Vvolt Sirius Electric Bike Review

If you’re searching for a high-quality, moderately affordable, but capable, electric mountain bike with all the key features, then the Vvolt Sirius e-bike might be for you.

I love its sleek matte finish, integrated battery design, and all its advanced capabilities. If you took all the e-bikes on the market today, about 5% feature a mid-drive motor, and around 2% have a belt drive with an internally geared drivetrain. Vvolt Sirius has all that, and more.

You can easily ride this e-bike to work, to the store, cruise around the town, or even light offroad dirt trails. Front suspension forks and cushiony seat of the Vvolt Sirius provide ample comfort over moderate bumps and dirt terrain. 

Frame

The first thing you’ll notice when you take a look at the Vvolt Sirius is its sleek design. To most people that are passing by, this might not even look like an e-bike. Its mid-drive motor is hidden under the frame and the built-in battery seamlessly integrates right into the down tube.

Built with lightweight aluminum alloy, this electric bike weighs just 54 pounds, which is light enough to hang from a hook in your garage or to load into a truck.

To fit all riders, the Vvolt Sirius comes in two sizes – the S/M size (79-inch stand-over height and a 44-inch seat tube) and the M/L size (83-inch stand-over height and a 48-inch seat tube).

Both of these sizes offer plenty of seat height adjustability - you can even roll the handlebars back or forward to your liking with a quick and easy bolt adjustment.

With a standard electric mountain bike design and handlebars that are raised, the seating position is upright and pretty comfortable with minimum leaning forward even if the seat post is extended.

Vvolt Sirius e-bike offers a front air-sprung suspension fork. This is standard and pretty nice to see on an electric bicycle with dual-sport capability like this.

With adjustments for pre-load which is the ability to modify how easily the forks depress and lockout which keeps the suspension rigid, this e-bike provides pretty good comfort over street potholes and light off-road terrain.

The Vvolt Sirius can easily handle light trails. If you wanted additional suspension without breaking the bank, you could just add an affordable suspension seat post for around $40. This would offer far greater comfort, especially when going on bumpy roads.

A lot of electric bicycles offer simple sprocket/derailleur setups. Very few come with higher-end internal hub geared drivetrains like the Vvolt Sirius. Along with its belt drive, this feature really sets this electric bike apart.

Instead of having different-sized sprockets and a chain shifter to switch between them, this e-bike takes care of all that in a small hub casing found in the rear wheel. As a result, you won’t have to get your gearing modified every couple of months as the derailleur slips out of place.

Also, you can shift gears while the e-bike is under heavy load. This offers substantial flexibility over chain-driven models. The e-bike’s internally geared system provides a lot to the riding experience too.

Motor

The Vvolt Sirius features a 250W MPF mid-drive motor that offers 80Nm of torque.

Firstly, mid-drive motors generally provide much more power than their hub motor counterparts.

Even though 250W sounds rather low, it’s the same size as most high-end electric mountain bikes.

This electric bike’s motor is powerful enough to overcome roads in front of it – climb up steep hills or ride up to 26mph while still being able to pedal.

Listed at 80Nm of torque, this bike’s motor peaks at 500W and is pretty powerful, comparable to many 750W rear hub motors. 

Vvolt Sirius isn’t meant for climbing extreme steep grades, but it should overcome just about any hill you throw at it. This electric bike’s motor won’t leave you asking for more. And you will most likely be more than satisfied with it.

The Vvolt Sirius comes with a torque sensor that controls how much pedal assistance is distributed out to the rider based on how much force the rider puts onto the pedals.

If you are riding in pedal assist level 5, the highest level, you have tremendous power at your disposal; however, the torque sensor won’t distribute all of it out if you are moderately pedaling.

Once you pedal hard, the torque sensor will give you full power. This is a great feature to have on an e-bike since many similar models at this price range don’t have this capability.

Battery

Vvolt Sirius comes with a 375Wh, 10.4Ah 36V Celxpert battery that features LG lithium-ion 18650 cells. This battery is on the lighter side capacity-vise since most electric bikes in this price range offer much larger 48V batteries. 

Vvolt advertises this battery to provide up to 40 miles of riding on a single charge. However, the practice has shown about half that range. Some lighter riders might be able to pull out more, but not much. Heavier riders might only get 20 to 25 miles out of a single charge.

This electric bike comes with a display screen which is on the left side of the handlebar. The display screen is just the right size – not too bulky and not too small.

The digital display showcases three bars to express the charge level left in the battery. The battery on this e-bike also has green and red indicator lights to indicate the capacity.

Vvolt says it takes around 5.5 hours to fully charge the battery, which is on the longer side.

All in all, I wish Vvolt included a better battery.

Brake Type

The Vvolt Sirius comes with hydraulic disc brakes - which provide much better stopping power compared to mechanical disc brakes, which is a welcome sight.

Although, I wish it had 180mm rotors, and not the 160mm ones that are included. But overall, the brakes on the Vvolt Sirius offer sufficient and smooth stopping power.

A simple two-finger pull of the rear or front brake lever brings the bike to a stop with ease. Unless you are an e-bike aficionado, you won’t even notice the difference in braking performance. You can always opt for an upgrade and put some better brakes on your bike which will cost you more.

Rims

This electric bike has 27.5-inch rims. This is a standard size for electric mountain bikes and, all in all, decent quality rims.

Tires

Vvolt Sirius features Kenda 27.5 x 2.2-inch tires which are quite capable of trail riding. Although the size of these tires doesn’t sound like a lot, it’s enough for riding on moderate trails. With that being said, don't expect to ride Vvolt Sirius on extremely rough terrain.