The Juggernaut Duo Series is all about flexibility. Hub-drive or mid-drive, step-over or step-thru, single battery or dual battery, entry-level or high-end. No matter your needs, there's probably a Duo for you.

Watch this video to see how The 3 Duo models stack up.


The Ultra Duo sits at the top of the Duo range, so naturally, it boasts one of the most powerful motor systems available today. The Bafang Ultra M620 mid-drive motor is loaded with 1500W of peak power and 160Nm of torque. Pair that with the 11-speed drivetrain and you'll be nearly unstoppable.

Performance. Fully Loaded.

Mid-Drive Motor

The Bafang Ultra M620 mid-drive motor features1000 watts of power and 160Nm of torque. Span cities, climb hills, and explore all the places you want to go with ease.

LCD Display

The LCD display shows all kinds of important information about your ride including speed, battery life, range, odometer, pedal assist level and more.

Thumb Throttle & Control Pad

With just a push of the thumb, you can access all of the power the motor has to offer. No need to pedal, just sit back and enjoy the ride.

Suspension Fork

The RST Guide fork provides 80mm of travel with pre-load, lockout, and rebound adjustability.


From climbing hills to holding maximum speed on the flats, the Shimano 9-speed drivetrain has you covered.

Hydraulic Disk Brakes

When it's so easy to go fast, you need strong stopping power. These hydraulic disc brakes will quickly and reliably bring you to a halt.

Integrated Front & Rear Light

The ultra bright front & rear LED lights are powered by the bike's battery and can be turned on/off with a button on the handlebar control pad.

Optional Range Extender

Multiple range-extender battery options can expand your eBike's range all the way to 100 miles. (160km on .CA site)

Rack & Fenders

These fenders will keep you and your bike clean. Need to carry some gear? Strap on the rear rack and make your way!

Technical Specifications

Size & Fittings

17" Step-Over Medium 19" Step-Over Large 21" Step-Over Extra-Large

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Customer Reviews

Based on 10 reviews
Rich Medcraft
Biktrix Juggernaut Ultra Duo 2 Step-Over

Very nice bike. Amazingly fast turnaround. Received new bike within 2 weeks. Well packaged and easy to assemble. A lot of fun!

Doug Enemark
lots of torque

This is a very nice powerful bike. I will probably replace the cassette with one thats a little more stout because of the torque this bike has. You really need to learn how to use your gears properly. Just a minor learning curve after having a hub drive before this bike. The mid drive is so much smoother than the hub drive. really loving it.

Wayne chernick
First Ebike

I had ridden one and liked it. I purchased my first Juggernaut Ultra and it is an awesome Ebike.

Michael Hildebrandt
Juggernaut Ultra Duo 2 step-over & Step Thru

My wife and I just bought the Ultra Duo 2 step-over and Step-thru and we are really pleased with these bikes thus far. We have already put on over 200km including a 100km round trip on the Lockside and Galloping Goose trails near Victoria BC. from the Schwartz bay ferry terminal.

Robert Giroux
Juggernaut Ultra Duo 2 Step-Over,Awesome bike!

Juggernaut Ultra Duo 2 Step-Over,Very easy assembly of the bike,the computer is friendly user,I am 58 years old and feel like a kid again.

david ortman

Still waiting for it to arrive

roland hanser
As advertised and expected

Easy to assemble and good communication with dedicated staff.

Luke Gebicke
Great Reliable Bike, tons of power, better than my radpower

I'll compare this bike to my only other experience with a Radpower Radwagon 4.

The biktrix is a great bike and feels better built. The 26x4 Fat tires are excellent and have lots of stability. There is some noise from the Kenda Juggernaut on the road but that's to be expected for the off road bias tire. I would like to see a more 50/50 tire balanced for more road, for me. Offroad only the tires are excellent

If I had to buy a bike again...between the Radpower and Biktrix...I'd definitely pick Biktrix.

I'm taking off one star for the only negative I have is the surprise maintenance requirement for the mid-drive motor in that it's recommend it be regreased every 1000 miles or every 6 months (I think). Often enough it's going to be common for me to perform. Unfortunately the process requires removal of the motor AND motor housing...and I find that local bike shops won't do that service due to the complexity. Something to consider that you'll have to deal with later. It would be nice if there could be a grease fitting on the motor allowing for easy application or an easier removal process for getting to the motor gears for cleaning and regreasing.

Biktrix support does have a video detailing the regreasing process but it's oddly voiced and again probably more complex than most bike owners (and bike shops) will do.

Patrick Hawthorne
Fun bike… once you fix some things.

I will preface everything I say her by saying that your experience may differ from mine. However, for a bike I spent over $4k on, I will say I expected a little more. I get that the motor and battery are a very large part of that cost, but some things were frustrating about my initial experience. I will also say that if you are using this primarily on a paved road and using an assist level above 1 or 2, you may not have these issues. That said, I’m also not a hardcore mountain biker out there tackling black Diamond trails.

My first issue I had was that there were no instructions with the packaging the bike came in, and the Biktrix website/YouTube channel had no directions for the Juggernaut Ultra Duo 2, only the 3. Now, they are similar, but not exactly. So, it was slightly frustrating.

Secondly, I got the bike put together and took it out for a brief test ride to make sure everything was where it should be. The shifting felt weird, got back to the house, and the chain was was as dry as the Arizona desert. No lube, at all. First time I received a bike that didn’t have the chain lubed. I lubed it up, and it was fine. Until I got out on a trail.

First trail ride I had was not fun. The very low end Shimano derailleur on this bike could not handle a moderate mtn bike trail. I had issues with it shifting, especially gears 5-9. And the chain would jump at times when I was pedaling up a steep hill with a lot of tension on it. Not fun, especially with a nearly 90lb bike that you’re trying to maintain balance on.

To summarize my complaints, I’ve changed the whole drivetrain to a Microshift system. Microshift have fairly reasonable priced components that are designed for e-bikes. Biktrix should look into using them instead of Shimano and SRAM that charge way too much for their medium/high end components that actually work. They aren’t the name that Shimano and SRAM are, but they are way better than the bottom of the barrel components those companies shamefully sell. The brakes are serviceable for now, but I will probably change those down the road, too.

With 90% of my complaining out of the way, this bike is a lot of fun once you make it yours. I have done 60 mile rides that are mostly paved, and had a blast. I have done 10-15 mile mtn bike trails, and had a blast. I moved from coastal California that was mostly flat, to central Arizona that is a mile up and can be very hilly. I am older now and not in the same shape that I was 10-15 years ago when I was riding 150-200 miles/week plus a mtn bike day on the weekend. I typically leave the assist level at 1 on inclines just to give me that little help, and 0 when on a downhill or flat ground. People who say you don’t get a workout on an e-bike are wrong. I plan on doing the Solvang century ride in March, and I cannot wait to see how far I can push this bike and it’s batteries, and hopefully not literally.

Last recommendation: change the tires to the Vee Tire Speedsters, if you’re not doing loose dirt mountain biking. I got a flat on my second trail ride, so I changed the tires and also used FlatOut tire sealant. I (fingers crossed) haven’t had any issues, yet. These tires are also much quieter than the provided tires, and more resilient to puncture.