A ready-to-race hard enduro two-stroke with throttle-body injection, built with feedback from 2024 Erzbergrodeo winner Manuel Lettenbichler.
Background
KTM builds the 300 EXC HARDENDURO for the world's toughest extreme enduro events, using input from Manuel Lettenbichler, winner of the 2024 Erzbergrodeo.
Design
It starts with the 300 EXC and adds closed-cartridge WP XACT 48 mm forks (300 mm travel), a WP XPLOR PDS shock (310 mm), extra protection and grab straps, the equipment hard-enduro racers usually fit themselves.
Engine
The 293.15cc two-stroke single uses Keihin throttle-body injection with a 39 mm throttle body, so riders don't need to rejet a carburettor for altitude or temperature. It has electric start and a six-speed gearbox.
On the trail
At 106.1 kg without fuel and with 347 mm of ground clearance, it is built for rocks, logs and steep climbs. The 963 mm seat height is typical for the class.
Market context
KTM pitches it as a bike that can go straight from the team van to the start line. Buyers get race-team specification without a long list of aftermarket parts.
Why hard enduro needs its own bike
Hard enduro is the most extreme branch of off-road racing: events like the Erzbergrodeo send riders up rock faces, through river beds and over logs where a standard enduro bike struggles. Riders in this class have traditionally modified their bikes heavily. The HARDENDURO is KTM's answer, with that work done at the factory.
The Lettenbichler connection
KTM developed the bike with feedback from Manuel Lettenbichler, the 2024 Erzbergrodeo winner and one of the most successful hard-enduro riders of his generation. His input shows in the choice of suspension, protection and ergonomics.
Two-stroke with fuel injection
The 293.15cc two-stroke single uses Keihin throttle-body injection through a 39 mm throttle body. Fuel injection matters in hard enduro because events often climb steeply and run through cold mornings and hot afternoons. An injected two-stroke adjusts its fuelling automatically, where a carburettor would need rejetting. The engine has electric start and a six-speed gearbox.
Suspension and protection
The WP XACT 48 mm closed-cartridge fork has 300 mm of travel, and the WP XPLOR PDS rear shock has 310 mm. KTM adds extra protection for the engine and frame, plus grab straps that help riders and helpers drag the bike over obstacles, a common sight at hard-enduro events.
Dimensions
The bike weighs 106.1 kg without fuel and has a tank of about 9 litres. Seat height is 963 mm and ground clearance is 347 mm, a figure that matters most when riding over rocks and logs.
Market
KTM sells the HARDENDURO as a ready-to-race machine for serious amateurs and professionals. Buying it saves the cost and time of fitting many of the same parts aftermarket.
The rivals
Hard-enduro riders also look at two-strokes from Husqvarna and GasGas, KTM's sister brands, and at specialist makers such as Beta and Sherco. Many riders still build their own hard-enduro bikes from a standard enduro model, so the HARDENDURO also competes with the aftermarket.
Who it suits
The bike is aimed at experienced riders who enter, or plan to enter, extreme enduro events, and at riders who spend most of their time on very technical terrain. For mixed trail riding a standard 300 EXC is likely to be a better all-rounder.
Our judging notes
The panel valued the fact that this is a complete, race-ready package designed with a current champion rather than a list of options. Fuel injection, specialist suspension and real protection from the factory made it our 2025 Off-road Petrol winner.
Two-stroke heritage
KTM has built off-road two-strokes for decades, and its 300 has long been one of the most popular engines in enduro and extreme enduro. Fuel injection arrived on KTM's off-road two-strokes in recent years, and the 2025 HARDENDURO uses the latest throttle-body system.
Reading the numbers
The 106.1 kg dry weight makes the bike easier to lift over obstacles. The 347 mm ground clearance helps it clear logs and rocks without grounding the frame. With about 9 litres of fuel the bike carries enough for typical hard-enduro race loops, while keeping weight down.
Who it suits
The HARDENDURO suits experienced riders who tackle rock gardens, steep climbs and log crossings, and who value low weight and smooth delivery over outright top speed.
Specification breakdown
- Engine: 293.15cc single-cylinder two-stroke, Keihin TBI (39 mm throttle body).
- Gearbox: 6-speed.
- Starter: Electric.
- Weight: 106.1 kg without fuel.
- Fuel: Approx. 9 L.
- Suspension: WP XACT 48 mm fork (300 mm travel); WP XPLOR PDS shock (310 mm).
- Seat height: 963 mm.
- Ground clearance: 347 mm.
- Price: Not stated by KTM here; see local dealer.
Why it won
The 2025 HARDENDURO takes the 300 EXC and adds closed-cartridge WP XACT forks, extra-tough protection and grab straps. KTM designed it to go straight from the team van to the start line of the world's hardest enduro events.
Watch
Video: Take on the impossible with the 2025 KTM 300 EXC HARDENDURO – KTM