DYU C9

PRICE

• DYU C9 €899.00
  View Offer

Here’s a question for anyone who’s ever considered a folding e-bike: how far is far enough?

Most folding e-bikes give you 40–60 km of real-world range. That’s fine for a commute, maybe a trip to the store and back. But it’s not enough to truly replace a car. It’s not enough for the weekend adventure that starts at your doorstep and doesn’t end until you’ve seen the other side of the city. It’s not enough to make you forget about range anxiety entirely.

The DYU C9 was built to change that calculation. With a 48V 15.6Ah battery packed into a folding 20-inch fat-tire frame, it promises up to 150 km of pedal-assist range—enough to turn a folding e-bike from a commuter convenience into a genuine car replacement.

After digging through real-world tests, expert reviews, and owner experiences, here’s the unvarnished truth about whether the C9 delivers on that promise—and who it’s actually for.

What Makes the C9 Different?

The folding e-bike market is crowded with bikes that prioritize fold over function. They fold small, but they ride small too—anemic motors, tiny batteries, and ride quality that reminds you with every bump that you’re on a compromised machine.

The C9 takes the opposite approach. It’s a 20-inch fat-tire folding e-bike that doesn’t apologize for being substantial. With a 748.8Wh battery (48V, 15.6Ah) and a motor that ranges from 250W (EU) to 750W or even 1000W peak (US/international), it’s built for riders who want real range, real power, and real versatility—all in a package that folds.

Torque and Climbing: The 40 Nm Workhorse

The C9 produces approximately 40 Nm of torque. That’s not class-leading—the ENGWE O20 Boost offers 75 Nm—but it’s more than enough for urban riding. Real-world tests show the C9 climbing inclines up to 20% using only the throttle. One reviewer noted that “this bike made my hilly neighborhood a breeze”.

Throttle Performance: Instant Gratification

Multiple reviewers highlight the throttle’s instant response and strong acceleration. The thumb throttle sits naturally near the left grip, allowing you to engage the motor without pedaling—perfect for walking the bike through pedestrian areas or getting a quick start from traffic lights.

Pedal Assist: The Half-Second Delay

The pedal assist system uses a speed sensor rather than a torque sensor. There’s a noticeable delay of about half a second before the motor engages after you start pedaling. It’s not a dealbreaker—one reviewer called it “noticeable but not a dealbreaker”—but it’s worth knowing if you’re used to the instant response of a torque-sensor system.

Range: Real-World vs. Claimed

The claimed range is up to 150 km (93 miles) in pedal-assist mode. But as with any e-bike, real-world results vary:

The 130–140 km figure from Volt Bike is remarkable—and suggests that with conservative assist settings and flat terrain, the C9 genuinely delivers on its long-range promise. The more conservative 50–70 km figures likely reflect heavier throttle use and hillier terrain.

One thing is clear: the C9 has DYU’s longest folding-bike range. As one reviewer put it, “this lasts several days of running errands”.

Charging Time

Full charge takes approximately 7–8 hours. That’s not fast-charging territory, but it’s perfectly adequate for overnight top-ups between rides.

Hydraulic Disc Brakes: The Standout Feature

The C9 is equipped with hydraulic disc brakes and 180mm rotors—a feature that multiple reviewers highlight as a standout at this price point. Unlike mechanical disc brakes that require frequent adjustment, hydraulic brakes provide firm, consistent stopping power.

Reviewers note this is “a notable upgrade compared to cheaper mechanical braking systems”, giving riders “confidence when navigating traffic or riding at higher speeds”.

Lighting and Visibility

The C9 comes with fenders, a headlight, and a taillight with brake activation. The rear brake light is built into the rack—a thoughtful integration that improves visibility when stopping.

Safety Switch

A small safety switch prevents the bike from accidentally powering on while folded or being transported—a thoughtful touch that “adds polish to the design”.

Competitive Comparison: How Does the DYU C9 Stack Up?

Summary

The DYU C9 is not the lightest folding e-bike. It’s not the most refined. It doesn’t have the most sophisticated torque-sensor system. But it does one thing that very few folding e-bikes can do: it gives you car-replacing range in a foldable package.

With 150 km of claimed range and real-world figures of 130–140 km in city conditions, the C9 turns a folding e-bike from a commuter convenience into a genuine transportation alternative. You can run errands all week without charging. You can take the long way home. You can replace short car trips—and that’s exactly what Volt Bike’s reviewer did.

The trade-off is weight. At 30 kg, the C9 is not a bike you’ll casually carry up stairs. But if you’re rolling it—through garages, into trunks, onto trains—the weight is a fair price to pay for the range, the fat-tire stability, and the premium features that come standard.

At €899, the C9 offers exceptional value. It’s not the best folding e-bike money can buy—but it might be the best long-range folding e-bike for the money you can buy.

If your commute involves city streets, tight storage, and the desire to never worry about range again, the DYU C9 isn’t just a bike. It’s a freedom machine.

SPECS