On Test | The 2021 Trek Rail 9 gets 4 crucial upgrades to take it to the next level

Ooh yes, we’ve just got our dirty paws on the latest version of Trek’s big travel, full suspension e-MTB, the Rail! Essentially an electrified version of the Slash, the Trek Rail is equipped with a 160mm travel fork, 150mm rear travel, 29in wheels and aggressive 2.6in wide tyres. With an eye on big mountain terrain, the Rail’s frame is engineered around the latest 4th generation Bosch Performance CX motor and a big 625Wh battery that stows inside the downtube.

Mick travelled over to the launch of the Rail last year, and you can check out his detailed first look story here for all the ins and outs of this premium long travel electric mountain bike. While Mick was thoroughly impressed with the Rail’s handling and suspension performance, there were still a few areas for improvement. Trek appears to have been listening, because while the chassis carries over for 2021, the Rail has been updated with several key upgrades that are designed to strengthen this bike’s stance amongst an increasingly competitive field. Here we’ll be taking a closer look at our newest test bike, the 2021 Trek Rail 9, to see exactly what’s changed, and why we’re excited to put this e-MTB to the test on home soil.

Essentially an electrified version of the Slash, the Trek Rail is equipped with a 160mm travel fork, 150mm rear travel, 29in wheels and chubby 2.6in wide tyres.

2021 trek rail 9 rockshox zeb

Hello ZEB!

That’s right, the RockShox Lyrik has disappeared from the front of the Rail 9, and in its place is the all-new ZEB, an absolute monster of a fork. Featuring bigger 38mm diameter upper tubes, the ZEB is chunkier than the Lyrik and is designed for big travel enduro bikes, e-MTBs and bikepark-style riding.

The ZEB can be had with 160-190mm of travel. Here in it’s in its shortest travel guise, it gives the Rail a very robust-looking front end. Inside you’ll find the new DebonAir C1 air spring along with the ultra-tuneable Charger RC 2.1 damper, which offers adjustable compression and rebound damping. We’ve already tested the ZEB separately and it’s a brilliant fork that is a welcome addition to the Trek Rail – check out our review of the 2021 RockShox ZEB here.

The 2021 Trek Rail upgrades to the new RockShox ZEB fork and a custom Super Deluxe Ultimate shock, which places a bigger emphasis on grip and high-speed damping control over pedal efficiency. All good things for a big travel e-MTB.

2021 trek rail 9 rockshox super deluxe ultimate
Yes the adjusters are different, but it’s on the inside where the custom Super Deluxe Ultimate cooks up a little extra magic sauce.

Super Sensitive (And Custom) Super Deluxe

Another big suspension upgrade for the 2021 Trek Rail is the rear shock. It’s a custom shock built by RockShox and designed in collaboration with Jose Gonzalez – the man at the helm of Trek’s Suspension R&D lab in California. This custom Super Deluxe Ultimate shock was first announced a few weeks ago on the brand new 2021 Trek Slash, and Trek has brought it over to the Rail for 2021.

While the shock might not look all that different, it’s what’s on the inside that counts. It still uses the Thru-Shaft damper architecture, but unlike the shock used on the 2020 Trek Rail, there’s no more RE:aktiv valve. Instead, Trek has implemented a standard shim stack, with the goal of prioritising glue-like traction and warp-speed descending control over outright pedal efficiency. That makes total sense for a pedal assisted e-MTB, and in our experience with the new Slash, it’s a seriously impressive shock that should bring greater suppleness and reactivity to the back end of the Rail.

2021 trek rail 9 bosch performance cx gen 4
The 2021 Trek Rail makes use of the Bosch software update, giving the motor an extra 10Nm of torque and more responsive performance in the eMTB mode.

More Powaaah!

The Rail still features the latest Bosch Performance CX Gen 4 engine, though this motor has recently had a significant software update to provide more power and a more natural delivery of that power. There’s now 85Nm of torque (up from 75Nm), and it features an Extended Boost function, so that the motor continues to drive a little longer after you stop pedalling on a tricky technical climb. The eMTB mode has also been refined to be more sensitive to the rider’s inputs, particularly in lower gears, and power delivery is more accessible across a wider cadence range than before.

The newly refined Gen 4 motor comes standard on the 2021 Trek Rail, but it’s worth noting that for those with the 2020 version, you can achieve those same refinements with a simple software upgrade – get in touch with your local Trek dealer to inquire about the upgrade.

Purion Out, Kiox In

Also nice to see is the switch from Bosch’s functional but ageing Purion display to the much more futuristic Kiox display. The head unit sits on the Rail’s top tube just behind the stem, where it’s better protected in the event of a crash. The head unit attaches to its cradle via the sorcery of magnets, while a simple control switch near the left-hand brake lever allows you to change assist modes and scroll through menu options without having to take your hand off the grips.

The display features a sweet colour screen and access to a wider range of metrics on-the-fly, including remaining range, live power output, cadence and riding speed, and it’ll pair via Bluetooth your smartphone to update ride data.

2021 trek rail 9 emtb electric mountain bike bosch kiox
The remote offers you fingertip control of the assist mode, while the display unit is protected on the top tube behind the stem.

What Models Will There Be In Oz?

For 2021, Trek Australia will have three different models in the Rail lineup, with prices starting at $8,999 AUD for the Rail 7 and going up to $11,799 AUD for the Rail 9.8 XT.

The entry-level option is the Rail 7. This bike features an Alpha Platinum Alloy chassis, the Bosch Performance CX motor and 625Wh battery, and for 2021 it moves over to a Shimano SLX 1×12 drivetrain with 4-piston brakes. Suspension is handled by a RockShox Yari RC fork and a standard in-line Deluxe shock (the Rail 7 doesn’t get the new custom Super Deluxe Ultimate piggyback shock), and it also relies on the older Purion display.

The Goldilocks bike is what we have here – the Rail 9. It gets the same chassis, motor and battery as the Rail 7, but upgrades to the new ZEB fork and custom Super Deluxe Ultimate rear shock. As mentioned above, it also gets the new Kiox display, along with chunky 2.6in Bontrager SE5 tyres, powerful 4-piston SRAM Code brakes, and a GX Eagle drivetrain with the new derailleur and 10-52T cassette.

And finally there’s the top-end Rail 9.8 XT model. This is the only Rail model in Australia to feature an OCLV carbon fibre chassis, though the spec is otherwise very similar to the Rail 9 – the fork, shock, wheels, tyres and cockpit are identical. You do get carbon bars though, as well as a Shimano XT 1×12 drivetrain and SLX brakes. Trek claims it’s over 1.5kg lighter as a result, but you’ll be paying a $1,300 premium for that pleasure.

The Rail 9 sits in the middle of the lineup, featuring a tough alloy chassis, Bontrager finishing kit, SRAM Code brakes and the new GX Eagle 1×12 drivetrain – complete with that gargantuan 10-52T cassette.

2021 trek rail 9 bosch emtb electric mountain bike
While the frame design and geometry carry over from 2020, key updates to the Rail 9’s suspension and Bosch system promise a different experience on the trail. Stay tuned for more from our newest long-term test bike.

2021 Trek Rail 9 On Test

Over the coming summer season, we’ll be putting our Trek Rail 9 to the test to see exactly how the new changes play out on the trail. In the meantime, let us know if you’ve got any questions about the Rail 9, and read on for a closer look at the specs and our video review from the Trek Rail launch.

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