AIO
Controller
U: 250Wh
U+: 360Wh
- ✓ Stronger, climb hills effortlessly
- ✓ Faster, save time
- ✓ Farther, push your limits
- ✓ Cost-efficient — save 1/3 of expense
You wonder.
Is it easy to install, tidy, and safe?
Discover VIER KIT now
Complete eBike conversion with Vier Kit U 2026
Vier Kit U: Turn Your Bike into an E-bike in 10 Minutes
- ✓ No need to buy a new bike
- ✓ Fits most bicycle types
- ✓ Easy installation
- ✓ Personalize your riding experience
Add POWER to go FASTER, and ride FARTHER
Buy nowPromotion timeline
- 01Early Bird
- 02Regular
- 03Shipping
- 04Complete
Empower Your Ride
Turn your familiar bicycle into a powerful eBike in 3 simple installation steps. Vier Kit U 2026 delivers a complete conversion — stronger, farther, and smarter than ever.
With a compact integrated design, intelligent AI PAS sensor, AIO Controller, and a suite of modern tech features, Vier Kit U is more than an upgrade — it's a new step for your green mobility journey.
Easy to install and compatible with most bikes — Empower Your Bike, so every pedal feels light and inspiring.
AIO
Hub Motor
Rated 250W
Peak 500W
AI Pedal Assist Sensor
Fits all bike types
10 Minutes
Installation
Installation
Easy
battery swap
battery swap
U: ~60km / charge
U+: ~80km / charge
U+: ~80km / charge
EU: 25 km/h, US: 32 km/h
Max: 40 km/h*
Max: 40 km/h*
Lightweight
Bluetooth
Personalized settings
Personalized settings
3 Installation Steps
Converting a bike to an eBike should be as easy as changing a wheel. No technicians, no complex tools — just 3 simple steps so anyone can upgrade their favorite bike.
With an integrated motor–battery–controller system, Vier Kit U delivers a fast, tidy, and precise install, saving you time while preserving the natural pedaling feel.
3 steps, 10 minutes, and your bike is ready to become an eBike.
Step 1: Replace with motor wheel
Remove the old wheel and mount the motor wheel on the fork.
Step 2: Mount the AIO Controller
Secure the battery-controller tube to the frame (downtube).
Step 3: Connect AI PAS
Attach the pedal-assist sensor, connect cables, and power on.
Fits all bike types
Easy home installation videos
Turn your familiar bicycle into a powerful eBike in 3 simple installation steps. Vier Kit U 2026 delivers a complete conversion — stronger, farther, and smarter than ever.
Multiple support modes
AI Pedal Assist System
Eco Mode
Comfortable daily riding and energy saving; balanced assist and personalized support.
AI Pedal Assist System
Slope Mode
Optimized assist for climbs; sensor algorithms adjust instantly to gradient.
AI Pedal Assist System
Sport Mode
Fast response, strong acceleration; ideal for training and high-intensity riding.
Free VIER App
Connect your bike to VIER APP to make every trip smarter and more enjoyable. The app helps you track rides, adjust assist levels, manage battery, and customize riding modes.
From gentle Eco to flexible Tour and powerful Sport — control the ride with one tap. The intuitive dashboard shows distance, speed, energy use, and performance so you understand your bike better.
VIER APP – Ride Smart, Live Green.
Personalize, connect, and enjoy cycling with smart tech from VierCycle.
Extended Features
Fast charging in just 3 hours keeps you on the go, with an integrated USB port for mobile devices and a flashlight.
Battery lock secures the unit and makes the pack easy to remove.
"Đạp nhanh hơn - Đi xa hơn."
Đặt hàng ngay
Minimal design
Tidy cable routing
Fewer cables — cleaner and sleeker bike aesthetics.
Meets protection
and safety standards
Grade A
Highest quality battery cells
21700 battery cells, brand new, durable and safe.
IP65 Water-resistant,
Protection from water and dust
Ready for outdoor use.
Safe battery charging
Charging standards for EU and US export markets.
Tilt Detection
Sensor detects if tilt exceeds 45°, cutting power to maximize safety.
Compliance & Protection
The Vier Kit meets and exceeds global standards for safety, quality, and environmental compliance.
CE
European Conformity
RoHS
Hazardous Substances
IP67
Water & Dust Resistance
UL
Battery Safety Standard
ISO 9001:2015
Manufacturing Quality
Healthy exercise
Protect your health
VIER KIT doesn't replace your bike — it helps make you stronger.
With an intelligent pedal assist system, you remain in control of the ride — every pedal is yours, but VIER KIT provides just enough assist to make trips smoother and easier.
The product helps protect knees, reduce fatigue, and maintain a steady heart rate so you can ride farther, climb higher, and enjoy more trips without exhaustion.
It doesn't mean less exercise — it means riding longer, stronger, and healthier.
"Đạp nhanh hơn - Đi xa hơn."
Đặt hàng ngayAccessory upgrades
Enhance your ride with plug-and-play accessories.
Technical Specifications
Motor weight
2.7 kg
Battery weight
2.0 kg (U) / 2.5 kg (U+)
Motor power
250 W continuous / 500 W peak
Range
60 km (U) / 80 km (U+)
Top speed
25 km/h (EU), 32 km/h (US)
Battery
250Wh (U) / 360Wh (U+)
Charging time
Standard charge: 3 hours / Fast charge: 2 hours
Assist modes
Eco / Tour / Sport / Slope Mode
Connectivity
Bluetooth
Water resistance
IP65 Motor / IP66 Controller
App
iOS & Android
Video Reviews
Watch people's feedback on Vier Kit.
Pre-order Program
Information about the campaign timeline.
Now-
Phase 1. Early Bird
- Discounts up to 35% *
- Warranty package 24 months.
- The first 100 customers receive custom cable design for free
-
Phase 2. Regular
Early Bird promotion ends. Regular orders open.
- Discounts up to 15% *
- Warranty 12 months.
- 1-for-1 replacement within 6 months.
-
Fulfillment will follow order sequence.
-
Pre-order campaign ends.
*When paying 100% of the order
"Đạp nhanh hơn - Đi xa hơn."
Đặt hàng ngayGo Global with Vier Kit
VierCycle is a green mobility technology company in Vietnam, providing conversion solutions to turn simple vehicles (bikes, rickshaws, wheelchairs...) into full electric mobility.
Our goal is to convert 1,000,000 vehicles around the world.
Meet the Team
VierCycle brings internationally compliant products to everyone.
Lộc Phạm
CTO - Product Firmware / Software
Ho Chi Minh City Univ. of Technology 2010
Tiến Trần
CEO - Business / Sales
Ho Chi Minh City Univ. of Technology 2008
Tiên Phạm
Product Lead
Ho Chi Minh City Univ. of Technology 2016
What we've built
From the first prototype to production: lighter, stronger, install in under 10 minutes.
Awards & Recognition
Green Innovation Contest 2024
TOP 5.
Smart City 2024
TOP 3.
Startup Wheel 2024
TOP 50.