Full-Suspension 20-Inch Fat-Tire Electric Bike
HKM-7186131 Electric Fat Tire Bike
The HKM-7186131 is built around three numbers that rarely appear together: a 912 Wh battery, a charge time of roughly three hours, and suspension at both ends. A 48 V 1000 W rear hub motor drives 20 x 4.0 in fat tires to a configurable top speed between 18.6 and 31 mph, and the 19 Ah pack tucked into the down tube carries the bike past 37 mi (60 km) on a charge. Hydraulic disc brakes, a 7-speed drivetrain, and an aluminum alloy frame round out a bike that treats a rough back road the same way it treats a smooth one.
1000 W Rear Hub Motor48 V 19 Ah / 912 Wh Pack18.6-31 mph Configurable37+ mi Range20 x 4.0 in Fat TiresFront and Rear SuspensionHydraulic Disc Brakes3-Hour Fast Charge
Motor
1000 W
48 V brushless rear hub
Battery
48 V 19 Ah
912 Wh in the down tube
Top Speed
18.6-31 mph
30-50 km/h, configurable
Range
37+ mi
Over 60 km per charge
Tires
20 x 4.0 in
Fat tread, road and trail
Charge Time
~3 hr
Just over three hours from empty
Overview
Charge time is the specification riders notice most after the first month of ownership, and it is the one most bikes in this class quietly get wrong. A 912 Wh pack behind a typical 2 A charger is an overnight job. The HKM-7186131 fills the same pack in just over three hours, which changes what the bike can do in a day: ride out in the morning, charge over lunch, and ride back with a full pack rather than rationing the return trip.
Power comes from a 48 V 1000 W brushless rear hub motor. Top speed is configurable across a 30-50 km/h band (18.6-31 mph), which matters because that range straddles the legal line in most places. Set low, the bike behaves like a fast commuter and stretches its range; set high, it holds 30 mph on open road. Understand which setting is lawful where you ride before you choose, because the classification consequences are real.
The 48 V 19 Ah pack stores 912 Wh inside the down tube rather than on a rear rack. Placing the heaviest single component low and between the axles has a measurable effect on how the bike corners and how it behaves on loose ground - the bike stays settled instead of feeling like it is being steered by a weight at the back. Stated range is over 60 km (37 mi) per charge, and the pack is removable for indoor charging.
Suspension at both ends is what separates this from most 20 in fat tire bikes. The front fork handles the sharp hits before they reach your wrists, and the rear shock keeps the driven wheel in contact with broken surfaces instead of skipping over them - which is a traction issue as much as a comfort one on a 1000 W bike. Braking is hydraulic disc at both ends, correctly matched to a machine that can reach 31 mph.
Key Features
48 V 1000 W Brushless Rear Hub Motor
The motor is laced directly into the rear wheel, so there is no secondary chain, belt, or gearbox between drive and ground. 1000 W at 48 V gives strong acceleration from a standstill and enough reserve to hold speed on a moderate climb with a rider and cargo aboard. Drive losses stay low and routine maintenance amounts to keeping the axle nuts torqued.
48 V 19 Ah Down-Tube Pack (912 Wh) with 3-Hour Charging
The pack sits inside the down tube behind a locking cover and lifts out with a key for indoor charging. 912 Wh supports over 37 mi (60 km) per charge, and the supplied charger refills it in just over three hours - roughly half the time a conventional 2 A charger would take on a pack this size. The management system guards against overcharge, over-discharge, and temperature extremes.
Front and Rear Suspension
A suspension fork at the front and a rear shock give the bike real travel at both ends. Comfort is the obvious benefit; traction is the less obvious one. Keeping the driven rear wheel pressed into a broken surface rather than bouncing clear of it is what lets 1000 W actually reach the ground on gravel, root, and washboard.
Hydraulic Disc Brakes, Front and Rear
Sealed hydraulic lines actuate both calipers, giving light lever effort, fine modulation, and consistent performance when the rotors heat up on a long descent. There are no cables to stretch or corrode, and the system self-adjusts as the pads wear. Both levers cut motor power the moment they move.
7-Speed Derailleur Drivetrain
Seven gears keep pedalling useful across the whole speed range. On a bike that can reach 31 mph this matters more than on a slow one: without enough top gear you spin out and stop contributing, and with it you can add power at cruising speed and meaningfully extend the range on a long ride.
20 x 4.0 in Fat Tires
Wide casings on 20 in rims put a large contact patch on the ground - grip on gravel, wet tarmac, forest track, and packed snow, plus strong resistance to pinch flats. The 20 in diameter keeps standover height and the centre of mass low, which is a large part of why the bike feels planted at speed.
LCD Display and Integrated Lighting
A backlit LCD reports speed, battery state, assist level, trip distance, and odometer at a glance. Lighting is powered from the main pack, so there are no accessory batteries to keep charged and no beam that fades toward the end of an evening ride.
Aluminum Alloy Frame with Integrated Cabling
The frame is aluminum alloy, which keeps corrosion at bay on a bike that will see wet roads, and the battery and cabling are routed inside the tubes rather than strapped to them. The result is fewer exposed connectors to corrode and a bike that is straightforward to clean after a muddy ride.
Full Specifications
Model
HKM-7186131 | Electric Fat Tire Bike
Frame Material
Aluminum alloy, internally routed cabling
Motor
1000 W brushless rear hub motor
System Voltage
48 V DC
Battery
48 V 19 Ah lithium-ion (912 Wh), down-tube integrated, removable and lockable
Charger
Fast smart charger, 100-240 V input
Charging Time
Just over 3 hours from empty
Battery Cycle Life
Approximately 800 charge cycles to 80 percent capacity
Top Speed
18.6-31 mph (30-50 km/h), configurable
Range Per Charge
Over 37 mi (60 km), varies with terrain, rider weight, and assist level
Climbing Grade
Up to approximately 20 percent incline
Speed Settings
Controller-configurable top speed across the 30-50 km/h band
Drivetrain
7-speed rear derailleur with index shifter
Brakes
Hydraulic disc, front and rear, with motor cut-off levers
Suspension
Front suspension fork and rear shock
Tires
20 x 4.0 in fat tires, mixed road and trail tread
Wheels
20 in alloy rims, stainless spokes
Saddle
Padded saddle with a moderately upright riding position
Display
Backlit LCD: speed, battery level, assist level, trip distance, odometer
Throttle and Assist
Twist throttle plus 5 levels of pedal assist and zero assist
Lighting
LED headlight and tail-light powered by the main battery
Payload Capacity
Approximately 330 lb (150 kg) rider plus cargo
Battery Placement
Housed inside the down tube, key-locked, lifts out for indoor charging
Recommended Rider Height
5 ft 3 in to 6 ft 4 in (160-193 cm)
Certifications
CE, RoHS; battery cells UN38.3 tested
Battery, Range, and Charging
The 48 V 19 Ah pack stores 912 Wh - roughly double what a typical city e-bike carries, and enough to put the stated range past 60 km (37 mi) even with a 1000 W motor drawing on it. The pack lives inside the down tube, which keeps the mass low and centred and leaves the frame lines clean. It unlocks with a key and lifts out for charging away from the bike.
The charging figure is the one worth planning around. Just over three hours from fully empty means the pack can be refilled inside a working day rather than only overnight, which effectively doubles the distance the bike can cover between the time you leave and the time you get home. Real range still depends on the usual variables: how much you pedal, rider and cargo weight, tire pressure, terrain, and which top-speed setting the controller is running. Cold below 40 F (4 C) temporarily costs 10-20 percent of usable capacity and returns as the pack warms.
Tip: Fast charging is convenient but generates more heat than slow charging. Charge indoors at room temperature on a hard, non-flammable surface, and let the pack cool for 20-30 minutes after a hard ride before plugging it in.
For storage longer than a month, leave the pack at 30-70 percent charge and top it up every 4-6 weeks. Charging in place through the frame-side port works as well as charging off the bike - the port sits behind a sealed cover on the drive side.
Daily Use & Care
- Set tire pressure for the surface: higher for efficient tarmac riding, lower for gravel, trail, or snow where a larger contact patch buys grip.
- Rinse and dry the frame, rims, and drivetrain after riding on salted or muddy roads, and avoid pointing a pressure washer at the hub, shock, or fork seals.
- Re-torque the axle nuts, stem bolts, and rear shock hardware weekly. Hub-motor torque works fasteners loose faster than a conventional bicycle drivetrain.
- Clean and re-lubricate the chain every 100-150 mi or after any wet or dusty ride, and check derailleur indexing at the same time.
- Inspect brake pad thickness monthly, and plan on a hydraulic bleed every 12-18 months to keep lever feel consistent.
- Wipe the fork stanchions and the rear shock shaft after dusty rides so grit is not dragged past the seals.
- Charge indoors at room temperature, on a non-flammable surface, and unplug once the charger indicator turns green.
What's in the Box
- 1 x HKM-7186131 electric fat tire bike, approximately 85 percent pre-assembled
- 1 x 48 V 19 Ah removable down-tube lithium battery pack
- 1 x Fast smart charger with 100-240 V input
- 2 x Battery keys
- 1 x Toolkit with hex wrenches and pedal spanner
- 1 x Pair of pedals
- 1 x Kickstand (pre-installed)
- 1 x Illustrated user manual and assembly guide
Frequently Asked Questions
How fast does it actually charge?+
Just over three hours from fully empty with the supplied charger. A pack this size on a conventional 2 A charger would take roughly twice that. Partial top-ups take proportionally less time, and there is no benefit to running the pack down before recharging.
What does the 18.6-31 mph speed range mean?+
The controller can be configured to different top speeds within the 30-50 km/h band. That band spans the legal boundary in most jurisdictions, so which setting is appropriate depends entirely on where you ride. Confirm your local rules before selecting a setting, and contact support if you need the configuration changed.
What range should I plan for?+
Over 37 mi (60 km) is the stated figure under moderate assist on reasonable surfaces. Sustained riding at the top of the speed range with no pedal input will land well below that; light assist on level ground with real pedal effort will beat it. Rider weight, tire pressure, headwind, and temperature all move the number.
Why does a fat-tire bike need rear suspension?+
Comfort is only half of it. A rear shock keeps the driven wheel in contact with broken ground instead of letting it skip clear, and a wheel that is off the surface is not transmitting any of the 1000 W. On gravel, roots, and washboard the traction difference is as noticeable as the comfort one.
How much assembly is required out of the box?+
The bike arrives approximately 85 percent assembled. You fit the front wheel, align and bolt the handlebar, install the pedals and saddle, and check brake and derailleur alignment. Budget 30-45 minutes with the supplied tools, or have a shop finish and torque the build.
Is a licence or registration required?+
It depends on the speed setting and your local rules. At the top of the range, a 1000 W motor with a 31 mph top speed exceeds the common three-class US e-bike framework and may be treated as a moped or motor-driven cycle. Check your state DMV and local ordinances before riding on public roads or paths.
Can the battery be removed for indoor charging?+
Yes. It unlocks with the supplied key and lifts out of the down tube in seconds, so you can charge indoors while the bike stays locked outside. Charging in place through the frame port works equally well.
Can I pedal it if the battery is flat?+
Yes. The 7-speed derailleur drivetrain is independent of the motor, so the bike rides as a bicycle with the system off. It is heavier than an unpowered bike, so treat unassisted pedalling as a way home rather than a riding mode.
Service & Policies
Free Shipping on All Orders
Every order ships free. Handling Time: 0-1 business days (Monday to Friday). Transit Time: 2-5 business days (Monday to Friday). A tracking number is emailed as soon as the parcel leaves our warehouse.
180 Days Purchase Protection
Your purchase is protected for 180 days from the delivery date against manufacturing defects and damage in transit. If something arrives wrong, we make it right.
30 Days Money-Back Guarantee
Not completely satisfied? Request a return within 30 days of delivery for a full refund. We keep the process simple and hassle-free.
24 Months Warranty Service
The product is covered by a 24-month warranty from the delivery date against manufacturing defects. Coverage includes parts and labor; normal-wear items are excluded.
CERoHSUN38.3 Battery912 Wh PackHydraulic BrakesFull Suspension3-Hour Fast Charge
Why Choose the HKM-7186131
A Three-Hour Charge Changes the Day
Range specifications describe one direction of travel. Charge time describes whether you can go there and back. Refilling 912 Wh in just over three hours means a lunch stop is a full recharge, not a partial one - which is a different kind of freedom from simply having a bigger battery.
Suspension Where the Power Goes Down
Front suspension protects the rider. Rear suspension protects the traction. On a rear-drive bike with 1000 W available, keeping the driven wheel loaded on rough ground is what turns motor output into forward motion rather than wheelspin.
Set the Bike to Your Rules
A configurable top speed across the 30-50 km/h band means one machine can be a legal pedal-assist commuter in one place and a faster private-land bike in another. It also gives a direct lever on range - lowering the ceiling meaningfully extends how far a charge goes.
Direct Hub Drive, Few Wear Items
No mid-drive gearbox, no secondary chain, no belt. The motor is part of the rear wheel, which means fewer things to service in the drive path and a ride quiet enough that tire noise dominates at cruising speed.
Mass Low, Mass Centred
Putting 912 Wh inside the down tube instead of on a rear rack lowers the centre of gravity and moves it between the axles. In corners, on gravel, and when manoeuvring at walking pace the bike feels noticeably more settled for it.
Built for Real Weather
Internally routed cabling, sealed hydraulic brake lines that cannot corrode in road film, a covered charge port, and an aluminum frame that will not rust. This is a bike specified to be ridden through a normal week rather than stored for good days.
Controls & Indicators
Power Button
On the battery pack; hold to switch the system on and off
Mode Buttons
Up and down buttons cycle through 5 pedal-assist levels plus zero assist
Twist Throttle
Right-hand grip; proportional response, independent of the assist level
Speedometer
Live speed on the backlit LCD, switchable between mph and km/h
Battery Gauge
Segmented charge indicator with percentage readout
Light Switch
Long-press the up button to toggle the LED headlight and tail-light
Shifter
Right-hand index shifter for the 7-speed rear derailleur
Pre-Ride Safety Checklist
- Check tire pressure and set it for the surface you plan to ride; fat tires lose pressure slowly but noticeably across a week.
- Squeeze both brake levers. They should firm up well before reaching the grip, with no sponginess suggesting air in the hydraulic line.
- Confirm the battery is locked into the down tube and the display shows the state of charge you expect.
- Spin both wheels and check that the rims run true and nothing rubs the pads, the fork lowers, or the frame.
- Verify the axle nuts, stem bolts, and rear shock hardware are tight, and rock the bike with the front brake applied to check for headset play.
- Shift through all 7 gears at low speed and confirm the chain moves cleanly without skipping.
- Test the throttle at walking pace in a clear area before riding in traffic, and confirm which top-speed setting the bike is currently running.
- Wear a helmet rated for the speeds this bike reaches, and switch on the lights if you will be riding near dusk.
Quick Troubleshooting
The motor does not engage when I twist the throttle.+
Confirm the display is on and shows charge, the battery is locked into the down tube, and both brake levers are fully released - the cut-off sensors disable drive while a lever is pulled. Check the assist level is above zero. If an error code appears, note it and contact support.
The bike stops accelerating well below 31 mph.+
Check which top-speed setting the controller is configured to; the bike can be set anywhere in the 30-50 km/h band and a lower setting is not a fault. Also check tire pressure and battery state of charge, both of which reduce available speed as they drop.
Charging takes much longer than three hours.+
Confirm you are using the supplied fast charger rather than a generic replacement, and that the pack is not being charged in a cold garage - lithium packs charge more slowly when cold, and some chargers deliberately reduce current below a temperature threshold. If neither applies, contact support.
The brakes feel spongy at the lever.+
Sponginess in a hydraulic system means air in the line, a fluid leak, or badly worn pads. Stop riding and have the system inspected and bled. Do not continue riding a 31 mph bike on compromised brakes.
The rear shock bottoms out or feels harsh.+
Preload is likely set wrong for your weight. Increase it if the shock bottoms out on ordinary bumps, back it off if the ride is harsh and the shock is barely using its travel. Change one thing at a time and re-ride the same stretch of road to judge the effect.
The display shows an error code and the bike will not move.+
Switch the system off, wait 30 seconds, and switch it back on. If the code returns, record the exact code and the conditions that produced it, then contact support - codes map to specific faults in the controller, motor, throttle, or battery circuits.
Certifications & Standards
The HKM-7186131 is produced in a facility operating under an ISO 9001 quality management system. The lithium cells and the assembled 48 V pack carry the test documentation normally required for lithium-ion transport and sale.
- CE - European Conformity marking covering the electrical assembly.
- RoHS - Restriction of Hazardous Substances compliance for the electronics.
- UN38.3 - Battery transport safety testing, required for lithium-ion shipping by air, sea, and road.
- MSDS - Material Safety Data Sheet available for the battery pack on request.
- ISO 9001 - Quality management system certification held by the manufacturing facility.
Important Safety Notes
At the top of its configurable range this bike reaches 31 mph (50 km/h) on a 1000 W motor, which is far beyond conventional bicycle speeds. Read the manual before the first ride, start at a low assist level, and practise throttle and brake control in an open, traffic-free area until the response feels predictable.
- Wear a helmet on every ride. At 31 mph a standard bicycle helmet is the minimum; many riders choose a certified motorcycle or downhill helmet at these speeds.
- Do not exceed the payload capacity of approximately 330 lb (150 kg), which includes the rider and all cargo.
- Confirm which top-speed setting is lawful where you ride. A 1000 W motor at 31 mph may place this vehicle outside standard e-bike classifications in your area.
- Bed in the brake pads with 10-15 progressive stops from moderate speed during the first rides before using the full speed range.
- Do not ride through water deep enough to reach the hub motor or the battery compartment, and do not pressure-wash the bike.
- Charge only with the supplied charger, indoors, at room temperature, on a non-flammable surface, and do not leave a charging pack unattended overnight.
- Do not open, puncture, or modify the battery pack. Damaged lithium cells can vent and ignite.
- Reduce speed substantially on gravel, wet surfaces, and downhill grades; fat tires add grip but do not remove the risk of losing traction.
HKM-7186131 · 1000 W brushless rear hub motor · 48 V 19 Ah lithium (912 Wh) integrated in the down tube · 18.6-31 mph (30-50 km/h) configurable top speed · over 37 mi (60 km) range · just over 3 hour charge from empty · 20 x 4.0 in fat tires · aluminum alloy frame · front and rear suspension · hydraulic disc brakes front and rear · 7-speed derailleur. Specifications are provided for reference; actual performance varies with rider weight, terrain, tire pressure, temperature, and riding style. Range figures are measured under moderate pedal assist on level ground. This page describes the product only and is not legal advice regarding vehicle classification - confirm local regulations before riding on public roads.
Nationwide Service Network & Support
With over 3,000 authorized service centers across the United States, we ensure comprehensive after-sales support for your vehicle, giving you complete peace of mind.
We understand that maintenance needs may arise. When you purchase from us, you gain access to our unparalleled service ecosystem designed for maximum convenience and reliability.
1. DIY Repair & Parts Replacement:
For minor repairs or part replacements that can be handled personally, we provide cost-price genuine parts during the warranty period. Each order is accompanied by clear, step-by-step video tutorials to guide you through the self-repair process seamlessly.
2. Professional Servicing:
For issues requiring expert attention, simply contact our support team. We will locate the nearest authorized service center based on your order and location details. You only need to bring your vehicle to the designated center. Once servicing is complete, we will notify you for pickup. All repairs are free during the warranty period; afterward, only cost-based fees apply.
Rest assured—wherever you are, our extensive partner network is ready to keep your ride running smoothly.
Lifetime Limited Powertrain Warranty & Wrap Program
For added long-term security, our Lifetime Limited Powertrain Warranty and Lifetime Wrap Program provide continued mechanical breakdown coverage for as long as you own your vehicle—with no term or mileage restrictions.
Every product on Hekomart.com is expertly curated from thousands, quality tested, and lifestyle approved. Elevate your everyday.
Express Delivery Priority - Where Speed Meets Satisfaction
At Hekomart.com, we understand the anticipation that comes with every online order. While most platforms rely on standard economy shipping, we prioritize your excitement by strategically selecting premium express carriers to accelerate deliveries. Our intelligent logistics system analyzes real-time data to optimize routes, partnering with globally-recognized couriers like DHL, FedEx, and UPS to ensure 30% faster doorstep arrivals* than industry averages.
Every package receives 24/7 tracking visibility and proactive delivery updates, transforming waiting time into confidence. For time-sensitive purchases, our "Expedited Service Guarantee" offers optional priority handling at no extra cost, because your satisfaction isn't just a goal – it's the core of our delivery DNA.
*Based on internal 2025 data comparing standard shipping durations across major platforms. Delivery times vary by destination and customs procedures.
Credit Card 180 Days Purchase Protection
The 180 Days Purchase Protection protects the buyer if an item purchased has not been shipped or if a shipped item is significantly not as described by the seller. The 180 Days Purchase Protection covers all purchases and payments made through our website. We accept Visa, Master Card, American Express, and Discover Card. If you don't receive the item that you ordered, or it shows up significantly different from its description, you may qualify for Purchase Protection, and we'll reimburse you for the full purchase price plus any original shipping costs, subject to terms and limitations. If you are charged for a transaction that you didn't make, let us know within 60 days, and we've got you covered.
30 Days Money-Back Guarantee
We are confident that our products are of great quality and even better value. However, if upon receiving and inspecting your item you decide that you want to return it, you will have 30 days as of the date of shipment arrival to return it for a refund minus the shipping cost. No restocking charges. Any additional fees associated with a purchase transaction will be deducted from the amount of the refund.
24-Month Extended Warranty Service
If you purchase products from our website, you have 24 months to request repairs or replacement if any products turns out to be faulty or are not as advertised. During the warranty period if any product is found to have a manufacturer defect, we will repair or replace the defective part(s). If a product cannot be repaired or replaced within a reasonable time, you can request a refund or price reduction. We are confident that our products are of great quality and even better value. However, if upon receiving and inspecting your item you decide that you want to return it, you will have 30 days as of the date of shipment arrival to return it for a refund minus the shipping cost.
