First there was the forest. Next came the trail. And then there were mountain bikes. Hardtails for hammering. Full suspensions for crushing. Short travel whips. Long travel steeds. High-powered e-bikes. Now – there’s the Fuel EXe. Evolved to break the mould, bridge the gap and elevate your ride with quiet assist that all but disappears in the woods. The Fuel EXe is the culmination of your every desire on singletrack. It’s an e-mountain bike that empowers you to do more, without interrupting the way you experience nature. Just as a mountain bike should.
It’s your best trail ride ever, with extra Fuel in the tank.
Sometimes the beauty isn’t in what we see, but what we don’t. Nestled neatly behind the front chain ring, the naturally advanced harmonic pin ring transmission blends in effortlessly. Its petite package allows for a 39% smaller downtube than a traditional e-MTB, resulting in a ride that fits right in with traditional mountain bikes on the trail.
Less is more
When we’re on the trail and connecting with nature, we don’t want to hear more than the sound of our tyres on the dirt, the wind through the trees, and the hoots and shouts of our riding crew. Up until now, e-bikes have pulled us away from that experience with high-pitched motors that take us out of the element. The Fuel EXe is different. It’s not only quieter – it’s less annoying.
Tonality (sound perception)
When it comes to sound, decibels don’t tell the whole story. Sounds like a ripping current of a river or wind rustling through trees might measure in as quite loud, but they don’t distract us from the ride. That has everything to do with something called tonality.
Simply put, tonality is the measurement of how annoying and perceivable a sound is. It’s the difference between the crunch of leaves under your tyre, and a squeaking brake rotor.
Cadence and tonality
Tonality is measured in tonality units, or tu for short. Sounds that measure under 0.1 tu aren’t perceivable to the human ear, while sounds over 0.4 tu are grating and annoying.
The Fuel EXe’s motor is tuned for tone, measuring in under 0.2 tu – five times less perceivable than other light-assist bikes – so you can forgo the annoying whine of most e-bike motors to stay in the moment and connected with nature while you ride.
Data recorded in an anechoic chamber using a calibrated B&K 4966-h-041 microphone and Siemens SCADAS data acquisition unit with an acoustically-isolated Wahoo Kickr trainer set to 300 W total resistance and bikes in maximum-assist mode. Microphone was located 1 m laterally from the bottom bracket and 1.7 m off the floor (head height) and sampled at 51,200 Hz. Tonality calculated in Siemens Testlab Neo according to the ECMA-74:2019 standard.
Built like a trail bike. Rips like a trail bike.
The Fuel EXe is built with trail bike geometry that’s slack and capable out front with a 65-degree head tube angle.
A 77-degree seat tube angle keeps you perched for punchy climbs and long pedal fests up fire roads.
With a compact motor, the Fuel EXe’s chainstays are able to stay tight at just 440 mm, keeping the ride nimble and playful.
With 50 Nm of torque, the Fuel EXe has just the right amount of force for cranking up steep climbs without launching you forward with jerky propulsion. It finds the sweet spot between too much and too little for a ride that’s natural and smooth, but not overwhelmed.