TREK’s New ‘Rail’ Enduro E-Bike. Stronger, Harder, and 100% Bad-Ass


TREK Rail 9.9
Rail 9.9 XX1. Top Spec .e-bike from TREK

When the first version of TREK’s Rail surfaced in 2020, it was groundbreaking. Designed to target the Enduro Race market, Rail e-mountain bikes are electric powered versions of the successful TREK Slash.


Being smart, TREK didn’t completely reinvent the wheel. They took their fantastic, award winning Slash Enduro MTB and re-engineered it to handle the extra weight and power of an electric motor. Their concept was to retain as much of the agility and handling of the popular Slash, and simply add an engine and battery.


The top of the range TREK Rail 9.9 full suspension E-bike, was released with a rear-wheel travel of 150mm, and forks with 160mm travel. This was the travel preferred by most enduro enthusiasts of the day. Their top flight bike of 2020 used RockShox Lyrik’s (which were the best forks in the Enduro class at that time) and 29er wheels were chosen to comply with the Enduro sport riders demand for a smoother ride.


The original Carbon framed Rail 9.9 adopted what, at the time, was a radically relaxed geometry for a long-travel e-bike (at least from a mainstream bike manufacturer). 


I was so impressed with the original Rail 9.9 that I jokingly nicknamed it the Rock Crusher.

TREK Rail 9.9
Rail 9.9 XX1. Top Spec .e-bike from TREK


Two years on, and TREK continues to make some big adjustments to the Rail. For 2022 the advancements keep coming, each year progressing the ability of the bike.


The new model now uses the latest 160mm travel shock from RoxShox. The Super Deluxe Ultimate RT3 with redesigned DebonAir air spring. The extra travel and new spring and damper soak up a little more punishment and give a little more grip at the rear.

The front end boasts the new generation, beefier, 38mm stanchion ZEB Ultimate forks, again with DebonAir latest air spring and the latest Charger 2.1 RC damper.


ZEB Ultimate are competition crushing Enduro race forks.

These forks have proved to be extremely popular with the Enduro community over the past year. Not slow to recognise the best in industry, TREK first installed the ZEB on the 2021 models, the stronger, 21% stiffer ZEB, continues with 160mm travel.

The 2022 year RAIL 9.9 now adds RockShox Airwiz tech to their suspension. Airwiz adds tire pressure information to the plethora of information now available on the new bike. 


Pressure sensors fitted to the valve stems wirelessly feed information to red/green LED sensors in the forks that provide a visual warning that the pressure is in the correct range. The sensors can also send more detailed pressure information to your smartphone to aid precise trail setup.


It is interesting to note that ZEB forks are poised to be enhanced with RockShox Flight Attendant, the latest wireless, Artificial Intelligence suspension.


Already fitted to the Slash 9.9 XX1 AXS, it shouldn’t be long before RockShox Flight Attendant is offered as an optional upgrade on the Rail.


The move to RockShox latest Enduro racing tech shows where TREK want to position the bike. TREK are targeting the top performance e-MTBs such as the Specialized S-Works Turbo Levo, and Cannondale’s Carbon NEO.

Super-Delux Flight Attendant rear shock
The Super Delux Ultimate RT3 damper can be fitted with RockShox cutting edge Flight Attendant intelligent suspension system. Click here for details of RockShox Flight Attendant.
RockShox ZEB Ultimate forks
ZEB Ultimate forks are quickly becomeing the new "go to" for Enduro racers. Click here for more detail on RockShox ZEB forks.

Click the video above for more information on RockShox Flight Attendant A.I. suspension. 

The 2022 model increases the old 625wH battery to a massive 750wH PowerTube. This now matches the best in class top tier e-MTBs. This is the most significant update to the 2022 model.


The battery also ships with a more powerful 4.4Amp charger to reduce the recharge time.


The new Rail 9.9 has been designed to accommodate this power upgrade.


The added weight in the downtube is no doubt what prompted geometry modifications to retain the agility of other Rail models.

To enhance this upgrade, Bosch/TREK have refined the software on the Rail 9.9 to allow more control over power usage. Riders can now refine the characteristics of power support provided to the rider and have options to control the battery usage over a pre-set distance.

The software upgrades give the rider more options to maximise the benefit from the increased battery capacity. A definite WIN – WIN – WIN for power delivery, battery endurance and rider pleasure.

Although the power management app is a great additional enhancement to the battery and ride, it is still not as refined as many other battery/ride management systems on the market. Although their battery matches the best in class, TREK still has some work to do on their software.


The 2022 model still has the lock of previous generations. The RIB or Removable Integrated Battery is stylish and easy to access as it simply pops out from the right side of the downtube. The battery has a handle on top to assist carrying.


The locking mechanism is prone to wear and there have been issues with the battery dropping out on rough trails. 


There is no redesign of the locking mechanism so the additional battery weight  may be problematic after a while. Owners would be advised to check for play in the mechanism periodically before hitting rough trails.

TREK R.I.B. Battery
TREK R.I.B. batteries are easy to remove and convenient to carry. Locking mechanism should be checked for wear before riding rough trails.


The fundamentals of the fantastic 2021 Bosch Performance Line CX motor remain unchanged although the 2022 model receives a lot more adjustability with the addition of a new e-bike Flow App. The KIOX LED display is clean, and clearly displays the remaining battery power, motor power, and cadence.


TREK have refined internal cable routing to subtly reduce rattles. A reduction in noise was evident as I rode through some rough trails. I heard very little from cables clattering in the downtube. 


There is still some rattle from the powerful 85 Nm Bosch CX motor, but this is far from a distraction from the incredibly responsive power plant. 


The CX has the best climbing ability of any 250 Watt motor that I have tested. Motor power engages quickly with even the slightest pump on the pedals, and it delivers unbelievable torque. 


The Performance Line CX motor precisely feeds in power to enhance riding pleasure in all situations. There is no need to alter riding modes. I rode the engine hard on some steep trails and had no overheating issues.

Mid-mount motor kits form Bafang and Yamaha
The Bosch Performance Line CX motor pushes out 85Nm of torque. A solid achievement for a 250 Watt power plant.


As mentioned earlier, along with suspension and battery capacity upgrades, the bike geometry has also been tweaked. 


Although the long chain-stay remains unchanged, the headtube angle tightens, reach is extended, and the bottom bracket drop is reduced.


This bike is 1 Kilo heavier than its predecessor due to the stiffer, 38mm ZEB forks, and higher capacity battery. 


These are subtle improvements to the geometry of their e-MTB Enduro. The new geometry increases agility to compensate for the extra weight of the battery. Their objective was to keep the Rail adaptable and capable. The bike retains its stable, smooth, and accurate character, but gains a little agility in tight turns and sweeps. 


The adjustments make sense considering their rivals are producing more flexible and competent bikes than ever. (Note here that geometry amendments are isolated to the Rail 9.8 and 9.9 models. Rail 9.7 and below continue with last year’s geometry.


TREK have also included their Flip Chip at the top of the chain-stays (Hinges on each of the chain-stays, secured with 5mm hex bolts).


The Flip Chip allows riders to make significant adjustments to the length of the chain-stay. Adjustment can increase the planted stance if the rider wants to focus the laser accurate lines or shorten the stance for a more agile ride.


By unfastening the two hex bolts and “flipping” the chips you can extend and raise the chain-stay for better climbing geometry. The bike is more agile and there is greater pedal clearance. A better geometry for climbing steep trails.


Moving the chip back lowers and shortens the chain-stay. This slackens both the tail and headtube angle, lowering centre of gravity and extending bike length for greater stability on faster tracks.


The Bontrager Line Elite Dropper is easy to operate which allows you to lower seat height by 200mm (This is from fully extended on the XL model, smaller frames offer less drop).


The saddle is positioned quite far forward, although the forward position is more thoughtful than you would expect. The powerful Bosch CX motor allows the rider to sit more often when climbing.


The long travel loose geometry bikes took off quickly after TREK’s debut of the original Rail. What seemed novel at the time has since become normal. TREK’s newest, carbon frame, Slash 9.9 XX1, has comparable travel and geometry to the original Rail. The 2022 Rail simply a refinement of their brilliant creation.


TREK provides no less than 14 variants of the Rail. Each of these Rail models allow the purchaser to customize a range of components from suspension to handlebars, grips, and wheels.


All TREK Rail models share the same fundamentals of frame geometry and Bosch CX motor. Price reductions are achieved by replacing Carbon frames with Alloy, reduced battery capacity, and more basic running gear and suspension. 


Cutting corners in a number of areas, lets TREK build bikes to suit a wide range of budget.


The lowest price Rail 5 starts the range at one cent under $5,500 and prices go up as model numbers and specifications increase. The range tops out with the Rail 9.9 XX1 AXS which retails at $13,550.


When you double the price tag you obtain a smoother, marginally more capable version of the same bike. For example, the model weight decreases by only 1K from low to high spec (beaingin in mind the heavier battery of the top spec). But who wants to settle for a McDouble if you can afford the Quarter Pounder Cheese Deluxe?


All 14 versions are available in 3 frame sizes, and are partnered with RockShox 160mm forks throughout the range. Forks and shocks, of course, vary in stanchion diameter and damping sophistication.


This newest Rail provides riders with everything they desire at a well considered price. At $13,550, the top shelf Rail 9.9 XX1 AXS, is $500 cheaper than the highest spec ‘analogue’ Slash. It is also $9,000 cheaper than the top spec Specialized S-Works Turbo Levo.


This is an excellent, well priced, Enduro e-bike.


For most riders where the sport is an occasional week-end hobby, it is difficult to justify the top model. TREK have addressed this with the variety of models to suit most budgets. 


All Rail models are competitively priced for the spec. Every bike offers great performance, one of the strongest motors in class, and sensational presentation. The lowest spec Rail retails at $5,500 and provides a lot of bang for buck.


It is often overlooked in reviews but, I believe that TREK have nailed the look, colors, and decals on the Rail. The image of the bike is the most important factor to many purchasers and these are stunning looking e-MTBs.


The Rail 9.9 XT XX1 relies on Shimano, and Bontrager, drivetrain and components. 


Shimano XT M8120 4-piston hydraulic brakes, and RT76,  203mm rotor pulling the bike up well. The XT M8100 12 shifter, derailleur, chain, and cassette are positive and precise although the 12 speed selection.


Lightweight Bontrager Line Comp 30 carbon rims are used on the Rail. The Rail 9.9 is shod with Bontrager SE5 Team Issue tires up front and Bontrager SE6 Team Issue in the back. All other Rail models get the Bontrager XR5 Team issue front and rear.


To get a better idea of how the Rail felt I put it through its paces on a variety of terrain. From slow, rocky, unforgiving technical tracks, to fast, flowing, steeply banked sweeps, the bike was planted and precise. 


The RoxShox – Maestro combination is excellent, and, with the RockShox DebonAir spring and Super Deluxe Ultimate RT3 at the back the bike was compliant and grippy as I climbed slowly over rough steep terrain.


The Rail pedalled quickly with seamless power integration from the Bosch CX motor.  The bike pulls the rider up steep bluffs and forest trails like you wouldn’t believe.


Handling was crisp and precise on fast, chunky, tracks.

e-MTB jump action
Handling is fast and precisise, motor has lots of torque, and suspensin soaks up the hits.


The TREK Rail is first and foremost, a sensational looking bike. It hugs the ground through the gears, allowing you to rip down fast chunky trails and tear around gravelled sweeps. Its well-balanced ride and low centre of gravity keep you connected. 


It is sure footed, composed and confident to the point that it inspires recklessness. The power from the motor, and best in class battery, would keep me out on the trail for longer than I could ride.


The TREK Rail is built as an all rounder. Capable of taking on everything. Steep, quick, and jumpy tracks don’t phase the bike. The Rail is a long travel Enduro e-MTB that can rip big terrain. 


The Rail has become TREK’s premier electric mountain bike as a result of its all round capability. The latest adjustments to geometry to improve agility make sense. This keeps the bike in line with the top end competition it is targeting.


Hard as I tried, I really couldn’t find anything negative about this ride. I could have been nit picky and said that the weight compromises some of the bikes agility. But added weight is a compromise that I happily make to have the longer lasting, large capacity battery and sure footed, long travel 38 mm forks.


The bike doesn’t have the lightweight snap displayed by some elite e-MTBs but that’s a trade off I am willing to take for the massive battery and awesome, high torque motor.


This bike is built for extended fun on enduro tracks and it fulfils its design admirably.

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TREK Rail 9.9. Stronger, Harder and 100% Bad-Ass
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TREK Rail 9.9. Stronger, Harder and 100% Bad-Ass
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TREK have everything right with their latest Rail 9.9 e-MTB. Stunning looks, performance, power, battery and price. I test out the latest features and put the bike though its paces.
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Steve - Power Bicycle