smooth out those rough roads

Sporty on all terrains, Sirius shines on potholed pavement and graveled country roads alike. Our smooth motor-assist system is ready for the rough with handling optimized for unpaved routes while the adjustable fork tames the bumps.

Now on sale for $2199

  • range

    15-40 mi*

  • power

    650 W

  • speed

    26 mph*

  • weight

    55 lbs

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the stuff you probably want to know

Sirius Key Highlights

Off-road capable

An air sprung fork tames bumps and knobby tires maintain traction when the trail (or your commute!) gets a bit rough

Smooth shifting

With the Enviolo internal gear hub, just twist the shifter to find your perfect gear. There’s no such thing as a “missed shift” with this step-less system that provides a wide gearing range. Unlike derailleur gears you can shift anytime – while pedaling, coasting or stopped!

Stop with confidence

Stopping duties are handled by powerful hydraulic brakes which self-adjust for consistent power as the pads wear. We specify brakes with mineral oil as it lasts longer between service and is less toxic for our world.

reviewers love Sirius:

Polished...smooth...remarkably comfortable

It’s easy to ride for hours on end, aided by thick tires and cushy suspension that glided over rough Brooklyn streets.

-The Next Web

A great ebike for getting around, especially if you live in a mountain town!

I'm really impressed with this, I brought it to my gym and everyone wanted to know where they could get one!

-Engearment

find your perfect fit

One of the benefits of an ebike is that you don’t need to focus on getting the exact-right size to maximize pedaling efficiency - the motor is plenty efficient for you!

  • Stellar Series models come in two sizes that should comfortably fit most people. You'll still want to choose the one that’s best for you!
  • Utility Family models all have a lower stepover and fit most riders between 4'9" and 6'4"

We recommend you compare your inseam measurement, taken wearing shoes you are likely to ride in, to the stand-over height of our various models. As long as you've got around 1" of clearance over the top tube you'll likely be good to go! If you're on the cusp between sizes we generally recommend sizing up. Don't hesitate to reach out if you've got any sizing questions!

still need more info?

Find the full geometry for Sirius here or contact us.

Components & Specs

Enviolo hub

Way better than derailleur gearing. The Enviolo TK continuously variable transmission hub features 380% range and never needs adjustment.

Suspension fork

Our air-sprung fork has 100mm of tunable travel with a compression/lockout adjuster. 1 1/8" straight steerer and 15x100mm thru-axle

Sirius tire

27.5" x 2.1'' tire with knobby tread to tackle some light offroad riding

MPF 6C motor

We're fans of the strong and silent type, so we use an MPF mid-drive motor with all-metal gearing in an oil lube bath. It has 350-watt nominal power and 650-watt peak output.

* Mid-motor battery

375 Wh standard battery provides 15-40 miles of range depending on terrain, assist level, and other factors - an upgraded 500 Wh battery is available. All of our batteries are removable and can be charged on or off the bike.

* Class 1 or 3 controller

Our mid motor bikes can be configured with a Class 1 or Class 3 controller.

Our Class 1 controller will provide motor assistance up to 20 mph, while our Class 3 controller will provide motor assistance up to 26 mph. That's fast!

Brakes

Hydraulic brakes paired with 160mm rotors provide ample stopping power

Gates belt

Carbon reinforced belts from Gates® last longer than chains, operate quietly, and don't require grease -- no more unintentional chainring tattoos!

For Real Support

Arguably the best component: our team is here to answer even your most technical question. Get nerdy with us. 🤓

Full Specifications

Alpha Family Specs
Centauri Family Specs
Sirius Specs

FAQs

Is this a class 1 or 3 ebike?

Our mid-drive models now include BOTH the Class 1 (20mph) and Class 3 (26mph) controllers. You can install the one that's right for your riding based on where and how you ride. Check out our guide to ebike classes here to learn more.

Do your ebikes have throttles?

No, none of our first-generation bikes are equipped with a throttle. We decided to forego using throttles on our bikes due to range concerns: our 35wh/10.4 amp hour batteries work great for assisting pedaling effort though do not have enough capacity to support throttle use. 

We plan on offering a throttle on future models with larger batteries and different riding use cases (cargo & utility bikes). 

Can I put a larger battery on this ebike?

You betcha! Our mid-motor bikes can be equipped with a 500wh battery, a 30% increase over the standard 375wh battery.

Click here to see the 500wh battery.

Do your ebikes have a weight limit?

Our frameset weight limit is 440lbs but we recommend that riders over 300lbs consult with us regarding recommended modifications to ensure durability of wheels and other components. Heavier riders will likely experience less battery range since the motor will need to use more energy to assist the ebike. That's okay! We offer a variety of solutions to ensure you have a great experience on our ebikes.

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Sirius

Sirius

(12)

$2,199
$2,999 $2,199
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Our technicians take time to fully inspect and tune each bike before they leave our warehouse. Current ship time is 1 to 2 weeks from placing your order.

Every Sirius now includes both 20mph "Class 1" and 26mph "Warp Core Upgrade" controllers. 

Pictured accessories are for illustration. Fenders, racks, locks etc are available on our accessories page.


Adding bigger tires and bump-taming front suspension to a powerful mid-drive motor and reliable internal gear hub, the Sirius takes our hassle-free philosophy to the trails!

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Customer Reviews

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