How to Assemble the Biktrix Juggernaut

I've been commuting to work by bike almost every day for the past 4 months or so, and I've been loving it. Being outside makes me happy, and biking even just these 3 miles each day makes me more fit (the elevation change is significant). With fall in full swing and winter coming soon, I don't want to have to give up my bike commute when the weather turns bad. So I decided to get an electric assist fat bike. Fat wheels for the messy rain and snow, and electric assist because biking up Pittsburgh's steep hills on 26" x 4" tires could be prohibitively tough.

The Biktrix Juggernaut started as a Kickstarter project back in the Fall of 2014, and is now available for purchase from Biktrix's website. There are other electric assist fat bikes out there, but I chose the Juggernaut because the price is very competitive and the reviews have been stellar. It took a couple of weeks for the bike to arrive after I ordered it (shipping such a big package from Saskatchewan, Canada to Pittsburgh is no small feat) but the process was smooth and Roshan, who runs Biktrix, was an amazing communicator and provided great support throughout the process.

The bike comes mostly assembled, but there are a few things you have to do once it's out of the box. And since Biktrix is still a growing startup, the bike doesn't come with any instructions on how to put the thing together. I'm a handy guy, but I am still learning my way around bike repair, so I felt a bit lost at first without instructions. So I thought I'd write up some instructions based on what I figured out. Hopefully it will be useful to other people who buy this bike.


  • 5/32" (4mm) hex key
  • Additional hex key (included)
  • Wrench (included) 


  1. Install the handlebar. The bike is packaged with the front fork facing backwards, so turn the fork 180º, making sure to place the motor wires in a free position. Using a 5/32" hex key, loosen the bolts on the handlebar clamp and remove it. Seat the handlebar so that the middle of it is aligned with the middle of the stem, and replace the handlebar clamp back on the stem, bolting it in. Using the additional hex key (included), loosen the bolt on the stem's collar to adjust the tilt of the handlebar.
  2. Mount the front wheel. In the box with the charger is a quick-release rod that you will need to install in the front wheel. Unscrew the threaded cap and remove the washer and the spring closest to the threaded cap. Push the skewer rod through the left side of the wheel axle (the side with the disc brake rotor).  When it pokes through the other side of axle, replace the washer, then the spring (narrow end first), then screw the threaded cap back on, but not all the way. Lift the bike's front fork up and seat it onto the wheel, ensuring that the disc brake rotor is properly seated in the caliper. Tighten the quick-release cap and the quick-release lever.
  3. Install the pedals. On the end of the pedal thread you'll see an 'L' and 'R' for the left and right pedals. The left and right sides are relative to when you are sitting on the bike. The threads are set up in such a way that both pedals will tighten by moving the wrench (included) toward the front of the bike when the wrench is above the pedal (counterclockwise on the left, clockwise on the right).
  4. Turn the seat around and adjust it. Like the front fork, the bike is sent with its seat turned around. Disengage the quick-release lever to turn the seat around to face forward, and adjust it to the height you desire. 
  5. Turn on the motor. Press the 'M' button on the handlebar's display. Use the +/- buttons to change the level of assist.
  6. Ride your new Juggernaut off into the sunset.

NOTE: If you have purchased the optional lights, install the headlight onto the front fork using the bolt that comes with it. Attach the two loose wires on the handlebar to the light. There is no polarity in the wires so it doesn't matter which wire you connect to which terminal. Once the system is on, holding the brakes will turn the light on. To turn the light on permanently, press and hold the '+' button.