Full-power eMountain Bikes are in demand in South Africa and TREK’s new Rail+ is the latest model update that made its way to our test crew. We had it for a limited time and got to ride it on a few trails parks around Johannesburg. Here’s what we think.
THE BIKE
The Rail + is the fifth generation of the Rail platform, which has been TREK’s foundation eMTB in South Africa. Adding the + (Plus) implies there’s more to the previous version. And there is, including more suspension travel, more battery range, more adjustability and more maneuverability.
There’s also less too: Less overall battery weight, less motor weight and less motor sound. All features you’d expect when refinement happens. Oh, and there’s no more Knock Block, which we don’t mind. We understand the benefits, but just didn’t like having our steering limited and like the freedom of being able to fit any stem.
The model we tested, the 9.8 GX AXS has a TREK OCLV carbon fibre frame which has a (removable) integrated battery, internal cable routing, adjustable headset and Mino Link geometry and leverage rate adjustment. The Rail + still relies on TREK’s Active Braking Pivot (ABP) suspension design that features a concentric pivot point at the rear axle, which allows the suspension to remain active and independent of braking forces, similar to a four-bar Horst Link design.
There’s a Fox Performance Elite Float X shock with 160mm of travel and a Fox Performance Elite Float 38 fork with 160mm of travel. That’s 10mm more travel at the rear than the previous generation and more than enough travel for most South Africans. And honestly, about as much as a skilled trail rider will need in this country. It is possible to fit a 180mm travel fork if necessary.
And curiously, but appropriately, there’s a mounting point for a kickstand on the left chainstay. We’ve never fitted a kickstand on an eBike, but considering a large number of buyers of full eBikes are middle-aged and elderly riders, a kickstand option on a bike that weighs 24kg does make sense.
The colour of the frame on our test model is essentially matte black, but called Deep Smoke with some white or light grey speckles. The speckles look like leaked sealant spray. Quirky, but maybe not to everyone’s taste. We didn’t really think of it unless we were washing the bike…
In terms of the Bosch E System, there’s a Bosch Powertube 800 Wh battery, a Bosch Performance Line CX motor which delivers 85 Nm of torque and 600 Watts of peak power. It can, via the Bosch eBike Flow app (and free of charge), be tuned to offer 100 Nm of torque and 750 Watts of peak power, which is quite an impressive boost. The bike is also compatible with a Bosch range extender, which would deliver a total of 1050 Wh of ride support – right at the top end of what most modern full eBikes offer.
The Bosch wireless Mini Remote and System Controller makes for a cleaner, simpler cockpit than the previous edition. You can sync the bike to the Bosch Flow app to access more data and tune the motor’s power output.
TREK’s designers also invested in the bike’s geometry and adjustability. The Rail+ gets a fractionally steeper head tube angle (from 64.2° to 64.5°) and riders can tweak their bottom bracket height and head tube angle a half a degree thanks to Mino Link – and adjust suspension leverage rate with the flip of a chip. The Rail+ is also compatible with angle-adjust headset cups (sold separately) for going a degree slacker or steeper.
The mullet wheel setup is fixed with a 650b wheel at the back and a 29-inch wheel up front. Noticeable visually when looking at the bike from a distance, but not when mounted, while the SRAM GX Eagle AXS 1×12 drivetrain with T-Type derailleur and SRAM Code 4-piston hydraulic disc brakes complete a very solid spec. The main battery charges the SRAM AXS derailleur battery, which is quite useful.
THE RIDE
Our test rides on the Rail + were at Asidlale Adventure Park, St Stithians School trails and Delta Park – all Johannesburg trails parks with some reasonable gradient, engaging singletrack and well-made features like berms and jumps, which are essential if you’re on a bike designed to shred!
Our test model was a size Medium, ideal for our three testers who were 168cm, 172cm and 176cm. We left the geometry as we received the bike and it felt just fine for tackling technical trails, both up and down. If we were riding more gnarly, steeper trails like you get in the Western Cape, KZN and Mpumalanga, we would have adjusted the setting.
Our initial set-up had us checking the TREK suspension calculator to see what pressures and rebound settings are recommended for rider weight. We started with the suspension slightly soft and then increased it as we needed. The seattube angle feels steeper than its 75.3 degrees, which is good for climbing composure. The Rail + is very planted on climbs, both technical and steep climbs and long and steady ascents.
The 5th generation Bosch CX motor is impressive in how smooth and predictable it is, especially in the adaptive eMTB mode, which offers a natural power curve that better matches what your legs are doing. A bit like traction control on the ascents. Climbing is when you are most likely to notice motor sound and boy is this new Bosch motor noticeably softer than its predecessor. A very mild whirring is what you hear no matter how much pedal assistance you summon. Other systems often increase in volume with increased pedal assistance.
Let’s be honest, with 160mm of travel front and rear and that geometry, this Rail + is made to shred – and shred we did! The Fox Performance Elite Float 38 is an impressive fork and one of the features where the Rail + is one up on most of its rivals in this price/model segment. Not surprisingly, it combines really well with the Fox Performance Elite Float X giving the bike a really playful, trail-bike feel.
Although the rear tyre was fairly worn on the demo model we received, we appreciated the robustness of Bontrager’s newish Brevard RSL tyres. They were pleasingly grippy in dry, sketchy Gauteng winter riding conditions. More brands need to spec eBikes with robust tyres like these…
The Delta Park jump line had us doing a steeze test and the Rail + not only passed, it did so with distinction. For a full eBike the Rail + is very whipable. Full-power eBikes have the benefit of weight and a low centre of mass and therefore you expect them to be planted on corners. The Rail + is that for certain and literally rails well-made berms with a pleasing level of precision.
In terms of range, we never got to fully test the range in our short test period, but can confirm it enthusiastically offers pedal assist to 32kph. Our three longest rides were between 47-52km in distance with no restraint on the modes and each ride saw us finish with at least two bars (20%) of battery charge remaining.
The 9.8 GX AXS is the top Rail + model option in South Africa and it is priced at R169 000. There’s also a 9.7 model that has mechanical shifting which is R135 000 and then the aluminium-framed Rail + 8, which is R105 000.
(Note: Pricing is correct as at August 2025)
SUMMARY
The TREK Rail + is completely redesigned, bringing adjustability, power and control to the fore on a full carbon-fibre frame. There’s been no skimping on the spec of the 9.8 GX AXS, which delivers efficient and predictable shifting, suspension, traction and braking. While the power and range are great for recreational riders, the Rail + is primed to shred under a skilled rider. It’s definitely an improved bike allround over its predecessor and sure to appeal to a wide range of South African eBike riders.
PRICE: R169 000
SIZES: S, M (tested), L, XL
COLOURS: Deep Smoke | Pennyflake
Find out more here.
