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Vvolt Sirius Review

Will Roberson
By
Will Roberson,
Electric Bike Enthusiast
Taylor Moon
By
Taylor Moon,
Contributing Editor
Images from manufacturer's website

40 mi

RANGE

26 mph

TOP SPEED

4 hrs

CHARGE TIME

55 lbs

WEIGHT

Mid-drive

MOTOR TYPE

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Vvolt Sirius Review: Takeaway

Vvolt has taken the basic e-bike recipe and sprinkled just the right amount of tech, style, and capability with the Sirius. The bike looks great, rides well, and is versatile enough to tackle light off-pavement excursions with the stock MTB-type tires. There’s a decent amount of power, but you must also pedal. The assist range is average but sufficient for the likely non-hardcore riders considering the Sirius.

The real magic is in the nearly silent drive system and the sealed Enviolo rear hub that spans a wide range of stepless ratios. Plus, that graceful arcing frame adds a touch of elegance and style. Add whatever accessories you need for commuting, wet weather trips, or riding after dark.

Ideal for...

  • Reliable all-terrain commuting
  • Light-duty mountain biking – when equipped with knobby tires

Vvolt Sirius Review Overview

We’ve always appreciated when something used as an appliance also has a sense of style. Early art-deco radios and such didn’t need to be arthouse objects, but it’s cool that some were — and they are just one example of a compelling design that is attractive to this day. And that is certainly what we like most about the Vvolt Sirius. It’s a fun bike with just enough style to stand out.

The bold arcing frame of the Vvolt Sirius holds some of the better e-bike kits out there, including a mid-mount MPF 6C 350-Watt (650 Watts peak) motor that makes 80 nm of torque and an Enviolo TK rear hub offering a wide range of infinitely adjustable gearing. Instead of a chain, a toothed Gates CDX kevlar belt connects the motor and hub. Power comes from a removable 36-volt, 375-watt/hour battery fitted flush into the lower frame spar. LED lighting, a discreet LCD display, a suspension fork with 100 mm of travel and lockout, hydraulic disc brakes, a gel seat, and a gently swept flat bar round out the package. There’s also a bike bell. Who doesn’t love that?

Our bike was painted creamy white, nicely offset by the black 27.5-inch wheels and 2.2-inch Kenda K1027 knobby tires. The Vvolt Sirius is a Class 1 or 3 lectric bike with pedal assist to 20 mph and no throttle. Our bike was in Class 3 configuration with a top assist speed of 26 mph. While we had the 375-watt/hour battery, a 500-watt/hour version is an optional upgrade. Volt says the base battery is good for 15 to 40 miles of pedal assist, depending on conditions and assist level.

Riding the Vvolt Sirius

Thankfully, the Vvolt Sirius falls closer to a mountain bike riding posture than the more upright commuter position. With the suspension fork in play — it does have lockout — we often pointed it onto gravel and dirt trails in the parks nearby. It was nothing too serious, but we would hesitate to call it “mountain biking.” The Sirius was game and easy to ride on lower-traction surfaces thanks to the decent fork action and reasonably wide Kenda knobbies. Aggressive riding that gets the front wheel aloft can result in a bit of a clunk as the unbranded suspension fork fully extends, but it wasn’t as bad as some bikes we’ve ridden previously.

The Acer Xplova LCD display is small but mighty, providing all of the features you need, as well as a clean cockpit.

Power comes on smoothly from the mid-mount MPF motor, and the bright orange buttons on the small Acer Xplova LCD display toggle between six assist levels, counting “zero assist” as one of them. A torque sensor doles out the power smoothly according to pedaling effort. Motor noise is minimal since the internal reduction gearing swims in an oil bath.

The Sirius is a solid ride on the pavement. For “urban-focused” e-bikes of this type, we often lock out the front fork for pavement riding to increase the front-end feel, and we like the feel of a hardtail on pavement better overall. But it is nice to have the option to bring it back in for a bit of cush up front as needed or wanted. A small knob on the right fork cap locks out motion and allows a fairly distinctive change in feel, and the left cap covers a Schrader valve for adding in air for preload.

The front suspension on the Sirius provides good cushioning on the streets or the trails. Choose your own adventure.

It still takes us a minute to reacquaint ourselves with the Enviolo’s twist-grip controller if it’s been a while since we last used one. The rotation directions for lower and higher gear ratios still seem a bit backward to us, but eventually, some faint muscle memory kicks in, and we make the wrong choice less often.

Enviolo’s internally geared, maintenance-free hubs are still innovative in bicycle gearing systems. Changing gears while at a stop is a huge convenience, especially for new riders. For those of us with decades of derailleur tickling behind us, the ability to pick a perfect ratio for pretty much any real-world riding scenario is a treat. We preferred the manual-style hub over the electric automatic version and were glad to see it on the Sirius. Volt says the TK hub on the Sirius has a 380 percent gearing range from low to high gear. Going up our hill test, we felt something a tick lower for the granny gear might be a good idea, but with the electric assist in play, it’s a moot point.

Rush hydraulic brakes work like a charm and have plenty of stopping power once they are broken in, like most brakes.

The Rush 160 mm hydraulic brakes had good power and feel after bedding in a bit and cut motor power when applied. The LCD display shows the basics but can also toggle to show motor power output in Watts for the more granular wireheads like ourselves.

The Sirius was a very neutral-riding bike, as some commuter-style bikes can have fairly long geometries that affect steering. But the MTB-esqe wheelbase and almost-flat bar make for a more dedicated riding position and allow standing on the pedals on hills if need be. However, that wasn’t needed much, thanks to the toque-rich motor output. The Sirius’ arcing frame gives it a beach cruiser vibe, but only just. Overall, the look is a deft blend of purpose and style.

Vvolt includes a removable bar-mounted LED headlight and a small seat post-mounted rechargeable blinking taillight that is up to par. The LED headlight was adequate at night, but I’d love to have more firepower as we often used an additional light on the bar at night for more robust illumination. As such, the included light was bright from the front and made for a good traffic marker.

Internal stepless shifting is the answer here with 380% gearing range

On the hill test, we could sit and pedal with output set to maximum at a decent pace between 12 and 17 mph depending on the grade, which varies on the paved road up the ancient volcanic butte we had access to. On the serpentine ride down the back side of the butte, the speedometer nearly touched 40 mph on the steepest section with pedals at full tilt. The Sirius railed nicely through a 90-degree banked turn at the bottom of the incline, knobbies humming across the pavement after the brakes scrubbed off some velocity.

Traversing Portland’s many bike lanes In the flat, the Vvolt softly phases in assist when the speedometer dips under 20 mph and quietly signs off when a gentle hill allows gravity to push the speed over that mark. The stock gel seat was comfortable on extended rides while wearing padded cycling shorts. Without them, it was still a comfortable spot to be. The motor gives an audible whir at full power, but it is acceptably quiet and, thankfully, not a whine.

The Sirius is a smooth pedaler with its Gate Carbon 122-tooth belt drive.

On balance, the Vvolt Sirius is a well-rounded, easy-to-ride e-bike with a dash of style to compliment its wide riding portfolio. The mid-mount MPF 6C drive motor and the Enviolo hub smooth out common rough edges around motor and gear management, allowing for a more focused ride experience. Throw in that it can dispatch light off-pavement scenarios and work as a commuter by adding racks and bags, and the Sirius is one of the more capable e-bikes I’ve ridden lately.

But overall, it was mostly fun to just cruise around on the Sirius while perhaps using an errand to get away from the keyboard and cut through some light trails to pick up something at the market or takeout. The special drivetrain bits mean the Vvolt Sirius costs a bit more than similar e-bikes, but improving ride response and smoothness is worth the investment.

Reasons to Buy the Vvolt Sirius

The Vvolt Sirius is a capable and versatile e-bike with a wide range of innovative technologies packaged in a stylish, approachable form factor.

The Sirius features a beautiful, arcing top tube that gives the bike a unique look, but also frame strength. A mid-mount motor coupled to an Enviolo rear hub lets riders tailor the assist and pedal power to a nearly infinite degree. And don’t be afraid to point it off-road as well!

Things to Consider

The Vvolt Sirius is a full-size e-bike with no step-through version. Even with the small frame size option, riders under 5 foot 7 may find themselves on tiptoes at a stop. It takes a minute to get used to the Enviolo hub’s stepless shifter, but it can also be shifted while stopped.

The power system LCD display is small but legible. It would be nice to have battery power shown in percentage rather than (or in addition to) the three small segments.

Vvolt bikes arrive about 90 percent assembled. Getting the front wheel, handlebars, and some small parts in place is relatively simple, but if in doubt, owners may want to pay a bike shop to do the final assembly. Fenders, lights, racks, and a bike bell are not included in the purchase price but are readily available from Vvolt, and most bike shops will install fenders and racks for a fee, so budget carefully if those items are needed.

Protip: Vvolt was charging $100 to upgrade the Sirius to Class 3 ‘warp core’ with a top assist speed of 26 mph, but that upgrade is now included at no additional cost. If you need more range, the 500 watts/hour battery is $549, but Vvolt told ebikes.org they will work with customers directly on pricing who want the 500Wh upgrade but don’t want two batteries. Metal fenders are $140 for the set. Front and rear racks are also available.

Specs & Components

Battery
36V 10.4Ah Integrated Battery 375Wh | LG Cells, 500Wh battery option.
Tires
Kenda K1027 27.5 x 2.2-inch
LCD display
Acer Xplova Displays speed, odometer, trip meter, motor output in Watts. USB port. Strava compatible, Bluetooth built in
Gears
Enviolo TK enclosed geared rear hub – 380% stepless gearing range, manual stepless twist shifter
Front fork
Unbranded air suspension type 100mm travel, quick lockout, compression adjuster
Brakes
RUSH hydraulic disc brakes, 160mm rotors front and rear, single puck calipers
Motor
MPF 6C motor; 350-Watts nominal, 650 Watts peak, mid-mount, oil bath for internal gears
Drivetrain
Gates CDX 122-tooth drive belt

The specs above come from the manufacturer and may vary from what you’ve experienced. Notice something that needs correcting? Let us know.

Ratings

Power
3/5
3

With a torque sensor and mid-drive motor, the assist comes on smoothly with the Sirius. There is no jerkiness in delivery, and with a peak output of just over 650 Watts and 80 nm of torque, the mid-mount motor can flatten hills without much effort when set to maximum assist. It’s tough to tell in the flat it’s even an e-bike, it’s so quiet and smooth.

Range
3/5
3

Range isn’t a strong point with the Sirius, with 40 miles at most with minimal assist from the base battery. But it’s likely plenty for riders attracted to this bike, even at the maximum assist 15-mile range. This is not a race bike or dedicated downhiller; it’s a city bike that can get a bit dirty. And at 55 lbs, it’s still fairly easy to pedal even with no electrical assist.

Comfort
5/5
5

The Vvolt Sirius is a comfortable riding e-bike with a low-stress, MTB rider triangle and a decent seat as stock. While it’s not specifically billed as a “mountain bike,” the riding position is similar, with a slight lean forward onto the flat bars.

Durability
3.5/5
3.5

The Sirius is sturdily built. Maintenance is greatly reduced due to the Enviolo hub’s sealed internals, self-adjusting hydraulic disc brakes, and a carbon belt drive instead of a chain. The front suspension fork reduces stress on head bearings and allows some fun in the dirt. Owners will need to practice good battery management to make the power cell last for many years.

Style
5/5
5

The Vvolt Sirius is a beautiful e-bike, especially in the chalk-white color of our review bike. The gentle arc of the top tube from head to rear axle makes it stand out from other electric bikes. The internal battery placement keeps the bike’s flowing lines clean and simple.

Our Research Methodology

We personally research and test every e-bike featured in our reviews and guides to provide accurate, data-driven recommendations. Learn how we review.

About Our Editorial Team

Will Roberson
Written by Will Roberson
Electric Bike Enthusiast
Will Roberson is a transportation technologies writer in Portland, Oregon, and writes for many publications about e-bikes, motorcycles, cars, and new transportation technologies. He got his first e-bike in 2016 and never looked back.
Taylor Moon
Edited by Taylor Moon
Contributing Editor
Taylor Moon is a seasoned editor and content marketer with a diverse background spanning journalism, entertainment, travel, B2B SaaS, technology, and digital and creative marketing. Outside of her professional realm, she cherishes moments with her husband, daughter, and two dogs, drawing inspiration from both her work and family life.
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