EUYBIKE S4 E-Bike Review: Dual-Motor Fat Tire Power With Serious Trade-Offs

The EUYBIKE S4 sits at the high-powered end of the fat tire e-bike market, built for riders who want serious climbing ability, long range, and the option to tackle rough terrain on a single platform. It is not a lightweight city commuter. This is a dual-motor, moped-style e-bike aimed at heavier riders, hill-heavy routes, and mixed-terrain use where a standard single-motor bike falls short.

If you are searching for an honest EUYBIKE S4 Electric Bike Review before spending your money, this article breaks down what the specs actually mean for daily riding, who this bike suits, and where its trade-offs show up in the real world.

The S4 carries a 52V 25Ah battery, a claimed 3000W peak dual-motor system, and fat tires designed to handle pavement, gravel, and softer ground. At roughly 90 lbs, it demands respect when it comes to transport and storage.

Bottom Line

The EUYBIKE S4 is worth a close look for riders who prioritize power, range, and load capacity over portability.

It is built for demanding use cases that most lightweight commuter e-bikes simply cannot handle.

EUYBIKE Dual Motor 3000W Peak Electric Bike for Adults, 20″x4.0″ Fat Tires 80Miles Ebike with Removable 52V 25AH Battery, Dual Turn Signal Hydraulic Disc Brake Full Suspension Electric Bicycles

$1,299

EUYBIKE S4 Electric Bike Overview

Quick Verdict

The S4 is designed for riders who need high torque, a generous load capacity, and the range to cover longer distances without recharging. Based on the listed specifications, it fits heavier riders, those tackling steep hills regularly, and anyone needing a capable off-pavement option.

It is not a good match for riders who need to carry or store a bike in tight spaces, or for anyone expecting a lightweight daily commuter. The 90 lb weight is a real barrier for some buyers.

Riders should also be aware that the dual-motor top speed claim of 37 mph places this bike outside Class 3 e-bike limits in most U.S. states. Local regulations should be checked before riding in full power mode on public roads.

Main Specifications

Dual-Motor Power And Speed

Hill Climbing And Torque Claims

The S4 lists a combined torque output of 200 N·m across both motors and a 40-degree max climbing grade. For riders comparing this type of bike, those numbers put it well above most single-motor fat tire e-bikes on the market.

The dual 1500W peak motors are positioned to handle sustained hill work rather than short bursts. Based on the listed specifications, the S4 should manage steep residential grades, unpaved inclines, and heavier rider loads without motor strain.

Real-world climbing will depend on rider weight, road surface, and assist level selected.

Street Use And Local Rule Considerations

A claimed 37 mph top speed in dual-motor mode puts the S4 beyond Class 3 e-bike limits in most U.S. states. Class 3 caps out at 28 mph with pedal assist. The S4 in full dual-motor mode operates more like a moped in terms of speed.

Riders should check their state and local rules before using the bike at full power on bike lanes, paths, or shared roads. Some jurisdictions may require registration, a helmet by law, or restrict use to private property above certain speed thresholds.

52V 25Ah Battery And Real-World Range

Charging And Removable Battery Design

The 1300Wh battery removes from the frame with a key lock, which helps with theft deterrence and makes charging indoors more practical. A full charge takes 5 to 6 hours, which is reasonable for a battery of this size.

The removable design also matters for riders who cannot easily bring the whole bike inside for charging. Apartment dwellers and those with limited storage access will appreciate being able to pull just the battery.

What To Expect Outside Claimed Mileage

The 100-mile range claim applies to light pedal assist at lower speeds. In practice, range drops significantly with heavier riders, higher assist levels, steeper terrain, or colder temperatures.

For riders comparing this type of bike, a realistic everyday range in mixed conditions is likely closer to 40 to 60 miles. Full electric mode with minimal pedaling will also reduce that figure. The 1300Wh capacity is generous, so even at reduced real-world range it remains competitive.

Full Suspension And 20 x 4.0 Fat Tire Ride Feel

Rough Roads And Mixed-Terrain Stability

The S4 pairs a lockable hydraulic front fork with a rear shock absorber, giving it a full suspension setup suited to broken pavement, gravel paths, and packed dirt. The 20″ x 4.0″ fat tires add another layer of compliance over uneven ground.

Based on the listed specifications, the combination should absorb most common road imperfections without requiring the rider to slow significantly. The tire width also improves stability on loose surfaces like gravel and sand.

Comfort Trade-Offs From The 90 Lb Build

The weight of the bike itself creates some comfort trade-offs. Maneuvering at low speeds or walking the bike takes more effort than a lighter model. Tight turns and parking in crowded areas become more physical.

The faux leather saddle is a standard inclusion at this price tier. Riders planning longer trips may want to swap it for a more ergonomic option. The frame geometry leans moped-style, which suits upright riding over long distances but may feel unfamiliar to riders coming from a traditional bicycle.

4-Piston Hydraulic Brakes And Rider Control

Stopping Confidence At Higher Speeds

The S4 uses 4-piston hydraulic disc brakes with 203mm rotors front and rear. At the claimed speeds this bike can reach, that braking setup is necessary rather than optional. Hydraulic brakes respond to lighter lever pressure than mechanical disc brakes and maintain consistent feel across wet and dry conditions.

Based on the listed specifications, the 203mm rotor size is appropriate for a bike of this weight and speed range.

Why Brake Quality Matters On Heavy E-Bikes

A 90 lb e-bike carrying a 250 lb rider at 30+ mph carries significant stopping distance. Mechanical disc brakes or rim brakes would be undersized for that combination. The hydraulic setup here is one of the S4’s stronger practical features, not just a spec sheet item.

For riders comparing this type of bike, brake quality is one area where the S4 appears well-matched to its own performance ceiling.

Fit, Daily Use, And Ownership Reality

Size, Load Capacity, And Rider Match

The S4 supports up to 400 lbs of rider and cargo load, which makes it one of the more capable options for heavier riders in this category. The 20″ wheel size keeps the standover height manageable for a range of riders.

The bike weighs approximately 90 lbs. Riders who need to lift it into a truck bed, carry it up stairs, or load it onto a rack should factor that into their decision. Transport without a ramp or mechanical aid is difficult for most people.

Who Should Buy It

• Riders over 220 lbs who need a high-load-capacity e-bike
• Commuters or trail riders on hilly or rough terrain
• Riders who want long-range capability with a removable battery
• Buyers who want dual-motor power for steep or demanding routes

Who Should Not Buy It

• Riders who need to carry or store the bike in tight spaces
• Anyone primarily riding on flat, paved bike paths at moderate speeds
• Riders in jurisdictions with strict e-bike class speed limits who plan to use public paths
• Buyers looking for a lightweight or easily portable e-bike

Pros & Cons

EUYBIKE Dual Motor 3000W Peak Electric Bike for Adults, 20″x4.0″ Fat Tires 80Miles Ebike with Removable 52V 25AH Battery, Dual Turn Signal Hydraulic Disc Brake Full Suspension Electric Bicycles

$1,299

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Pros:

• Dual-motor system with strong torque for hills and heavier loads
• 1300Wh battery capacity supports long-distance riding
• Removable and lockable battery adds practical charging flexibility
• 4-piston hydraulic disc brakes with 203mm rotors suit the bike’s weight and speed
• Full suspension handles rough and mixed terrain
• 400 lb load capacity covers a wide range of riders
• Shimano 7-speed drivetrain for smooth pedal-assist transitions

Cons:

• 90 lb weight makes transport and storage genuinely difficult
• Claimed 37 mph top speed exceeds Class 3 limits in most U.S. states
• Moped-style frame and high weight are not suited for traditional bike lanes at full power
• 100-mile range applies to ideal conditions; real-world range will be lower
• Higher price point than entry-level single-motor fat tire e-bikes
• Requires assembly and the alloy steel frame adds to overall weight

Customer Reviews

The S4 is a relatively new listing and carries a limited number of ratings at this time, though the early feedback is well-rated. Buyers appear drawn to it primarily for its power output and load capacity.

Among the positive feedback, riders note satisfaction with the motor performance on hilly routes and the quality of the braking system. The battery size and removable design also receive favorable mentions from buyers who value charging flexibility.

Critical notes touch on the bike’s weight as a real-world challenge, particularly for riders who expected easier transport. A few buyers mention that initial assembly requires care and patience to complete correctly.

The consensus from early reviewers supports the S4’s core strengths: raw power, range capability, and braking confidence. Buyers who go in knowing the weight and speed class implications tend to be more satisfied with the purchase.

Final Verdict

This EUYBIKE S4 Electric Bike Review comes to a straightforward conclusion: it is a capable, high-powered fat tire e-bike that delivers on its core promise for the right buyer.

The S4 earns a clear recommendation for heavier riders, hill-heavy routes, and longer-distance use where most single-motor e-bikes fall short. The 3000W peak dual-motor system, 1300Wh battery, and 4-piston hydraulic brakes form a coherent package for demanding riding conditions.

The trade-offs are real and worth stating plainly. The 90 lb weight limits how easy this bike is to move, store, or transport. The top speed in dual-motor mode exceeds typical Class 3 legal limits, so riders need to understand local rules before riding at full power on public roads.

For riders who fit the intended use case, the S4 offers a level of power and range that is genuinely useful rather than just impressive on paper. For everyone else, a lighter single-motor option is likely a better fit.

Preview	Product	Price
	EUYBIKE Dual Motor 3000W Peak Electric Bike for Adults, 20″x4.0″ Fat Tires 80Miles Ebike with…	$1,299	View on Amazon