DUOTTS C29-K 500W Electric Mountain Bike – When One Battery Was No Longer Enough

It was quiet at the Kruunuvuorenranta testing site.

The electric bike factory's test team had ridden dozens of electric bikes over the course of the week. Fast. Powerful. Lightweight. Aggressive.

But then something different arrived on the scene.

DUOTTS C29-K 500W electric mountain bike with a throttle.

Two batteries. Long range. 29-inch tires. And a look that immediately said one thing:

This bike is built for long rides.

Before the first test drive, one of the test drivers said:

“You could drive this all day without having to worry about the battery.”

He was right.

🔥 First ride impressions – more freedom than on a regular electric bike

As soon as the DUOTTS C29-K electric mountain bike started moving, I could feel the difference right away.

The 500W motor responded instantly. The half-twist throttle made takeoffs smooth and fast. And the dual-battery system gave me the feeling that I no longer had to plan my rides around the battery.

This isn't just any electric bike.

This is a long-range electric-assist mountain bike built for people who want to ride more—further and with less worry.

In the city, the bike rides smoothly and steadily.

But you only discover someone's true character when the asphalt ends.

🌲 On forest trails, the DUOTTS C29-K comes to life

Once the test team left the streets of Helsinki behind and headed for the sandy roads and forest trails, the real test began.

Roots. Gravel. Long uphill stretches.

But the DUOTTS C29-K electric mountain bike didn't become heavy or unstable.

The 29-inch tires rolled steadily over obstacles. The front suspension smoothed out the bumps. The Shimano 21-speed system kept the ride under control in all situations.

And when one of the riders decided to try going up the hill using only the throttle, the bike climbed without hesitation.

This off-road electric bike doesn't feel like it's struggling to handle the terrain.

It feels as if it were built there.

⚡ Dual battery = more driving, less charging

On many electric bikes, the battery starts to limit how far you can ride.

The DUOTTS C29-K electric mountain bike with a manual throttle does the opposite.

The 48V 15Ah + 22.5Ah dual-battery system offers an assisted range of up to 150–170 km.

That means:

longer commutes
longer weekend runs
fewer charging breaks
more freedom

This electric bike is designed for people who don't want to turn back too soon.

🧠 Smart, powerful, and ready for anything

The DUOTTS C29-K electric mountain bike combines performance and practicality in a way that few electric bikes can match.

Hydraulic disc brakes provide reliability in all weather conditions
The hand throttle enables fully electric driving
The LCD display shows everything you need to know at a glance
The phone's charging port stays connected throughout the entire trip

This isn't a bike that just looks good on paper.

This works in real life.

🌍 Built for the right purpose

Commuting around town? Perfect.
Long runs? Even better.
Forest trails and gravel roads? This is what it's made for.

The DUOTTS C29-K electric mountain bike combines:

mountain bike stability
the ease of an electric bike
long-range
and the freedom that comes with a hand throttle

This is a bike that makes you stop wondering how far you dare to go.

📊 Technical Specifications

🔹 Motor: 500W brushless motor
🔹 Torque: 65 Nm
🔹 Battery: 48V 15Ah + 22.5Ah dual battery
🔹 Range: up to 150–170 km with assistance
🔹 Electric range: about 60–80 km without pedaling
🔹 Top speed: 25 km/h (EU version)
🔹 Transmission: Shimano Tourney 21-speed
🔹 Brakes: Hydraulic disc brakes (160 mm)
🔹 Tires: Chaoyang 29” x 2.125”
🔹 Suspension: Front fork, 100 mm travel
🔹 Display: 2.4” HD LCD, Bluetooth-compatible
🔹 Charging time: 6–8 hours
🔹 Maximum load: 150 kg
🔹 Weight: about 32.5 kg
🔹 Rider height: 170–200 cm
🔹 Ascent angle: up to 30°
🔹 IP rating: IPX4
🔹 Throttle: Half-turn manual throttle
🔹 Additional features: Phone charging port, mud flaps, rear rack

🚀 Why do customers choose the DUOTTS C29-K?

Because this solves problems that ordinary electric bikes can't handle.

❌ “The battery runs out too quickly”
→ ✔️ The dual battery allows for really long drives
❌ “I don’t always want to pedal”
→ ✔️ The hand throttle gives you the freedom of all-electric riding
❌ “The bike doesn’t feel stable off-road”
→ ✔️ 29” tires + hydraulic brakes = controlled riding
❌ “I want one bike for everything”
→ ✔️ For the city, commuting, and off-road riding

⚠️ A truth you'll realize during the first week

When you ride this bike long enough, one thing changes:

You no longer wonder how long the journey is.

Because you know this bike can handle it.

🎯 The final vibe

When the test team returned to the test track in Kruunuvuorenranta, one of the drivers looked at the battery display and started laughing.

“We drove all day… and there’s still this much left.”

And that's exactly what the DUOTTS C29-K 500W electric mountain bike with a hand throttle is known for.

We also want to share useful information about the world of e-bikes. If you’d like to learn more about e-bikes, their benefits, and how they can be used, I recommend checking out the following resources:

Network of Cycling Communities– Up-to-date information on cycling in Finland.
Traffic Safety– Tips for Safe Electric Biking.
Fillari Magazine– Articles and reviews on cycling and e-bikes.
Motiva– Information on sustainable transportation solutions.

I hope you find some useful information in these links!

Best regards,
The SähköpyöräTehdas Team

🔹 Motor: 500W brushless motor
🔹 Torque: 65 Nm
🔹 Battery: 48V 15Ah + 22.5Ah dual battery
🔹 Range: up to 150–170 km with assistance
🔹 Electric range: about 60–80 km without pedaling
🔹 Top speed: 25 km/h (EU version)
🔹 Transmission: Shimano Tourney 21-speed
🔹 Brakes: Hydraulic disc brakes (160 mm)
🔹 Tires: Chaoyang 29” x 2.125”
🔹 Suspension: Front fork, 100 mm travel
🔹 Display: 2.4” HD LCD, Bluetooth-compatible
🔹 Charging time: 6–8 hours
🔹 Maximum load: 150 kg
🔹 Weight: about 32.5 kg
🔹 Rider height: 170–200 cm
🔹 Ascent angle: up to 30°
🔹 IP rating: IPX4
🔹 Throttle: Half-turn manual throttle
🔹 Additional features: Phone charging port, mud flaps, rear rack

Electric Bike Factory Warranty – We're Here to Support You

All electric bicycles come with a manufacturer's warranty that covers the most important parts as follows:

Frame: 10-year warranty against manufacturing defects.
Electric motor and its components: 2 years.
Battery: 2 years.
Other electrical components: 2 years.

The expert staff at Sähköpyörätehdas will support you throughout the entire warranty process, so you
don't have to worry. We'll handle everything for you directly with the manufacturer.

How we handle warranty issues on your behalf:

1. If a problem arises – Contact us at
If your electric bike develops a fault, contact Sähköpyörätehdas customer service immediately. You can
contact us by email, phone, or by filling out the warranty form on our website.
We ask that you describe the problem in detail and send any photos or
videos of the issue, along with your purchase information. This will allow us to assess the problem as quickly as possible.

2. Problem Assessment and Inspection
When you contact us, our expert will assess the situation and determine whether the problem is covered by the warranty
. If necessary, we’ll direct you to the nearest service center or arrange for your bike to be picked up
for a more detailed assessment. We’ll take care of everything for you—all you need to do is report
the problem and send your bike in for inspection.

3. Warranty Processing – We’ll handle communication with the manufacturer
Once we’ve confirmed that the defect is covered by the warranty, the Sähköpyörätehdas staff will handle
all communication with the manufacturer on your behalf. This includes submitting the necessary documents and information
as well as ordering any replacement parts. A warranty repair may involve replacing a part,
repairing the bike, or even delivering a new bike if the defect cannot be repaired.

4. Fast and Efficient Service
We ensure that the problem is fixed as quickly and professionally as possible. We’ll handle
all service-related arrangements for you, so you don’t have to worry about the details.
We’ll keep you updated throughout the process and notify you as soon as the service or repair is complete.

5. After a warranty repair – We’ll arrange for the return at
Once the problem has been fixed or the defective part has been replaced, we’ll notify you and arrange for the return or pickup of your bike at
We’ll make sure everything is in order before we return the bike to you at
.

6. Costs Covered by the Warranty
If the defect is covered by the warranty, repairs, part replacements, and return shipping are completely free of charge for you.
If the defect is not covered by the warranty, we will offer you a paid repair service and provide
a cost estimate before starting the work.

Sähköpyörätehdas Supporting You Every Step of the Way

We are committed to ensuring that your electric bike works flawlessly throughout the warranty period.

We'll handle all warranty matters with the manufacturer on your behalf, so you can focus on carefree
driving.

Sähköpyörätehdas's customer service is always ready to help you—just contact us at
and we'll take care of everything for you.

Maintenance and Assembly of Electric Bikes at the Electric Bike Factory

You can have your electric bike serviced either at our store in Helsinki or at service centers located elsewhere in Finland. You can easily find your nearest service location [here].

Assembling an Electric Bike

When you buy an e-bike from us, you can rest assured that we’ve made everything as easy as possible for you. Our e-bikes come 90% pre-assembled, which means you don’t have to worry about complicated assembly steps. For the final assembly, you’ll receive all the necessary tools and clear, step-by-step instructions to ensure your e-bike is ready to ride in just about 30 minutes.

However, if you need help at any stage, we’re here to assist you. You can contact us at any time, and we offer free video guidance via WhatsApp to ensure the assembly goes smoothly. If you’d still rather not assemble the e-bike yourself, you can also bring it to our store, and we’ll assemble it for you—this service is also designed to keep the process easy and hassle-free.

First Aid

The first service should be performed after about one month of riding or when the e-bike has been ridden 100–300 kilometers. This initial service includes a thorough wash of the e-bike, a comprehensive inspection of the electrical components, adjustments to the brakes and gears, tightening of the spokes, lubrication of the chains, and a general condition check. This service ensures that your e-bike is in top condition and ready for safe riding.

Annual Maintenance

Annual maintenance includes even more comprehensive procedures: battery testing, drivetrain cleaning, tire inflation and replacement, chain lubrication, and inspections and updates of all electrical systems. We recommend annual maintenance regardless of how often you use your e-bike, to ensure it remains in top technical condition and safe to ride all year round.

Prices for Maintenance and Repair Services

We keep our maintenance costs competitive. The price for an initial service starts at 90 EUR, and a comprehensive annual service costs 149 EUR (including 25.5% VAT).

If you'd like us to assemble your electric bike for you, you can bring it to our store; the assembly service costs 69 EUR.

Service and Assembly Appointment

You can schedule a service appointment or a pickup by calling our store directly or visiting our website.

If you can't make it to our store in Helsinki, you can take advantage of our service network, which covers all of Finland. [Click here] to see all of our service locations and their contact information.