SPEED15.5 Mph
RANGE70 Miles
MOTOR250W
BATTERY31.2Ah
CHARGING5 Hours
WEIGHT80 lbs
Adjustable Cycle Helmet£38.99
Front and Rear Light Set£44.99
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This Model Is Fully Compliant With UK Road Regulations
This bike is built to comply with UK Electrically Assisted Pedal Cycle (EAPC) regulations, meaning it can be used on public roads and cycle paths without registration, tax, or a licence. Motor assistance is limited to 250W and cuts off at 15.5 mph (25 km/h).
See UK LegislationThis one carries 1,498 Wh of battery. The maker quotes 70 mi; in mixed riding with some hills, expect nearer 53 mi. A full charge costs about £0.42. Across a year that is roughly £977.00 less than making the same journeys by car, so the bike pays for itself in about 13 months. Everything here is worked out from this bike's own specification. Estimates, not promises: the assumptions are printed underneath.
Range you can expect
| Low assist, flat roads | 70 mi |
|---|---|
| Mixed riding, some hills | 53 mi |
| Full assist, loaded or hilly | 39 mi |
| Riding time on a charge | 4 h 31 min |
What it costs to run
| A full charge | £0.42 |
|---|---|
| Every 100 miles | £0.60 |
| Electricity for a year | £13.00 |
| The same year by car | £990.00 |
| You keep | £977.00 |
| Pays for itself in | 13 months |
Worked out from the specification
| Battery energy | 1,498 Wh |
|---|---|
| Energy per mile | 21.4 Wh |
| Charger output | 6.2 A |
| Power to weight | 6.9 W/kg |
| You can carry | 265 lb |
Based on £0.245 per kWh, £0.45 per mile to run a small car, and 2,200 miles a year. Charging is costed at the socket, not at the battery.
Two batteries, 31.2Ah, on a bike that stays within the rules
The KOOLUX X9 Pro carries two batteries totalling 31.2Ah on a 48V system, with hydraulic brakes, at £1,039.
250W and 15.5 mph: it meets the EAPC rules, so there is no licence, no tax and no registration.
31.2Ah is a great deal of battery for a legal bike
More capacity than 96% of our catalogue, and it is the whole point of this machine.
- Seventy miles in our table, and KOOLUX claims up to 180 km
- Two packs mean a failure in one does not leave you walking
- You can charge only one when you know the ride is short
- A little over five hours for a full charge
Hydraulic brakes and a 7-speed transmission
Hydraulic rather than cable, on an 80 lb bike.
One finger is enough, they do not fade on a long descent, and they keep their bite in the wet. The shifter is a grip twist rather than a trigger, which some riders prefer and some do not: it is worth knowing before it arrives.
Twenty by four inch fat tyres
The small wheel keeps the centre of gravity low and the bike short; the wide tyre floats on sand, grass and soft ground.
Front suspension only, which KOOLUX states plainly. On a bike carrying this much battery weight low in the frame, that is a defensible place to stop.
An aluminium frame, and a 2026 model year
Aluminium will not rust in a damp shed, which is where an 80 lb bike ends up.
KOOLUX lists the model year as 2026 and the frame size as medium, unfolding to 162 × 69 × 116 cm. The box is 145 × 28 × 87 cm.
265 lbs of payload, and it is on the low side
Lower than 96% of our catalogue: you and everything on the bike, together.
That is the first line to check on this bike, because it is modest for a machine of this size. Subtract your own weight before you order.
Before the first ride, and who it is for
KOOLUX does not publish a torque figure for this model and that row stays empty below rather than being filled in on a guess.
- Fit the front wheel, the handlebars and the pedals, with two people
- Bed the hydraulic brakes in at walking pace
- Charge both batteries fully before the first long ride
- Run the tyres soft for grip, firmer for range
- Allow a little over five hours for the first charge
Buy it for the two batteries. Seventy miles on a legal 250W bike, with a second pack in reserve, is what separates it from everything else at this money.
- BRAND
- KOOLUX
- CATEGORY
- Fat Tire
- MOTOR POWER
- 250W
- RANGE
- 70 Miles
- SPEED
- 15.5 Mph
- BATTERY
- 31.2Ah
- WEIGHT
- 80 lbs
- CHARGING TIME
- 5 Hours
- BRAKE SYSTEM
- Hydraulic Disc Brake
- FRAME MATERIAL
- Aluminium Alloy
- MAXIMUM LOAD
- 265 lbs
- INPUT VOLTAGE
- 48V
- TIRE SIZE
- 20 inch
- TORQUE
- N/A
The Koolux X9 Pro Fat Tire Electric Bike states 250W, 70 Miles and 15.5 Mph, and below it is set against the DYU A1F Electric Folding Bike. Every figure the two disagree on is marked. Choose a different bike to compare it with whichever one you are also considering.
9 of 11 specifications differ. View DYU A1F Electric Folding Bike
- What is the benefit of the dual-battery system?
- The dual batteries provide longer riding range and consistent power for extended trips.
- Can the KOOLUX X9 Pro handle different terrains?
- Yes, its durable design and stable handling make it suitable for city roads and mixed terrain.
- Does the KOOLUX X9 Pro offer long-distance performance?
- Yes, the high-capacity 48V 31.2Ah dual-battery setup is designed for extended riding range.
- Is the KOOLUX X9 Pro suitable for daily commuting?
- Yes, it is designed for comfortable and efficient everyday riding.
- Are the electric bikes brand new?
- Yes. All electric bikes sold by BikTron are brand new, factory-sealed, and sourced directly from authorised manufacturers and official distributors.
- How do I choose the right electric bike for me?
- Pick a bike based on how you plan to ride. City bikes are great for commuting, folding bikes work well if you need compact storage, mountain bikes handle hills and mixed terrain, and cargo bikes are ideal for carrying shopping or loads. If you are not sure, our Bike Quiz can help.
- Are the batteries original and certified?
- Yes. Every electric bike battery is brand new and original from the manufacturer, with full safety certification and performance testing.
- Are the bikes tested before shipping?
- Yes. Each e-bike goes through a quality check before dispatch, covering electronics, brakes, motor response, and battery performance.
- Do electric bikes come with a warranty?
- Yes. All electric bikes from BikTron include a manufacturer warranty. Duration depends on the brand and model. Most bikes include a 12-month warranty as standard.
- How long does delivery take?
- Standard UK delivery usually takes 2 to 7 business days. Remote areas may take a little longer. You will receive a tracking link by email once your order is dispatched.
- Which payment methods do you accept?
- We accept Visa, Mastercard, PayPal, Apple Pay, Google Pay, and Klarna buy-now-pay-later. All payments are processed securely.
- Can I return my electric bike?
- Yes. You can ride the bike and still return it. Tell us within 30 days of delivery and we book the courier and collect it from your door. Contact us first and we will guide you through the process.
- Do the bikes need assembly?
- Most electric bikes arrive 85 to 90 per cent pre-assembled. You will usually need to attach the handlebars, pedals, and adjust the seat. A basic tool set is often included.
- Are BikTron electric bikes legal to ride in the UK?
- Yes. All bikes sold by BikTron that meet UK EAPC rules (250W motor, max 15.5 mph assisted speed, pedal-assisted only) are fully road-legal. You do not need a licence, tax, or insurance to ride them on public roads. Riders must be at least 14 years old.
- What about the electric scooters?
- Those are different, and the law treats them differently. A privately owned e-scooter cannot legally be ridden on a public road, pavement or cycle lane in the UK, whoever sold it. We sell ours for private land use only, with the landowner's permission, and every scooter product page says so. If you want something you can ride to work, choose an electric bike.
Secure checkout and fast UK delivery on every order.
- Free standard UK delivery on most bikes — 2 to 7 business days
- Express delivery may be available on request
- Full tracking included with every order
- Pay securely with Visa, Mastercard, PayPal, Apple Pay, Google Pay, or Klarna
- 0% finance available through Klarna at checkout
Before you order:
- Delivery is to UK mainland addresses — some remote areas may have a small surcharge
- Most bikes arrive 85–90% pre-assembled and include basic tools for setup
- If you are unsure about sizing or specs, contact us before you buy
Full details at Payment & Shipping.
Simple and fair terms so you can buy with confidence.
- 30-day return window — if the bike is not right for you, send it back
- Ride it. It needs to come back clean, undamaged and complete, with the charger, tools and manual
- A refund or replacement is issued after we receive and check the return
Please note:
- For a change of mind we book the collection and deduct its cost from your refund, and we tell you the amount before we book it
- If we sent the wrong item or it arrived faulty, we cover return shipping in full
- All bikes include a 12-month manufacturer warranty as standard
Full details at Returns & Refunds and Warranty.
Customer Reviews
5.00 out of 5
Based on 2 reviews
Absolute beast of a bike! KOOLUX X9 Pro is super fast, powerful dual battery lasts forever, feels solid and worth every penny!!
Excellent bike. I am very satisfied with it. It has good power, feels smooth on the road, and is very relaxing to ride. The quality feels solid, and it is comfortable for both daily use and longer rides. I would definitely recommend it 👍👍👍
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Helpful reading
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ReviewKOOLUX X9 Pro Review, Dual Battery Fat Tyre E-Bike
The KOOLUX X9 Pro's dual battery system and fat tyres are assessed against its published specifications and UK road laws. Read our full review.
Read guide →
ReviewKOOLUX X7 Cargo Electric Bike Review, Can It Replace Your Car?
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ReviewKOOLUX X10 Folding Electric Bike Review, Compact & Capable
The KOOLUX X10 folding electric bike promises a compact ride with surprising power. Our honest UK review covers real‑world range, folding ease, and whether it’s the right e‑bike for your commute.
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