Trek Rail 9.9 XX1 AXS Gen 4
Pedal-assist, rated to 250W, assist cuts at 25 km/h. Declared by the brand; declaration not independently sighted.
Trek Rail 9.9 XX1 AXS Gen 4 (2023) at a glance
The Trek Rail 9.9 XX1 AXS Gen 4 (2023) has Bosch Performance Line CX (85Nm) with a 750Wh battery, oclv mountain carbon, 160mm front / 150mm rear full suspension, SRAM XX1 Eagle AXS, 10-52 and SRAM Code RSC 4-piston hydraulic disc.
The Trek Rail 9.9 XX1 AXS Gen 4 is a trail emtb e-bike sold in Australia at $9,599.99 (price checked 28 Sep 2026). It pairs a Bosch Performance Line CX mid drive motor with 85Nm of torque, a 750Wh battery, 29 inch wheels, and weighs 23.6kg. It is listed as a 250W pedal-assist e-bike limited to 25 km/h for Australian roads.
Is it for you?
Best suited to
Buyers hunting a heavily discounted previous-generation carbon Rail.
Standout strength
Carbon frame and SRAM XX1 AXS at $9,599.99, down from $15,999.99.
The main compromise
Older Gen 4 frame with a 750Wh battery; one size and colour left online.
Full specification
Drive and power
Frame and ride
Australian compliance
Pedal-assist, rated to 250W, assist cuts at 25 km/h. Declared by the brand; declaration not independently sighted.
Rail 9.9 XX1 AXS Gen 4 vs Marlin+ 8
| Trek Rail 9.9 XX1 AXS Gen 4 | Trek Marlin+ 8 | |
|---|---|---|
| Price | $9,599.99 | $3,799.99 |
| Motor | Bosch Performance Line CX, mid drive | Bosch, mid drive |
| Torque | 85 Nm | 50 Nm |
| Battery | 750 Wh | 400 Wh |
| Claimed range | TBC | TBC |
| Weight | 23.6 kg | 21.9 kg |
| Frame | OCLV Mountain Carbon, 160mm front / 150mm rear full suspension | hardtail |
| Wheels | 29 inch | 29in (XS and S sizes use 27.5in) |
| Category | Trail eMTB | Trail eMTB |
| Availability | Check local dealer | Out of stock |
Choose the Rail 9.9 XX1 AXS Gen 4 if
its battery is 350 Wh bigger, so you charge less often on long rides; it has 35 Nm more torque for steep hills and heavy loads.
Choose the Marlin+ 8 if
it costs $5,800 less; it is 1.7 kg lighter to lift onto a rack, train or stairs.
How you would ride it
Trek
Trek is one of the world's largest bike brands. Its Australian e-bike lineup spans the commuter-focused Verve+ and the performance Allant+, backed by a dense dealer network and strong after-sales support.
Compare similar e-bikes
Common questions
How much does the Trek Rail 9.9 XX1 AXS Gen 4 cost in Australia?
The Trek Rail 9.9 XX1 AXS Gen 4 is listed at $9,599.99 (Brand RRP; sale price shown on the brand's Australian site.). eBikeFinder checks pricing against manufacturer and distributor information, and prices can change with sales and stock. This price was last checked on 28 Sep 2026.
Is the Trek Rail 9.9 XX1 AXS Gen 4 road legal in Australia?
Yes. The Trek Rail 9.9 XX1 AXS Gen 4 is a 250W pedal-assist e-bike that stops assisting at 25 km/h, which meets the road-legal e-bike standard in every Australian state. Compliance is asserted by the brand rather than independently verified, so confirm the current spec with the seller.
What motor does the Trek Rail 9.9 XX1 AXS Gen 4 have?
The Trek Rail 9.9 XX1 AXS Gen 4 uses a Bosch Performance Line CX motor, in a mid-drive position, producing 85Nm of torque. Mid-drive motors climb hills better because they work through the bike's gears.
How much does the Trek Rail 9.9 XX1 AXS Gen 4 weigh?
The Trek Rail 9.9 XX1 AXS Gen 4 weighs about 23.6 kg. That matters if you need to lift it onto a car rack, carry it up stairs, or store it, since e-bikes are heavier than regular bikes because of the motor and battery.
Who sells and backs the Trek Rail 9.9 XX1 AXS Gen 4 in Australia?
The Trek range is distributed in Australia by Trek Bicycle Australia (Trek Concept Stores and authorised dealers). It comes with a Lifetime frame, 2 years motor and battery warranty. Buying from a brand with real Australian support matters most when something needs a warranty claim or a service.