Vivi ACE01 Electric Bike Review: Range, Power, Comfort and UL Safety Tested

BEST VALUE FAT-TIRE E-BIKE

Vivi ACE01 Electric Bike — 750W Torque-Sensor All-Terrain Ride

Our take: a powerful yet affordable 750W fat-tire e-bike with torque sensor, hydraulic brakes and UL-certified battery for confident daily and weekend rides.

4.7/5

• 750W rear hub motor (1475W peak, 90 Nm) flattens steep hills and soft terrain.
• 48V 15Ah removable battery delivers roughly 40–60 miles of real-world range.
• Torque sensor, dual hydraulic brakes and UL 2849 system certification boost control and safety.

Motor

750W hub (1475W peak)

Battery

48V 15Ah (720Wh)

Top Speed

Up to 25 mph

Range

Approx. 40–60 miles

Check Live Price See Pros & Cons

View on Amazon

The Vivi ACE01 is one of those Amazon e-bikes that makes you pause and think, “Is it really giving me all of that for this price?” On paper you get a 750W rear hub motor with 1,475W peak output, a 48V 15Ah (720Wh) battery, hydraulic disc brakes, a torque sensor, 26" x 4.0" fat tires, and SGS certification to UL 2849/2271 – all for around $749.99.

That spec list alone puts it in a very competitive spot in the budget fat-tire category. But specs don’t tell the whole story. What matters is how the ACE01 actually feels on the road, how it climbs hills, whether the torque sensor is tuned well, and if the bike is genuinely comfortable and practical for everyday use.

In this in-depth review, we’ll walk through the Vivi ACE01 from every angle – design, motor performance, range, comfort, safety, and real-world usability – so you can quickly decide if this is the right fat-tire e-bike for your commutes, weekend rides, and light off-road adventures.

Quick Verdict

The Vivi ACE01 is a value-packed fat-tire e-bike built for riders who want serious power, real hill-climbing capability, and the smoother feel of a torque sensor without spending over a thousand dollars. It’s not a lightweight or ultra-refined machine, but as an all-terrain “do-most-things” bike, it hits a sweet spot for the price.

The 750W rear hub motor (1,475W peak, 90 Nm torque) pulls hard up hills, the 48V 15Ah battery offers genuinely usable range, and the hydraulic brakes plus UL 2849/2271 certifications add an extra layer of safety that many similarly priced bikes don’t offer. The trade-offs are predictable: a 72 lb bike weight, a single frame size, basic LCD display, and no high-end brand components.

If you’re a rider between 5'3" and 6'5" looking for a powerful fat-tire e-bike for mixed city and trail riding, and you’re okay with the weight, the ACE01 is very easy to recommend.

At a glance

• Category: Class 3-capable 26" fat-tire all-terrain / commuter e-bike
• Motor: 750W rear hub (peak 1,475W), 90 Nm torque
• Battery & Range: 48V 15Ah (720Wh) removable; about 40 miles throttle / 40–60 miles with PAS depending on rider & terrain
• Top Speed: Up to 25 mph (PAS and throttle)
• Weight & Payload: ~72 lb bike, 330 lb rated payload
• Frame & Wheels: Aluminum frame, 26" x 4.0" fat tires, front suspension fork
• Brakes: Dual hydraulic disc brakes
• Rider Height Range: 5'3"–6'5"
• Best for: Riders who want strong hill-climbing, snow/sand capability, and a more natural torque-sensor ride at a budget-friendly price

What Is the Vivi ACE01?

The Vivi ACE01 is a 26" x 4.0" fat-tire electric mountain bike aimed at adults who want one bike that can handle daily commuting, weekend trail rides, and bad-weather conditions. With its wide 4-inch tires, front suspension, and rear rack, it sits somewhere between a rugged all-terrain bike and a practical city commuter.

Vivi as a brand focuses heavily on budget-friendly e-bikes sold online. Their bikes tend to prioritize strong motors and generous feature lists for the money. The ACE01 follows that formula but adds two notable upgrades you don’t usually see at this price: a torque sensor (instead of the usual cadence sensor) and dual hydraulic disc brakes.

The design goal is clear: offer a powerful, versatile fat-tire e-bike with more refined pedal assist and better safety certification than the typical “no-name Amazon special,” while still staying under the psychological $800 mark.

Key Specs

Spec	Detail
Bike type	Electric mountain / fat-tire / commuting e-bike
Motor	750W rear hub motor (1,475W peak), 90 Nm torque
Battery	48V 15Ah (720Wh) removable lithium-ion, 21700 cells
Claimed range	40–60 miles per charge (depending on mode)
Realistic range	~40 miles throttle only, 45–60 miles PAS with moderate effort for an average-weight rider
Top speed	Up to 25 mph
Bike class	Functionally Class 3 (can reach 25 mph with pedal assist); may be configurable to local limits
Weight / Payload	~72 lb bike; 330 lb max load
Frame material	Aluminum alloy, mid-step frame with integrated battery
Wheel size & tires	26" x 4.0" fat tires, all-terrain tread
Suspension	Lockable and adjustable front suspension fork
Brakes	Dual hydraulic disc brakes
Drivetrain	7-speed gear system
Display & controls	LCD display, 5 PAS levels, throttle, walk assist, cruise control
Battery certification	SGS certified to UL 2849 and UL 2271
Working modes	Throttle, pedal assist, normal bike, cruise control, walking assist
Fit height	Recommended for riders 5'3"–6'5"

These specs put the ACE01 squarely in the “high-powered budget fat-tire” category – but the combination of torque sensor, hydraulic brakes, and UL certifications makes it stand out from a lot of rivals at a similar price point.

Who Is the Vivi ACE01 Best For?

Ideal for

• All-terrain commuters
  If your daily ride mixes paved roads with dirt paths, gravel, or poorly maintained streets, the 26" x 4.0" tires and front suspension soak up bumps and ruts that would rattle you on a skinny-tire city bike.
• Riders in hilly areas
  With 90 Nm of motor torque and a 1,475W peak output, the ACE01 has more than enough punch to tackle steep inclines without forcing you to stand on the pedals. The torque sensor also adds extra assistance when you’re really pushing, which makes hill starts and long climbs feel more controlled.
• Heavier riders and cargo use
  The 330 lb load capacity and sturdy aluminum frame, plus a thickened rear rack, make it a good option for heavier riders or those who regularly carry panniers, groceries, or a child seat (within weight limits and with proper mounting).
• Riders who care about safety certification
  Many budget e-bikes skip UL certification entirely. The ACE01 is SGS tested to UL 2849 for the entire e-bike system and UL 2271 for the battery pack, which means the electrical system has been through standardized safety testing rather than just relying on factory claims.
• Beginners who want a natural ride feel
  The torque sensor is a big deal here. Instead of the on/off surge you get from a basic cadence sensor, the ACE01’s assist ramps up based on how hard you’re actually pedaling. That makes it a lot more intuitive for first-time e-bike riders, especially if you’re transitioning from a regular bicycle.

Not ideal for

• Riders who need a very light bike
  At around 72 lb, the ACE01 is heavy. That’s typical for fat-tire bikes with large batteries, but if you need to carry it up several flights of stairs, this may not be the best choice.
• Shorter riders under 5'3"
  The recommended height range is 5'3"–6'5". If you’re significantly shorter, standover height and reach may feel too large even with the saddle dropped.
• Performance trail riders
  The ACE01 is robust and confident on light off-road trails, snow, sand, and gravel. But it’s not a purpose-built mountain bike with high-end suspension. Serious technical singletrack riders will want something more specialized.
• Riders who need a super-stealthy or minimal look
  This is a big, bold fat-tire e-bike with a rear rack and fenders – more “adventure SUV” than “sleek city fixie.”

Budget & value positioning

At its typical price around $749.99, the Vivi ACE01 lives squarely in the “budget fat-tire” bracket, but the torque sensor, hydraulic brakes, and UL certifications push its value closer to what you usually see in more expensive mid-range bikes.

You don’t get brand-name components or fancy color displays, but you do get the fundamentals done right: strong motor, decent battery capacity, solid stopping power, and a comfortable, versatile platform. For many riders, that’s exactly what matters.

Design, Frame & Build Quality

Visually, the Vivi ACE01 looks modern and cohesive. The battery is semi-integrated into the down tube, the top tube slopes down toward the seat tube to keep standover height manageable, and the rear rack and full-coverage fenders make it look ready for real-world use rather than just catalog photos.

The aluminum alloy frame is designed as a mid-step: not quite a full step-through, but with a noticeably lower top tube than a traditional mountain bike. For most riders in the recommended height range, this makes mounting and dismounting easier, especially if you’re carrying gear on the rear rack. Welds and joints are functional and in line with what you’d expect at this price – not boutique-level sculpting, but nothing that jumps out as worrying or sloppy.

Cable routing is a mix of internal and external. Some wires run through the frame, while others are bundled along the exterior with clips. It’s neat enough that nothing screams “DIY,” and it keeps maintenance straightforward. The rear rack is thickened aluminum with multiple attachment points and pre-drilled holes for baskets or additional accessories, which is great if you plan to commute or tour with panniers.

The included full-length fenders are plastic but reasonably sturdy. They provide good coverage for the large 4-inch tires, which means much less road spray on your back when you hit puddles or ride in slushy conditions. The integrated front LED headlight and rear reflector setup complete the utilitarian look – this bike is clearly meant to be ridden, not just admired in the garage.

Overall, the ACE01’s build quality matches its price band but benefits from thoughtful design touches – especially the robust rack, wide fenders, and integrated battery – that make it feel like a complete package rather than a barebones platform.

Motor Performance & Speed

The star of the show is the 750W rear hub motor, which can peak at 1,475W and deliver up to 90 Nm of torque. Numbers aside, what matters is how it behaves when you twist the throttle or dig into the pedals.

Power delivery

Thanks to the torque sensor, the ACE01’s assist feels more like a strong tailwind than a jerk from behind. When you start pedaling lightly, the bike responds with gentle assistance; when you dig in, the motor wakes up and adds real muscle. That proportional response is a big upgrade over cadence-only bikes that simply blast power whenever the cranks are turning.

On flat ground with pedal assist in the mid-levels, cruising at 18–22 mph feels effortless. Bump up to the higher PAS level and you can approach the bike’s 25 mph top speed without feeling like you’re fighting the motor or spinning out too quickly. The 7-speed drivetrain gives you enough gears to find a comfortable cadence at most speeds, although at the very top end you may still feel a bit of “ghost pedaling” – typical for hub-drive fat-tire e-bikes.

Throttle behavior

The thumb throttle provides full power on demand and is especially useful for quick starts at intersections or when you need a short break from pedaling. It pairs well with the torque sensor: you can ride primarily in pedal assist and then use the throttle to fill in gaps when traffic or terrain demands quick acceleration.

The motor engagement is assertive but not violent. Riders new to e-bikes should still start on lower PAS levels until they’re comfortable, but overall the tuning is more controlled than many budget 750W fat-tire bikes, which can feel almost too eager at low speeds.

Hill performance

Where the ACE01 really shines is on hills. With 90 Nm of torque, it’s designed to handle steeper terrain than many 500W/750W competitors. On moderate hills, you can stay seated, use a middle gear and PAS 3–4, and let the torque sensor automatically boost power as the grade increases.

On very steep climbs, pairing a low gear with high PAS and a bit of throttle gives you that extra push to keep moving without grinding. The motor does its work with a typical hub-drive hum – audible but not obnoxious.

High-speed stability

Fat tires and a longish wheelbase give the ACE01 good stability at speed. Around 20–25 mph, the bike feels planted rather than twitchy. The front suspension and big tires help absorb high-speed chatter, so you’re not constantly knocked off line by small bumps. As always, you still need to respect the 72 lb weight and 25 mph speed; this is a powerful machine and should be ridden with appropriate caution, especially on loose surfaces.

Battery, Range & Charging

The ACE01 uses a 48V 15Ah removable battery based on 21700 cells, giving a total capacity of 720Wh. That’s a nice step up from the 48V 10–13Ah packs you often see in cheaper bikes.

Real-world range

Vivi claims 40–60 miles per charge, which is realistic depending on how you ride:

• Throttle-only riding: Expect somewhere around 30–40 miles if you’re on mostly flat ground and not constantly at top speed.
• Mixed PAS riding: With pedal assist in levels 2–3 and moderate effort, many riders can expect 40–60 miles in typical mixed terrain.
• Hilly, high-speed riding: If you live in a very hilly area and tend to ride in the highest PAS levels, range will drop – think 30–45 miles depending on rider weight and conditions.

As always, rider weight, wind, temperature, and tire pressure will influence these numbers, but the 720Wh capacity provides a comfortable buffer for most day-to-day use.

Charging

The battery can be charged on or off the bike, which is handy if you store the bike in a shed or garage but want to bring the battery indoors. Vivi includes a 3A charger, which is faster than the more common 2A bricks. Expect roughly 4–6 hours for a full charge from low battery, depending on the starting level.

The battery locks to the frame and includes typical protections such as overcharge, over-discharge, temperature monitoring, and cell balancing. Combined with the SGS certification to UL 2849 and UL 2271, that provides additional peace of mind that the pack and electrical system meet recognized safety standards rather than purely internal factory testing.

For daily commuting in the 10–20 mile range, most riders will only need to charge every other day, even with liberal use of pedal assist. Longer weekend adventures are also realistic without “range anxiety,” as long as you stay mindful of your PAS level and speed.

Ride Comfort & Handling

Comfort

Fat-tire e-bikes are inherently comfortable thanks to their massive air volume, and the ACE01 leans into that advantage. The 26" x 4.0" tires can be run at lower pressures for extra cushioning on rough terrain or higher pressures for more efficient road use.

The front suspension fork is both lockable and adjustable, letting you fine-tune the ride depending on where you’re going. For city commuting, you can firm it up or lock it out to reduce bobbing when you’re pedaling hard. For gravel, dirt, or off-road use, leaving it open lets it soak up potholes, roots, and rocks more effectively.

The riding position is moderately upright. The handlebar height (~40.6") and reach strike a nice compromise between control and comfort, so you’re not hunched aggressively forward but also not sitting fully upright like a cruiser. Riders in the medium height range (around 5'7"–5'11") will likely find the default setup comfortable, while shorter or taller riders can adjust the saddle height (32.3"–38.6") to dial in their fit.

The stock saddle is typical for this category – not a premium touring seat, but reasonably padded and shaped. Many riders are perfectly happy after a short break-in period; others may choose to upgrade to a gel or suspension seatpost for longer rides.

Handling & stability

Despite the heavy weight and fat tires, the ACE01 handles predictably. At low speeds, it feels stable rather than twitchy, and the wide bars give you good leverage when maneuvering around obstacles or weaving through traffic.

On loose surfaces like sand, snow, or gravel, the fat tires shine. They provide more float and grip than traditional mountain bike tires, making it easier to maintain balance and control. The tread pattern is versatile enough for both pavement and dirt, though of course you’ll hear a bit more tire noise on smooth surfaces compared with narrower city tires.

When cornering at speed, the ACE01 remains composed as long as you respect the limits of a heavy, high-center-of-gravity fat-tire bike. The combination of wide tires, front suspension, and a long wheelbase helps it track confidently through bends. Braking hard from 20–25 mph, the bike stays relatively straight, with minimal fork dive if the suspension is set up properly.

All told, ride comfort is one of the ACE01’s strong points. It’s the kind of bike you can happily take for a 15–25 mile ride without feeling beat up afterwards.

Brakes & Safety Features

Braking is handled by dual hydraulic disc brakes, which is an important highlight at this price point. Many similarly priced fat-tire bikes still ship with mechanical discs that require more hand strength and frequent adjustment.

Hydraulic brakes generally offer:

• Stronger and more consistent braking force
• Better modulation – it’s easier to apply just the right amount of power
• Less maintenance once properly bedded in

On the ACE01, lever feel is light and progressive. Even when you’re carrying extra weight on the rear rack, stopping from 20+ mph feels controlled, not alarming. The fat tires also play their part, offering plenty of grip on dry pavement and decent traction on packed dirt and gravel. As with any bike, braking distances increase in wet conditions, but the overall system feels appropriately matched to the bike’s speed and weight.

Safety features extend beyond braking:

• Bright front LED headlight for night visibility
• Rear reflector (you may want to add a dedicated rear light for maximum safety)
• Wide tires that provide better stability on rough or slippery surfaces
• UL 2849 / UL 2271 certification for the electrical system and battery, reducing the risk of electrical faults and fire compared with uncertified budget e-bikes

If safety and reliability are high on your priority list, these features should carry significant weight in your decision.

Controls, Display & Riding Modes

The Vivi ACE01 uses a simple LCD display mounted near the center of the handlebar. It’s monochrome but clear, showing key information such as:

• Current speed
• PAS level (1–5)
• Battery level
• Odometer and trip distance

The control pad, mounted within thumb reach on the left side, has dedicated buttons for power, mode selection, and assist level up/down. On the right side, you have the 7-speed shifter and the thumb throttle.

Pedal assist behavior

With its torque sensor, the ACE01’s PAS is more intuitive than the on/off feel of many budget bikes:

• PAS 1–2: Gentle assistance, ideal for casual cruising, bike paths, or when you want to maximize range.
• PAS 3: A good default for mixed city riding – enough boost to hover around 15–18 mph with moderate pedaling.
• PAS 4–5: Strong assistance for fast commuting and hill climbing, letting you reach the bike’s top speed with less effort.

Because assistance is tied to how hard you pedal, you don’t get the “ghost pedaling” feeling as quickly as on cadence-only bikes. If you push harder, the motor pushes harder; if you ease off, it does too.

Throttle, cruise control & walk assist

• Throttle mode: Works independently of pedaling and is especially helpful at traffic lights, steep hill starts, or when you’re simply tired and want a break.
• Cruise control mode: Allows you to maintain a steady speed without holding the throttle down continuously – useful on long, flat sections.
• Walking assist mode: Provides gentle power to help you push the bike up ramps or hills while walking alongside it. Given the 72 lb weight, this mode is genuinely useful.

There’s no dedicated smartphone app or Bluetooth connectivity here, but the core controls are straightforward and do what most riders actually need day to day.

Fit, Sizing & Adjustability

The ACE01 is designed as a one-size-fits-most frame, with a recommended rider height range of 5'3" to 6'5". That’s a wide range, and in practice the bike will feel different depending on where you fall in it.

Key dimensions:

• Total length: 76"
• Handlebar height: 40.6"
• Handlebar length: 26.4"
• Wheelbase: 47.2"
• Wheel diameter: ~28.3" (26" rims with 4" tires)
• Seat height range: 32.3"–38.6"
• Top tube length: 27.6"

For average-height riders, these numbers translate into a comfortable, slightly upright position with good control. Taller riders near the top of the range may want to slide the saddle back slightly to gain more leg extension, while shorter riders may need the saddle close to its minimum height.

Because the frame uses a sloping top tube, standover height is reasonable for a fat-tire bike, but riders at or below 5'3" should pay close attention here – mounting and dismounting might still feel tall, especially with the bike loaded.

If you’re on the edge of the height range or have shorter legs and a longer torso (or vice versa), expect to spend a bit of time fine-tuning saddle height and fore-aft position to get your fit dialed in. Once set up, the bike’s geometry is more “all-terrain comfort” than “race-ready aggressive,” which suits its intended use perfectly.

Assembly & Out-of-the-Box Experience

Like most direct-to-consumer e-bikes, the Vivi ACE01 arrives about 85% pre-assembled. The bike is well-protected in foam and cardboard, and major components are secured to prevent damage during shipping.

Typical assembly tasks include:

• Attaching the front wheel
• Installing the handlebar onto the stem
• Mounting the front fender and headlight
• Screwing in the pedals (remember left pedal is reverse-threaded)
• Adjusting the saddle height and handlebar alignment

For someone comfortable with basic bike tools, plan on roughly 45–60 minutes from box opening to first ride. Vivi includes the necessary tools and a user manual; even if you’re new to bike assembly, the process is straightforward if you follow the steps methodically.

It’s always a good idea to double-check:

• Brake rotor alignment and lever feel
• Tire pressure (they often ship under-inflated for safety)
• Gear shifting smoothness

If you’re not comfortable with these checks, a quick visit to a local bike shop for a safety inspection is money well spent.

What’s Included in the Box?

In the box:

• Vivi ACE01 electric bike (partially assembled)
• 48V 15Ah removable battery
• 3A battery charger
• Integrated front LED headlight and rear reflector
• Full-coverage front and rear fenders
• Sturdy rear cargo rack
• Pedals
• Basic multi-tool and assembly hardware
• User manual and warranty information

Our take on the package

For a sub-$800 e-bike, the accessory package is generous. You don’t need to immediately budget for a rack, fenders, or lights – the essentials are already there. The only things many riders might still want to add are:

• A brighter or brake-activated rear light
• A more personalized saddle if you have specific comfort preferences
• Panniers or a trunk bag to take advantage of the rear rack

But out of the box, the ACE01 is genuinely ready to commute, run errands, or head out for an evening ride without extra purchases.

Pros & Cons

Pros vs. Cons at a glance

Pros	Cons
Strong 750W motor with 1,475W peak and 90 Nm torque	Heavy at ~72 lb; not ideal for carrying upstairs
Torque sensor for smoother, more natural pedal assist	One frame size only; shorter riders may find it tall
Dual hydraulic disc brakes for confident stopping	Basic monochrome LCD display; no app integration
48V 15Ah (720Wh) battery with realistic 40–60 mile range	Rear lighting is limited to a reflector; most riders will want an active rear light
26" x 4.0" fat tires handle sand, snow, and rough roads	Not a purpose-built mountain bike for aggressive singletrack
SGS certified to UL 2849 and UL 2271 for added electrical safety
Sturdy rear rack and full fenders included

Overall, the pros clearly outweigh the cons for the ACE01’s intended purpose. The main compromises – weight, basic display, and generic components – are typical of this price bracket, while the strengths (torque sensor, hydraulic brakes, UL certification) are genuinely above average.

How the Vivi ACE01 Compares to Alternatives

There are plenty of fat-tire e-bikes on the market, especially in the 750W, 48V class. Here’s how the ACE01 stacks up conceptually against common alternatives in this category:

• Versus typical cadence-sensor fat-tire bikes
  Many budget fat-tire e-bikes around this price or slightly below use a cadence sensor and mechanical disc brakes. The ACE01’s torque sensor and hydraulic brakes give it a more refined ride feel and stronger braking. If you’ve never liked the “on/off” surge of other e-bikes, this is a big plus.
• Versus more expensive mid-range fat-tire bikes
  Step up a few hundred dollars and you’ll often find bikes with branded drivetrains, nicer color displays, integrated brake lights, and sometimes bigger batteries. If those touches matter a lot to you and budget is more flexible, it may be worth looking higher up the ladder. But purely in terms of motor power, real-world range, and core capability, the ACE01 keeps up surprisingly well.
• Versus lightweight commuter e-bikes
  A slim city e-bike with 2.0–2.4" tires will be lighter, more nimble on smooth pavement, and easier to carry up stairs or onto trains. However, it won’t match the ACE01’s comfort, off-road ability, snow/sand performance, or high-load cargo potential.

In short, choose the Vivi ACE01 when you want maximum versatility and power per dollar and you’re comfortable living with a heavier, more rugged machine. Consider other options if you prioritize low weight, premium finishes, or niche performance (like technical mountain biking).

Common Questions About the Vivi ACE01

Final Verdict – Should You Buy the Vivi ACE01?

Score: 8.7 / 10 (value-focused fat-tire all-rounder)

The Vivi ACE01 electric bike ticks a lot of boxes that matter for real-world riders:

• Powerful 750W motor with serious hill-climbing muscle
• Torque-sensor pedal assist that feels more natural and intuitive than typical cadence-only systems
• Large 48V 15Ah battery that delivers genuinely useful range
• Dual hydraulic disc brakes and UL 2849 / UL 2271 certification for added safety
• Fat 26" x 4.0" tires and front suspension that make rough roads, snow, and gravel far less intimidating
• Practical touches like a sturdy rear rack, full fenders, integrated lighting, and multiple ride modes

The compromises – weight, a single frame size, a basic display, and generic components – are real but expected at this price. For many riders they’ll be easy to live with, given the overall performance and safety features the ACE01 brings to the table.

If you’re shopping for a budget-friendly fat-tire e-bike that can handle commuting, weekend exploration, and year-round riding on mixed terrain – and you want the smoother feel of a torque sensor plus the security of UL-tested electronics – the Vivi ACE01 absolutely deserves a place near the top of your shortlist.

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