Balance Bikes >>
HKM-9479379 20-Inch Electric Balance Bike for Kids with 350W Brushless Motor Hydraulic Disc Brakes and Adjustable Suspension
HKM-9479379
The PRO EXTREME: Hydraulics Front and Rear
The HKM-9479379 is the FXB01-20PRO EXTREME, a 20-inch all-terrain balance bike with the hardware grown riders ask for: hydraulic disc brakes on both wheels, a double-shoulder hydraulic suspension fork with adjustable damping, and a 350W brushless hub paced across three modes from 4 to 13 mph. The removable waterproof 36V battery keeps the range coming, the saddle travels 17.7 to 20.9 in, and the aluminium alloy frame carries riders up to 154 lb.
Key Features
Six details that define the FXB01-20PRO EXTREME.
Hydraulic Discs, Both Ends
Hydraulic disc brakes front and rear give one-finger stopping power with a bite that modulates instead of grabbing. It is the brake system adult bikes take for granted, built into this bike for wet grass, trail dust and steep driveways alike.
A Double-Shoulder Hydraulic Fork
The adjustable hydraulic fork with double-shoulder crowns absorbs the hits that rattle small hands and sends rigid forks off line. Set it for the rider and the terrain, and the front wheel stays tracking when the ground turns rough.
Three Speeds, 4 to 13 mph
Three modes pace the ride: roughly 4 mph for first laps, 9 mph for the confident stage and 13 mph for open ground. The 350W brushless hub pulls smoothly through each, and parents keep the switch under adult control until the rider earns the top end.
A Removable, Waterproof 36V Pack
The 36V battery comes out of the frame for charging, seals against the weather for riding, and is available in different capacities to match the session. Charge it at the wall or in the bike; the mount contacts are the only thing to keep clean.
A Saddle That Grows With Them
The saddle travels from 17.7 to 20.9 in, which spans the growth years on one bike. The honest fit check is both feet flat while seated, and this range means the check keeps passing season after season.
Built to 154 lb
The full shockingproof aluminium alloy frame carries riders up to 154 lb at a 39.7 lb net weight. It is the sturdy, all-terrain platform the PRO EXTREME name promises, sized for young riders and built to be handed down.
Overview
A 20-inch all-terrain balance bike with hydraulic brakes and adjustable suspension.
The HKM-9479379 is the FXB01-20PRO EXTREME, a 20-inch electric balance bike built for riders who take the rough path on purpose. A 350W brushless hub motor drives three speed modes paced from 4 to 13 mph, hydraulic disc brakes stop both wheels with one-finger control, and the double-shoulder hydraulic fork adjusts to the rider and the terrain. The removable waterproof 36V battery keeps charging simple, the saddle travels 17.7 to 20.9 in through the growth years, and the full shockingproof aluminium alloy frame carries riders up to 154 lb. It is all-terrain hardware, honest about its job and built to last several riders.
One Finger, Both Wheels
Hydraulic disc brakes front and rear.
Hydraulics change how a young rider brakes: the bite builds progressively, one finger is enough, and loose ground stops turning a squeeze into a skid. With discs at both ends, the PRO EXTREME stops the way adult bikes do.
Full Specifications
Everything worth knowing, in one table.
Why Adjustable Suspension Matters
A fork set for the rider teaches better than one set for the box.
Suspension only works when it matches the rider, which is why the PRO EXTREME makes its hydraulic fork adjustable rather than fixed. Set too soft, the fork pogo-sticks under braking; set too hard, it might as well be rigid. Set right, it keeps the front wheel tracking through the roots and ruts that end short rides, and the hands stay fresh long enough for the brake lessons to land. Around that fork sits a 350W brushless hub with three speed modes from 4 to 13 mph, hydraulic disc brakes at both wheels, and a removable waterproof 36V pack that keeps the charging simple. The aluminium alloy frame takes the hits an all-terrain life hands out, rated to 154 lb with a 17.7 to 20.9 in saddle range.
What’s in the Box
What arrives in the box, ready to build.
1 x 20-Inch PRO Bike
Frame, fork and wheels come fitted from the box
1 x 36V Removable Battery
Seated in the mount and matched to the charger
1 x Mains Charger
Matched to the battery pack from the factory
1 x Seat and Post
Fitted, ready to set for the height of the rider
1 x Manual and Hex Keys
Setup sheets with the tools supplied in the pack
1 x Warranty Card
Registration details for the records at home
Why Choose the HKM-9479379
Six reasons families pick the HKM-9479379.
Brakes That Build Trust
Hydraulic discs modulate instead of grabbing, so young riders learn to feather a brake rather than fear it. That trust shows up everywhere: steeper driveways, tighter corners, calmer parents.
A Fork That Fits the Rider
The double-shoulder hydraulic fork adjusts to the weight and the terrain, which is what makes suspension a teaching tool instead of a spec sheet line. Comfort keeps the lessons going.
A Pace for Every Stage
Three modes from 4 to 13 mph mean the bike is never too slow to be fun or too fast to be safe. The mode moves with the rider, and the top end stays earned rather than assumed.
Battery Out, Charging Simple
The removable 36V pack charges at the wall or in the frame and seals against the weather on the trail. Different capacities let families match the pack to the session.
One Bike Through the Growth Years
The saddle travels from 17.7 to 20.9 in and the frame carries up to 154 lb, so the bike fits the rider for seasons rather than months. Hand-me-downs work when the hardware holds.
All-Terrain by Design
The full shockingproof aluminium alloy frame, 20-inch wheels and rugged build are meant for the rough path. This is the bike that turns park laps into proper rides.
Frequently Asked Questions
Straight answers about the HKM-9479379.
What ages and heights does the HKM-9479379 fit?
The 20-inch PRO platform suits riders moving up from smaller balance bikes, with the saddle travelling from 17.7 to 20.9 in and a 154 lb load rating. The honest check is both feet flat while seated with knees slightly bent, hands reaching the bars at full but comfortable extension. Because this bike carries hydraulic brakes and speed, also confirm the rider can hold the bars and work both levers with one finger before choosing the higher modes.
How do the three speed modes work?
The modes pace the bike at roughly 4, 9 and 13 mph through the 350W brushless hub, and the switch belongs to the adults. Start at 4 mph on flat, open ground until the throttle and both brake levers are under smooth control, then move up one mode at a time as the rider earns it. The top mode is for open ground and experienced hands, and picking the mode for the path is the habit worth building.
Do hydraulic brakes need maintenance?
Very little. The system is sealed, so there is nothing to lubricate, and pad wear at this power level is slow. Check the lever feel weekly: a bite well before half travel means all is well, a spongy lever means air in the line and a visit to support. Keep the rotors clean with isopropyl alcohol after muddy rides, because a firm lever with a clean rotor is the healthy baseline.
How should the fork be set up?
Set the adjustable fork so it compresses about a fifth of its travel with the rider seated: too soft and it pogo-sticks under braking, too firm and it might as well be rigid. After muddy rides, wipe the stanchions clean so grit never drags past the seals. Recheck the setting after growth spurts, because the right setup follows the rider, and store the bike fork-up so the seals stay lubricated evenly.
How does the removable battery work?
The 36V pack unclips from the frame and charges at any wall socket, or it charges in place on the bike. It seals against the weather for riding, and different capacities are available to match longer sessions. Keep the mount contacts clean during the weekly walkaround, bring the pack indoors on cold days before judging its charge, and store it away from direct sun at room temperature.
What assembly and upkeep are involved?
Assembly covers the handlebar, saddle height, fork setup and battery seating, with the supplied hex keys and the manual. Beyond that: tire pressure weekly, a brake squeeze test before rides, clean stanchions after dusty rides and a wipe-down. There is no chain on the hub-motor drive, so nothing needs oiling or tensioning all season. The whole routine fits a weekend morning.
Quick Troubleshooting
When the HKM-9479379 needs attention, start here.
The bike will not power on
Unclip the pack and seat it back until the latch clicks, because a pack just short of home makes no contact. Press the power button and watch for the indicator. If it stays dark, charge for half an hour and retry, check the mount contacts for grit, and confirm the wall socket with another device first. Cold packs read empty until warmed, so bring the bike indoors before judging a winter battery, and make the click part of the pre-ride routine.
The brake lever feels spongy
A spongy hydraulic lever means air in the line, not a worn pad, and bleeding the system is a job for support or a shop. First confirm the lever still bites and the rotor is clean, then contact support with a note of when the feel changed. Spongy levers are a support job, not a trailside fix, so stay off steep terrain until the firm bite returns.
The fork lost its smoothness
Wipe the stanchions with a clean cloth and check for dried mud, which drags past the seals. Cycle the fork through its travel a few times to redistribute the lubricant. If the stiction persists with clean stanchions, note when it started and contact support before disassembling anything. A sag check takes a minute and keeps the setup honest after big changes in rider weight.
The range keeps shrinking
Compare riding style before blaming the pack, because hills and the top mode use far more per mile than cruising. Check tire pressure, since soft tires cost range twice. Cold weather trims every lithium pack. If nothing has changed, run one full uninterrupted charge cycle and retest the same loop. Log the loop you retest on, because different routes make different numbers, and retest before replacing anything.
The motor cut out mid-ride
A pack running low or hot will step back before it dies, so start with a full charge and a cool-down. Check the throttle connector for a half-seated plug and confirm the mode switch has not been nudged. If cutouts continue on flat ground in the low mode with a full, cool pack, note the mode in use and contact support. Log when it happens: climbs point to the pack, flat-ground cutouts point to the controller.
The charger light never turns green
Confirm the wall socket with another device, then reseat the charger plug at both ends. Check the pack mount contacts for grit and charge indoors at room temperature, because cold packs refuse a full cycle. If the indicator still never completes, stop forcing cycles and contact support with a note of how long charging has taken recently. Do not leave a stalled pack on the charger unattended overnight while you wait to retest.
Service & Policies
Coverage that rides every trail with you.
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.
Important Safety Notes
Read these notes before the first ride on the HKM-9479379.
The HKM-9479379 is an all-terrain electric balance bike with hydraulic braking, so a certified helmet is mandatory before every ride, with closed shoes and snug laces completing the kit. Start in the 4 mph mode on flat ground until the rider has both levers and the throttle under smooth control, with an adult approving every mode change. Confirm the battery is fully latched before each ride, squeeze both levers to feel the bite, and check the fork and axle hardware for torque. Keep fingers, laces and loose clothing clear of the hub, rotors and stanchions while powered, and let hot parts cool after long sessions. Charge the 36V pack indoors at room temperature on a hard surface, unplug once the indicator shows full, and never carry a passenger.
HKM-9479379 - 20-inch FXB01-20PRO all-terrain electric balance bike with a 350W brushless hub motor, three speed modes up to 13 mph, hydraulic disc brakes front and rear, a double-shoulder adjustable hydraulic fork, a removable waterproof 36V battery and an aluminium alloy frame rated to 154 lb. Read the manual before first use. Nothing here is safety certification advice.
Every product we offer includes a 180-day purchase protection plan at no additional cost. This coverage extends beyond a standard warranty, reflecting our confidence in product quality and our ongoing commitment to your satisfaction.
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The 180-day purchase protection includes accidental damage and performance failures that are typically not covered by a standard warranty. It provides an additional layer of support during the first six months after purchase, giving you greater confidence and peace of mind.
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The warranty is designed to be simple and accessible. You only need your proof of purchase to begin a claim, and our team will assess the issue promptly. If a manufacturing issue arises, we will make it right.
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Comprehensive Coverage
Every part warranted for two full years.
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Contact Information
24/7 Phone
+1 (209) 280-3200
support@hekomart.com
Address
3401 Dale Rd, Modesto, CA 95356
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Available 24 hours a day, 7 days a week
