GreenBike Big Dog Extreme 750W Folding Fat Tire Electric Bike

8 reviews

FREE Shipping to US Lower 48
DAILY Inventory Updates
NEED HELP? Call 888-883-3350

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Black with Red and Silver
Black with Red and Gold
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Hydraulic Disc Brakes w/ Auto Motor Inhibitors

High-Torque 750W Rear Hub Motor

Pedal Assist & Thumb Throttle

Long-Range Battery

greenbike electric motion dealer authorized logo for really good ebikes


Big Dog Extreme Description

If you're looking for an affordable fat folding ebike with full suspension, the Big Dog Extreme might be the perfect fit. It's got tons of power, premium components throughout, and incredible build quality.

The Big Dog Extreme can handle riders up to 6'-5" and 250 Lbs., so it's a perfect off-road ebike for the outdoor adventurer. The 750W rear hub motor will power you up steep hills, and the 48V/15Ah battery will extend your range with each charge.

Big Dog Extreme Specifications

  • Use Case: Urban Jungles, Remote Trails, Sunny Beaches
  • Frame: 6061 Aluminum Alloy Foldable Full-Suspension Frame w/ Adjustable Stem Height
  • Fork: Mozo USA Suspension Fork w/ 140mm Travel
  • Motor: 750W (1200W Peak) Rear Hub Geared Motor by 8Fun (a Bafang brand) w/ 80Nm of Torque 
  • Drive Modes: Speed (Cadence) Sensor Pedal Assist System w/ 5 Levels of Assist, Right-Side Thumb Throttle, 6-Speed Shimano Gearing
  • Removable Battery: Easy-Access 48V/15Ah Li-Ion Battery w/ Boston Power Cells (for estimate range per charge, please refer to our Ebike Range Calculator)
  • Charge Time: 5-6 Hours
  • Brakes: Hydraulic Disc Brakes w/ 160mm Rotors & Automatic Motor Inhibitors
  • Tires: 20" x 4" Fat Tires by Innova
  • Seat Post: Suspension Seat Post w/ 27.2mm Travel
  • Saddle: Wide Saddle
  • Display: LCD-5900 Ebike Intelligent Display w/ Battery Level, Speed, Assist Level, Odometer and Trip Distance Readouts
  • Folded Dimensions: (L x W x H) 37" x 18" x 33"
  • Crank: 170mm w/ 28-33-42T
  • Step Over Height: 25"
  • Minimum Seat Height: 33"
  • Reach: 18"
  • Handlebar Height: 42" (from the ground)
  • Recommended Rider Height: 5'-2"+
  • Bike Weight w/ Battery: 61 Lbs.
  • Max Load Capacity: 300 Lbs.
  • Box Dimensions & Weight: 38" x 18" x 29" (88 Lbs.)
  • Warranty: 1 Year
  • Lights: Battery Operated Front and Rear LED Lights
  • Assembly: The Big Dog Extreme comes mostly assembled. Final assembly includes attachment of the Seat Post and Handlebar. Please see the assembly video below.
  • Tools Required: 6mm Allen Wrench (Included)
  • Shipping: Free shipping to the lower 48. We are unable to ship this brand to Alaska, Hawaii or Canada at this time.

Directions to Unlocking the Big Dog Extreme Speed Limit

  • Make sure the display is off
  • Hold both breaks and throttle all the way down
  • Using another finger (while still holding) turn on the display by pressing down the M button
  • After the display turns on, keep holding the breaks and throttle for 16 seconds
  • After 16 seconds, let go
  • After letting go change the pedal assist level to 5 and pedal
  • If you see that the speed gets to around 27-28 mph, it is unlocked
  • Repeat steps if it doesn’t work 

Electrified Reviews

We love it when an independent ebike reviewer covers one of the bikes we carry. Check out the review of the Extreme by our friend Brent McCluskey from Electrified Reviews. Brent says:

"This is a folder with some attitude, and honestly, it’s just a great ride all around. We’ve reviewed quite a few electric bikes from Green Bike and this company does an excellent job at picking and choosing the right components. And the Big Dog Extreme is no exception. This folding electric bike is powerful, fast, compact and perhaps most importantly, it’s comfy." Not bad!

Here's a video of the ebike being unpacked and assembled. Super easy.


Here's a video showing how to fold and unfold your electric folding ebike. Awesome.

Here's a video showing how to get set for a perfect ebike ride. Be safe out there.


Orders for in-stock items take 24-48 hours to process, then about 5-7 days in transit. Delays due to Covid have occurred. If an item is on backorder, the estimated ship date will be shown below the Pre-Order Button.

All products are shipped free within the Contiguous US via UPS, FedEx or similar carrier. Shipping to AK, HI and PR may incur additional charges.

If your package appears damaged from shipping, please do not accept it. Tell the driver to keep the package and contact us immediately at 888-883-3350. We offerGuide Package Protectionto ensure against lost, stolen or damaged goods. Click here to learn more about Guide.

Returns for buyer’s remorse are typically not accepted by our suppliers, and if accepted, the customer may incur shipping and restocking fees.

Please click here to read our entire Shipping & Returns Policy.


Ask a Question
  • Hi I just bought a Big Dog extreme from your store, I am 6'4" and need a longer seat post. My knees are really close to the handle bars as well... I have the handle bars as high as they will go... Do you have any suggestions? Ted.

    Thank you for your recent purchase. There are a number of long seat posts that can fit the Extreme, just make sure to select the 30.4mm diameter post. Here is an example of a product that would fit:

  • What is the step over height


Customer Reviews
5.0 Based on 8 Reviews
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Filter Reviews:

    Electric bike arrived, electric trike ordered too.

    Outstanding bike. We've already order a electric trike for my wife also, waiting for it to arrive. Great service. Ya got my business.

    Chuck M.
    United States United States

    Help, I am addicted!

    WOW, I did all my research and limited my search to TWO different brands of folding ebikes for my Geocaching adventures. At least I thought I had it down to two models, till I fortunately stumbled upon the GreenBike Big Dog Extreme information. Now, I see this is the lightest model between all three, more power than the other two, more free accessories and still within my price points. I will try something really silly and email this company on July 5th, surely they wont respond. Ooops, bad call, not only did Steve respond, he answered my question, conquered my objections and I bought a new Ebike. This company is amazing so far, hopefully, they will continue going above and beyond with sales and constumer service.

    Theodore F.
    United States United States

    Perfect Fit

    I was in need of a nice folder that I could keep in my trunk and I stumbled upon this Big Dog Extreme from Really Good Ebikes and it turned out to be perfect for my outdoor needs. This ebike ticks off everything on my list and the long-range battery is a big plus.

    Kevin S.
    Dominica Dominica

    Really Good Ebikes

    Thanks for the review.


    Awesome Ebike

    I just received my new Big Dog Extreme from Greenbike and I have to say, so far it does seem live up to its name. The first thing I noticed was the power on this bike, and I can't wait to get on some trails with this Dog.

    Greg S.
    Dominica Dominica

    Really Good Ebikes

    Thanks Greg.


    Fat Folder w/ Tons of Torque

    The Big Dog is a great fat tire folding ebike for the off road. Its motor is very powerful, and I felt like the fat tires gripped the trail well. Thanks.

    Garth L.
    United States United States

    Really Good Ebikes

    Thank you Garth.