, magnesium motor body, 85 Nm, 20 mph or 32 km/h max assist (25 km/h max assist in EU and APAC)


M – 23.40 kg / 51.59 lbs (with TLR sealant, no tubes)
Weight limitThis bike has a maximum total weight limit (combined weight of bicycle, rider, and cargo) of 300 pounds (136 kg).
If you want to spend every penny on your e-MTB experience, this is the option for you. You want the greatest electric support that you can get in terms of adjustability, performance smoothness, range, and technology. You want wireless electronic shifting, all the interesting features of the Bosch smart system, and you want personalization. With an improved OCLV Mountain Carbon frame with extended reach and enlarged head tube and seat tube for optimal strength, it elevates technological innovation to a new level. RockShox ZEB Ultimate fork, RockShox Super Deluxe Ultimate Thru Shaft shock, and SRAM XX1 AXS drivetrain are all highly adjustable. With the new Bluetooth® LED remote for simple connectivity, the eBike Flow app’s all-in-one navigation and activity tracking, as well as TyreWiz and AirWiz pressure monitoring, you get Bosch’s innovative smart system Performance Line CX.


OCLV Carbon Frame

When compared to metallic materials, a well-constructed carbon frame significantly saves weight while preserving the strength and stiffness required by high performance bicycles and the riders that ride them. This is where Trek’s OCLV Carbon process, which stands for “Optimum Compaction Low Void,” comes into play. Starting with the best material available, OCLV Carbon frames are made. Trek has perfected the manufacturing of numerous weights and types of carbon fibre over the course of countless development hours (cloth, unidirectional, etc.).

The Trek Rail 9.9 XX1 AXS features an Active Braking Pivot (ABP) on the rear axle and a RE:aktiv Thru Shaft rear shock. It also has a full OCLV Mountain carbon fibre frame and magnesium rocker link that provides 150mm of travel.

While many of Trek’s products have five frame sizes, the Rail 9.9 XX1 AXS, given its premium status, only has three sizes and three opulent colour options. The bike has a lot of adjustability when you take into account the flip chip, which can be used to shorten or extend the rear swing arm. If you like, you may run it with the stock 29″ x 2.5″ tyres or with 27″ tyres and a mix for a mullet setup.

Bosch Performance Line CX motor

Smart Device The Bosch Performance Line CX motor is much more potent (up to 85nm of torque), responsive (measuring pedal cadence, torque, and rear wheel speed 1,000 times per second), offers shift detection to lessen drivetrain wear, is lighter than previous generations thanks to a magnesium body (weighing just 6.39lbs), and is much quieter than the majority of the older Performance Line motors! This device is amazing.

Appreciate how Trek positioned the back wheel speed magnet onto the left side of the rear hub, which has adequate venting and drainage, and metal protection beneath the Bosch CX motor (with the sensor mounted on the chain stay).

The ability of the Bosch Performance Line motors to support greater pedal rates without fading out is a feature that I truly value. You may pedal at speeds of up to 120 RPM (pedal strokes per minute) and the motor will still be working for you. This is crucial if you want to spin quickly rather than pedal particularly hard when you approach a challenging climb.

Bosch Smart System

A very individualised eBike experience is made possible by the clever Bosch eBike Systems system, which consists of the eBike Flow app, control unit, display, rechargeable battery, and Drive Unit. The latest system generation, which combines technically superior eBike components with digital features, raises the bar for riding, whether for daily use or just for enjoyment.

The outstanding Performance Line CX motor with 85Nm maximum torque is complemented by the 2022 Trek Rail 9.9 XX1 AXS, extremely advanced Bosch Smart System. The fully networked, LED-lit control centre links everything together, automatically updating the software over-the-air, letting the user access a wide range of features and customize the assist mode settings from their phone, tracking activities automatically, and even providing theft protection capabilities. This software offers navigation so you don’t need to add an external cycle computer, and it integrates with third-party apps like Apple Health and Strava to provide them data from your rides.

RockShox AirWiz and Quarq TireWiz

The SRAM RockShox clickers are the easiest to use and configure of any air suspension ever created. With front stanchions that are 38mm wide and black anodized, both shocks can withstand extended travel of 160mm without the need for a triple crown. A single thru-piston is used in place of a gas chamber in the newly designed rear shock. The rear shock features a numbered clicker that is simpler to configure and tune, and both shocks have a rebound adjuster. The rear shock has +0 and – with an on/off lockout, while the front shock has high speed and low speed compression.

SRAM AirWiz smartphone app helps you configure the proper air pressure range and alerts you with a red blinking LED when they need adjustment.

Without the ability to run a mullet setup, a pair of 29″ wheels are installed across the size range. However, there is a Mino Link adjustment chip on the seatstays that may be used to quickly modify the geometry to suit the ride.

Removable Integrated Battery & Range

RIB is a one-piece battery and cover with a built-in handle that can easily be removed and re-installed in the frame with no tools and no hassle. It’s the most convenient way to remove your battery for transport, security, or just easier charging.

The Bosch PowerTube 750 has a capacity that is 20% greater than the Bosch PowerTube 625, enabling longer rides and continuous high-power use between charges.

Bosch e-bike battery chargers are small, quick, and not too heavy. the Smart System charger, which produces 4 amps compared to most rival systems’ 2 amps. Since the cells don’t need to be perfectly balanced when starting out, a half-fill from zero only takes 2 hours, compared to a full charge expected to take 6 hours. You can charge on or off the bike thanks to the charger’s custom plug interface, which connects to the battery’s base or the bike’s frame.

Check out Bosch’s range calculator to determine how far you can travel on an electric mountain bike with one charge. You can make changes to achieve your most precise estimate even if we’ve pre-filled the data for this bike model and the typical rider. Calculate your range here.

RockShox Super Deluxe with Thru Shaft

Together, Trek and RockShox extensively redesigned and developed a superior suspension system. RockShox improved the shock while Trek developed the bicycle. Trek made adjustments to the bike while RockShox improved the shock, always utilizing their tight collaboration to produce the smoothest ride. The brand-new Super Deluxe ThruShaft was designed with a go-anywhere, ride-anything mentality, making it the perfect complement to the upcoming generation of powerful all-mountain enduro bikes.

With the use of a new low speed adjustment, the Super Deluxe ThruShaft can cancel rider inputs like pedal strokes without effecting high speed compression inputs from the terrain, such threatening, jagged pebbles.

Three settings are available in the revised low speed compression adjustment to help you discover the ideal fit for your riding style and environment.

You’ll have to drag your tail down that trail! Things are going to come at you quickly! The most extreme descents can be handled by this new shock. This shock will help you deal with all those entertainingly terrible creatures that spring up from the trail.

SRAM Hydraulic Disc & Centerline

SRAM has granted Trek two 9.9 exclusives. Both the RE:aktiv Thru Shaft Super Deluxe rear shock and Zeb Ultimate fork, which are exclusive to Trek, use AirWiz Bluetooth pressure sensors. These enable you to determine your desired fork/shock air spring pressures and then configure them in the SRAM AXS mobile app. Depending on whether you are in the sweet spot, LEDs on the AirWiz fork top cap and shock top block will then glow green or red. The tyre pressure on each wheels is measured using the identical TireWiz 2.0 valve sensors. In order to work with the Bontrager Line Pro carbon rims, these versions are likewise specially designed.

SRAM CODE RSC brakes, which include a 220 mm front rotor and a 200 mm rear disc, provide consistent bite point, forceful deceleration, and superb modulation even on lengthy descents.

Although the bike comes with a Bontrager cable-driven post, you should also acquire a RockShox Reverb AXS wirelessly operated post. Top-tier Bontrager (Trek’s own brand) is also used for the remainder of the equipment. This features its SE5 and SE6 Enduro tyres in 29 x 2.5in sizes, carbon 780mm bars, and a stem that is 45mm on all sizes. With a battery this big, the total weight of the bike is still astonishingly low at just over 22kg.

Custom eMTB Lite mode

Instead of a Tour mode, Trek eMTBs have a unique eMTB Lite mode. You get longer battery life and more natural-feeling power delivery.

Oh! What a feeling

With a new Bluetooth-connected LED remote and the eBike Flow app, Bosch’s updated smart system gives you the same amount of power and responsiveness while giving you even more control and customization options.

The redesigned frame is more durable, with a 34.9mm seat tube to accept dropper posts that are more robust and a bigger head tube that works with forks designed specifically for eMTBs to reduce flex and improve steering.

The Trek Removable Integrated Battery (RIB) system is incredibly user-friendly and stylish. It protects the battery by completely encasing it in the frame, makes it simple to remove the battery without any tools, and allows you to mount a water bottle cage.

You can quickly and easily verify that the tyres, fork, and shock are at the proper pressure with TyreWiz and AirWiz. No need to remove the pump or gauge to check anything

Pros & Cons


Easier internal cables routing

Bosch biggest battery, powertube 750

Oversized 34.9 dropper post

Bosch Kiox 300 display is tough and compact

Active braking pivot, allows suspension to work freely

Carbon care wheel loyalty program

Complete tubeless system

Chain-stay mounted sensors


AirWiz recommendations are off

Expensive bike

Battery fitting is not up to the mark


How much does the trek rail 9.9 XX1 AXS weight?

Trek Rail 9.9 XX1 AXS weighs around M – 23.40 kg / 51.59 lbs. (with TLR sealant, no tubes)

How do I know my size for Trek Trail 9.9 XX1 AXS?

The charts below illustrate our suggested sizes based on height, but other elements, such as arm and leg length, can affect how well something fits. You’ll see some overlap in our suggestions as a result. For example, not every rider who is 5’8″ will fit on the same size bike. Consult the specialists at your neighbourhood retailer for the greatest advice on finding your ideal fit.

SizeRider HeightInseam
S153 – 166.5 cm5’0.2″ – 5’5.6″72 – 79 cm28.3″ – 31.1″
M161 – 175 cm5’3.4″ – 5’8.9″76 – 82 cm29.9″ – 32.3″
L174 – 188 cm5’8.5″ – 6’2.0″82 – 88 cm32.3″ – 34.6″
XL186 – 196 cm6’1.2″ – 6’5.2″87 – 92 cm34.3″ – 36.2″

Where are Trek OCLV frames made?

Trek has developed the world’s best carbon fibre bicycles in Waterloo, Wisconsin, the USA, using an unique carbon fibre technique called OCLV Carbon.

From where I can get Trek Trail 9.9 XX1 AXS?

Trek Rail 9.9 XX1 AXS can be directly purchased from Trek.



Total score

Our Rating​

Top-tier technology is the focus of Rail 9.9 XX1 AXS. The greatest enduro fork from RockShox, the largest battery from Bosch, XX1 AXS’s smooth shifting, an updated frame, pressure monitoring from TyreWiz and AirWiz, and the newest technology from Bosch with a smart system.

Trek’s Rail 9.9 XX1 AXS is a truly amazing superbike with lightweight and quick, yet unwaveringly confident and controlled, Bosch Smart System improved performance, despite having more features than is absolutely necessary.

With a retail price of $13,799, the premium Rail 9.9 XX1 AXS reviewed had a construction deserving of flagship status. An AirWiz-equipped RockShox ZEB Ultimate 160mm fork and Super Deluxe Thru Shaft shock are in charge of the suspension. The XX1 Eagle AXS drivetrain, CODE RSC brakes, and Race carbon crank are all provided by SRAM. With their Line Pro Carbon handlebar and aluminium stem; Avada seat; Line Pro carbon wheelset; and SE6/SE5 Team Issue tyre pairing with TireWiz pressure monitoring technology, Trek’s in-house component company Bontrager completes the specification.

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Our articles are developed after considerable research and studies online and also including seeking informational experience based tips from professional rides. Key sources of information are interviews, google search and youtube.