Dan reviews the new Trek Rail+ Gen 5

It was all the way back in 2019 when we first swung a leg over the original Trek Rail. That bike was a pretty dramatic step-up from Trek’s previous e-MTB, the Powerfly LT, boasting much improved handling and integration. It was also one of the first electric mountain bikes to market with the Bosch Performance Line CX Gen 4 motor, which went on to become the standard in the full-powered space.

Trek updated the Rail the following year with some key changes to the suspension and electrics, including a 10Nm bump in motor torque via a Bosch firmware update. In 2022 we then saw a new frame rolled out that featured longer and slacker geometry, along with an increase in battery capacity to 750Wh and an update to the Bosch Smart System. We reviewed the Rail 9.8 XT and came away impressed with its incredible stability and grip, but were less stoked on the rattly battery and leaky Thru Shaft shock.

It would appear that Trek has taken that feedback on board when designing the latest 5th generation Rail (now named the Rail+ to bring it into line with Trek’s other e-MTBs). This bike is brand new from tip-to-tail and looks to address some of the issues we encountered with the old bike, while further expanding on its all-round capability.

An overview of the Trek Rail+ Gen 5

The Trek Rail+ features a brand new frame for 2025 that’s produced in alloy and carbon variants. Each frame is purpose-built around a mullet wheel setup, with the exception of the size small that utilises 27.5in wheels front and rear.

Compared to the previous Rail the new bike gets a 10mm increase in rear travel, so there’s now 160mm of travel at both ends. You’ll still find the ABP suspension platform, though Trek has added a 2-position leverage rate flip chip at the lower shock mount like you’ll find on the latest Slash+. This changes progression from 19 to 24%, with the latter option being particularly well suited to a coil shock.

At the heart of the Rail+ is the latest Bosch CX Gen 5 motor. This produces the same 85Nm of torque and 600W of peak power as its predecessor, though it is significantly quieter while also being smaller and lighter. Following a similar theme, the 800Wh PowerTube battery offers increased range despite weighing nearly half a kilo less than the old 750Wh battery thanks to newer generation cells.

Frame & battery updates

Whereas many e-MTBs are moving to a fixed battery, the Rail+ still features a removable design. The battery no longer loads in from the side however, instead dropping out from underneath the downtube via a 6mm hex key. There’s also an optional tension bolt that can be added if you’re riding particularly gnarly terrain, which should lead to less of the rattling issues that plagued the previous Rail.

On the note of batteries, the Rail+ is compatible with Bosch’s 600Wh PowerTube for those who are interested in saving almost a kilo in weight. Unfortunately you can’t choose the smaller battery at the point of sale, so you’d have to purchase it separately along with the required end cap adapter.

For riders wanting more capacity the Rail+ is compatible with the Bosch range extender. Adding one of those will give you 1,050Wh of juice to play with, which would let you pack in a serious amount of riding.

Up at the cockpit you’ll find the Bosch wireless Mini Remote and System Controller, resulting in a clean and simple user interface. As with other e-MTBs that have launched with the CX Gen 5 motor, a large blanking plate surrounds the System Controller in the top tube, hinting towards compatibility with a bigger, future display option. In the meantime you can sync the bike to the Bosch Flow app to access more data and tune the motor’s power output.

Geometry & size chart

The new Trek Rail+ features similar geometry to its predecessor and maintains the same four size lineup. Unfortunately there is no M/L size (like you’ll find on the non-motorised Fuel EX and Slash), which means there’s a hefty 40mm jump in reach between the Medium and Large. As a result, riders in the 175-180cm height range may need to compromise and size up or down from their preferred fit.

A notable change in the geometry chart is the move to a slightly steeper 64.5° head angle. However, since the Rail+ adopts the modular headset cups we’ve seen on other Trek mountain bikes, you’re able to slacken or steepen the head angle by a full degree.

There’s also a 2-position Mino Link in the rocker link for further tweaking. Bikes ship in the Low position and flipping it into High will steepen the angles by 0.5° and lift the BB by 7mm.

Trek Rail+ price & specs

At the time of launch there will only be two Trek Rail+ models available in Australia. Given how popular this model is for Trek however, we expect that range to grow in the future.

Currently the cheapest option is the Trek Rail 8, which retails for $8,999 AUD. It features an alloy frame and an appealing spec that includes a RockShox Zeb fork and Super Deluxe shock, SRAM DB8 brakes and a Shimano 1×12 Deore drivetrain. The only component we’d consider changing right off the bat is the thinner casing Bontrager XR tyres, otherwise it looks like a solid bike for the money.

Our test bike is the Trek Rail 9.8 GX AXS model, which sells for $11,999 AUD. The extra cash gets you a lighter OCLV carbon frame, SRAM’s wireless electronic GX AXS Transmission, Fox Performance Elite suspension and beefier Bontrager SE casing tyres.

2025 Trek Rail+ 9.8 GX Gen 5

• Frame | OCLV Mountain Carbon, ABP Suspension Design, 160mm Travel
• Fork | Fox 38, Performance Elite, GRIP X Damper, 160mm Travel
• Shock | Fox Float X, Performance Elite, 205x65mm
• Motor | Bosch Performance Line CX Gen 5, 85Nm
• Battery | Bosch PowerTube 800Wh
• Wheels | Bontrager Line Comp 30, Alloy Rims, 30mm Internal Width
• Tyres | Bontrager Brevard RSL SE, 29×2.5in Front & 27.5×2.5in Rear
• Drivetrain | SRAM GX AXS Transmission 1×12 w/GX Crankset & 10-52T Cassette
• Brakes | SRAM Code Bronze 4-Piston, 220mm Front & 200mm Rear HS2 Rotors
• Handlebar | Bontrager Line Pro, OCLV Carbon, 27.5mm Rise, 780mm Width
• Stem | Bontrager Line Pro, 45mm Length
• Seatpost | Bontrager Line Dropper, 34.9mm Diameter, Travel: 150mm (S), 170mm (M), 200mm (L-XL)
• Claimed Weight | 24.18kg (Medium)
• Actual Weight | 24kg (Large)
• Price | $11,999 AUD

2025 Trek Rail+ 8 Gen 5

• Frame | Alpha Platinum Alloy, ABP Suspension Design, 160mm Travel
• Fork | RockShox ZEB Select Charger RC Damper, 160mm Travel
• Shock | RockShox Super Deluxe Select+, 205x65mm
• Motor | Bosch Performance Line CX Gen 5, 85Nm
• Battery | Bosch PowerTube 800Wh
• Wheels | Bontrager Line Comp 30, Alloy Rims, 30mm Internal Width
• Tyres | Bontrager Brevard Pro XR, 29×2.5in Front & 27.5×2.5in Rear
• Drivetrain | Shimano Deore 1×12 w/e*13 E*Spec Plus Crankset & 10-51T Cassette
• Brakes | SRAM DB8 4-Piston
• Handlebar | Bontrager Line Alloy, 27.5mm Rise, 780mm Width
• Stem | Bontrager Elite, 45mm Length
• Seatpost | Bontrager Line Dropper, 34.9mm Diameter, Travel: 150mm (S), 170mm (M), 200mm (L-XL)
• Claimed Weight | 25.08kg (Medium)
• Price | $8,999 AUD

Trek Rail+ weight

Our Trek Rail + 9.8 GX AXS test bike weighs in at bang-on 24kg (set up tubeless and without pedals), which is a smidge heavier than the previous Gen 4 version.

Despite the increased capacity, the 800Wh PowerTube battery is actually half a kilo lighter than Bosch’s old 750Wh version thanks to the use of new generation lithium-ion cells. Trek has then added that weight back on by spec’ing much burlier DH-ready tyres. The new Bontrager Brevard RSL SE tyres feature thicker casings that sees them tipping the scales at around 1.4kg for the front and 1.2kg for the rear.

This is awesome to see, and we’re glad that more bike brands are fitting burlier components to their e-MTBs to stand up to the abuse that they’re capable of. It does mean that weights for full-powered bikes are going up, with the latest Specialized Levo 4 and Focus JAM² now hovering around the same 24kg mark. The sub-21kg Amflow PL Carbon is a notable outlier, though that bike does feature a much lighter frame, a skinnier Fox 36 fork and thinner casing tyres. The battery is also bolted inside the downtube and isn’t designed to be easily removed, which helps to reduce weight at the expense of practicality.

Ultimately, when it comes to a full-powered e-MTB with a big 800Wh battery, we expect weight won’t be much of a concern for most riders. Once you’re over the 20kg barrier, the main priorities are likely to be power, range and descending capability.

So, how does the Trek Rail+ stack up in that regard?

Testing the Trek Rail+ 9.8 GX AXS

To give the 5th generation Trek Rail+ a thorough workout, we put it into the hands of our enduro and e-MTB tester Dan.

Dan spent a lot of time on the previous versions of the Rail, both in alloy and carbon flavours. More recently he tested the Amflow PL Carbon, and after having handed that bike back he was very keen to see how the new Rail+ with the latest Bosch CX motor would compare on the trail.

Here we chat with Dan about his experience of riding the Rail+ 9.8 GX AXS test bike over the past few weeks.

How have you found the overall sizing & fit?

I’m 183cm tall and the size Large has felt perfect. The 490mm reach is slightly longer than the old bike, but with the saddle set to my pedalling height, the effective seat tube angle is quite a bit steeper and places you further forward in the cockpit. As a result, I haven’t had to slam the saddle forwards on its rails like I did with the old Rail.

It’s been a comfortable bike to ride and I have no complaints from any of the contact points. I like that the bars come standard at a reasonable width of 780mm, and not 820mm like Trek used to spec on the older models. The bar height and sweep felt nice, as did the Bontrager grips and saddle. The dropper post worked as it should and I was happy to see a generous 200mm of travel spec’d on the size Large.

The rest of the geometry is pretty spot on. The Rail+ feels great on the descents, and its manoeuvrability is impressive given its weight. I think a lot of that is due to the mullet wheels, which makes it quite playful and with a fair input you can even manual (almost).

Talk us through your suspension setup

To help you get the Rail+ setup before hitting the trails, it’s worth checking the Trek suspension calculator to see what pressures and rebound settings are recommended for your weight. While it might not be perfect, it’s great that Trek is at least making the effort in the first place when many other brands leave you to figure it out on your own.

In my case I found I needed a bit less pressure in the shock to hit the recommended 30% sag. I set rebound damping a bit quicker than halfway (8/14 clicks) and ran the low-speed compression dial in the middle (5/10 clicks).

The two-position flip chip in the lower shock mount allows you to increase progression without having to open up the shock to change volume spacers. I left the chip in the ‘Less’ progressive setting (19%) as I found the rear end to deliver adequate support out of the box, though it’s cool to have the option for those who are after more ramp-up.

The 38 GRIP X fork is similarly easy to setup thanks to its single rebound dial. Once you have pressure and rebound sorted, we recommend putting the high and low-speed compression adjusters in the middle of their range and tune to taste from there. Through testing I ended up backing off the high-speed dial a few clicks to open up the fork and better match the rear suspension.

What do you dig about the Trek Rail?

We’ve always found the Trek Rail to be a great all-rounder, and that remains the case with the new Gen 5 version.

Like its predecessor, the suspension on the Rail+ is smooth and active whether you’re hard on the brakes or hammering the pedals through a rock garden. The extra 10mm of rear travel gives it an even floatier ride quality that erases impacts of all shapes and sizes, though it still manages to provide good response to rider inputs.

Helping in that department is the dedicated mullet setup. The Rail+ is super fun on the descents, with the 27.5in rear wheel and not-crazy slack 64.5° head angle making it playful and easy to change direction. Likewise, the low-hanging BB keeps you nicely integrated between the hub axles, adding to the overall stability when ripping through turns and sending it downhill. The whole bike is impressively solid and planted when being pushed at speed, and there’s loads of support from the suspension to make the most of it.

Despite the smaller rear wheel, the Rail+ climbs really well. The seated position is improved thanks to the steeper seat angle, and the 448mm rear centre length strikes a nice middle ground for weight distribution. It’s short enough to keep things nimble, but isn’t so short to make you feel like you’re going to tip over like a turtle on really steep climbs.

I didn’t find there to be too much of a compromise with the mullet setup. In fact, when faced with a multi-line uphill puzzle, it helps with changing direction when you need to zig-zag around various obstacles. Of course a full 29er will be grippier and more planted on chunky straight-line sections, but since there is so much traction available from the supple suspension and chunky tyres, the Rail+ is able to muscle its way up some pretty horrendous terrain when needed.

Initial concerns about pedal strikes due to the low 338mm BB height never quite played out in the real world. Trek has spec’d stubby 160mm crank arms on the Rail+, and the rear shock rides high enough in its travel that I was able to spin the pedals freely most of the time. Of course you could always flip the Mino Link into the High position to get another 7mm of clearance if needed.

What about the Bosch CX Gen 5 motor?

This was my first experience with the 5th generation Bosch CX motor and I have to say that I’m really impressed. I don’t think it feels any more powerful than the previous version, and it doesn’t have the buck-wild pull of the DJI Avinox motor, but the way it delivers its support is incredibly smooth and predictable. That’s especially the case in the adaptive eMTB mode, which offers a natural power curve that better matches what your legs are doing. This makes it easy to modulate power to the rear wheel, which leads to more usable grip and less chance of the bike lurching out from underneath you. This was something I appreciated when scaling some of the trickier climbs on my local trails, which have been especially loose and dusty after a dry summer.

Compared to the old motor, the way the power rolls on when you accelerate and the way it cuts off when you reach the 25km/h speed limit is noticeably less jerky. And it’s quiet, so beautifully quiet! There’s a small amount of rattle from the internal freewheel, but it is barely detectable when riding.

I was also happy to find that there was no movement or noise from the battery either. Combined with the thick downtube armour, hard plastic motor skid plate and generous chainstay protection, the Rail+ is well-damped on the descents. There is some squishing from the GRIP X damper in the fork, but aside from that it’s just the sweet sound of tyres rumbling across dirt. Nice!

What could be improved?

Honestly, there was very little that let me down on the Trek Rail+. It’s a really fun bike to ride thanks to its balanced handling and mullet setup, though the plush suspension and appropriately burly build kit means it still handles the rough stuff with aplomb.

I also like that there’s plenty of adjustability for tuning it to your needs. I got along just fine with the stock geometry, but it’s cool that you can slacken the head angle to 63.5° if you’re doing more gravity-based riding. You do need to purchase the offset cups to be able to do that, and specific tools are required to remove and install the lower cup. This means it’s not as simple as it is with the Specialized Levo for example, but the option is still there for the tweakers.

Those who are looking to slacken the head angle might also want to consider fitting a 170mm or even a 180mm air spring to the Fox 38, since the Rail+ is approved for it. Along with a coil shock, you could build yourself a pretty mean self-shuttling gravity rig.

While there is plenty of adjustability, it’s worth noting that Trek uses a fixed chainstay length across the size range. I imagine the 448mm rear centre might be too long for shorter riders on the size Small and, conversely, taller riders on the XL might want a bit more length. Given a dropout flip chip would be difficult to build around the ABP suspension design, we’d love to see Trek implement size-specific rear centre lengths as it does with the non-motorised Slash.

Component highs & lows

At $11,999 AUD the Trek Rail+ 9.8 GX AXS offers a solid package for the money that compares favourably amongst the competition. It is notably cheaper and better spec’d than the Specialized Levo 4 Comp ($12,900 AUD), the Santa Cruz Vala C S ($12,999 AUD) and the Norco Sight VLT CX C2 ($12,999 AUD). The Merida eOne-Sixty 8000 comes in at the same price, but we imagine a lot of e-MTB customers will prefer the Bosch CX motor and bigger 800Wh battery on the Rail+.

As for the parts on our test bike we have few complaints. The SRAM GX AXS Transmission has been reliable and the Code brakes offer a smooth lever feel with plenty of power thanks to the big HS2 rotors. We expected to see Mavens fitted to a big e-MTB like this, but weren’t at all disappointed by the performance and consistency of the Codes.

The Bontrager tyres deserve a shout-out for their impressive durability that saw no punctures throughout testing despite the lack of tubeless inserts. The updated triple rubber compound also delivers heaps more grip and damping compared to the old SE6 and SE5 tyres that came on the previous Rail.

The Fox suspension is another notable highlight. Combined with the ABP platform, the Float X shock offers great sensitivity that enhances comfort and traction while still being poppy enough to keep the Rail+ feeling lively on flowy sections of trail. Unfortunately the lower shock bushing developed a small amount of play after the first 100km of riding. Given how quick that occurred, and the fact that we’ve not encountered such an issue with any other Fox shock or Trek mountain bike over the last few years of testing, it’s likely to be a one-off.

The only other hiccup was with the battery release mechanism. This requires a short rotation with a 6mm hex key, though on occasion we found the battery wouldn’t pop out of the downtube. There’s a bit of movement to the locking barrel on our test bike, so wiggling the hex key is sometimes needed to actuate the mechanism. It’s no big deal, and thankfully it has no bearing on retention of the battery itself, which is locked down securely within the downtube.

The rest of the bike is otherwise well finished and Trek backs it up with a lifetime warranty for the original owner. While we didn’t have any wet weather to test them out, it’s cool to see mudguards included as standard. The rear is particularly beefy and will help to protect the main pivot from getting smothered with muck. Cable noise and vibration is mitigated thanks to snug rubber ports and internal guide tubes, and we like that you can route the rear brake hose around the head tube whether you run it on the left or right.

Trek Rail+ vs Amflow PL Carbon

It is literally impossible to review an e-MTB these days without someone comparing it with the Amflow PL Carbon. Thanks to its outrageously powerful DJI Avinox motor and low weight, the Amflow has rapidly become one of the most desirable options on the market. So how does the Trek Rail+ compare to its groundbreaking Chinese competitor?

While not exactly an apples-to-apples comparison, the Amflow PL Carbon Pro that we tested sells for $2,000 AUD more than the Trek Rail+ 9.8 GX AXS. The extra cash nets you an upgrade to blingy Factory Series suspension, a SRAM X0 Transmission and carbon wheels. The fancier spec and light-duty tyres also result in a hefty 3.6kg weight reduction, with the Amflow PL Carbon Pro being one of the lightest full-powered e-MTBs on the market at 20.42kg with an 800Wh battery.

On the trail, the DJI Avinox motor pulls ahead of the pack with up to 120Nm of torque and 1,000W of peak power in the bonkers Boost mode. If you’re after maximum acceleration and support, few motors will give you the same sensations as the Avinox M1 drive unit. The rest of the DJI system works well too, including the superb touchscreen display and user-friendly app.

There are some downsides however. There’s currently no range extender and the 800Wh battery isn’t designed to be easily removable. That will make it a non-starter for some riders, along with the fact that Amflow isn’t as readily available in all countries.

Swinging in Trek’s favour is its comprehensive dealer support network, and that goes for the Bosch motor and electrics too. And while DJI has the edge when it comes to outright power and its slick user interface, if the internet rumour mill is to be believed, Bosch will have a firmware update coming this year that will boost torque and power for the CX motor. There’s apparently a new top tube display in the works too, which will fit into the space that’s currently occupied by a blanking plate.

As for the overall ride quality, the Amflow PL Carbon Pro impressed us with its sporty and agile handling that sees it performing well across the board. However, whereas the Amflow felt more like a trail bike, the Rail+ gives off proper enduro vibes thanks to its plusher suspension, sturdier chassis and gravity-oriented build kit. It’s also a lot more adjustable thanks to the swappable headset cups, Mino Link and leverage rate flip chip. Add in the option of fitting a coil shock and a 180mm travel fork, and it’s for sure the better option for those wanting a self-shuttling bikepark rig.

Flow’s Verdict

We’re happy to report that the new Trek Rail+ carries over a lot of what we liked about the previous version while also addressing some of our criticisms.

Moving away from the side-entry battery has resulted in a much more secure retention system that has proven to be pleasingly quiet throughout testing. There’s less noise from the new Bosch motor too, and we’re big fans of the dedicated mullet setup that makes the Rail+ even more fun to ride.

Combined with the extra rear travel and numerous geometry and suspension adjustments, the Rail+ isn’t just a better performing e-MTB, it’s more adaptable too. The stock setup is likely to work well for a lot of riders, though the ability to extend the fork travel and slacken out the head angle means you can turn it into a proper DH-sled. There’s also the option of fitting a range extender to increase total battery capacity to a whopping 1,050Wh, or you could go the other way and swap in a smaller 600Wh battery to drop some weight. Whichever way you go, the Rail+ is a throughly capable e-MTB that is going to appeal to a broad cross-section of riders.

ABOUT THE REVIEWER - Dan MacMunn

Hometown

Spring Gully, Victoria

Height

183cm

Weight83kg