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Keystone Electric Fat Bike - Medium Gray & Blue (ID 19760)

Independence Day SALE - 20% OFF COMPLETE BIKES & FRAMES ENDS 7/15 - Discount automatically applied in cart!

0% APR up to 24 months with Affirm! Financing Options Available at Checkout.

$3,900.00 USD

Size Chart

bike size chart

Shipping and Returns

PO boxes not accepted.Shipping discounts or exclusions only apply within the lower 48 states of the US. Contact us if damage occurs during shipping. 

Borealis offers a 30-day money-back guarantee. If you are unsatisfied with your purchase for any reason, you can exchange your product or return it for a full refund minus any associated transaction fees and shipping costs. Customer is responsible for return shipping costs. Returned and exchanged items must be in sellable condition.




Original Owner
BOREALIS offers a LIMITED LIFETIME warranty to the original owner of each new BOREALIS bicycle, fork or frameset that the bicycle frame, fork or frameset when new is free of defective materials and workmanship.

Normal Conditions
The limited warranty is conditioned upon the bicycle being operated under normal conditions and use, and properly maintained.

This limited warranty does not apply to paint/finish or components attached to the bicycle/fork/frameset such as rims, drive train, brakes, seat post, handlebar and stem, or any suspension related parts or components.

Paint/finish, components attached to the bicycle/frameset such as rims, drive train, brakes, seat post, handlebar and stem, or any suspension-related parts or components are covered under the limited one (1) year warranty.

Load Weight
The total cargo load for BOREALIS frames and forks is 300 pounds. The total cargo load includes the rider and any associated gear warn by the rider or attached to the frame or fork.


Subject to the following limitations, terms and conditions, BOREALIS warrants to the original owner of each new BOREALIS bicycle that this bicycle, when new, is free of defective materials and workmanship. This warranty shall expire one (1) year from the date of the original purchase from an authorized BOREALIS dealer and is conditioned upon the bicycle being operated under normal conditions and use, and properly maintained. This warranty is void if the bicycle was not purchased new or not properly assembled by an authorized BOREALIS dealer.
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Customer Reviews

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Frame Borealis Keystone Aluminum 15", 17", 19", 21"
Drive Unit Shimano DU-EP800
Battery Shimano BT-E8036 (630Wh)
Display Shimano SC-EM800
Assist Switch Shimano SW-EM800L
Speed Sensor Shimano EWSS300L540A
Fork Manitou Mastodon PRO EXT 120mm, 51mm offset
Headset FSA w/ Star Nut
Stem Borealis 50mm or 70mm (Based on Supply)
Handlebar Borealis Carbon 
Grips Ergon GP1
Saddle WTB Volt Medium Steel
Seat Collar Borealis Bolt-On
Seatpost KS Lev Integra 125mm (SM, MD) / 150mm (LG, XL)
Brakes SRAM G2 RS
Rotors SRAM HS2 200mm front / 180mm rear
Shifter SRAM AXS Pod Contoller Right Bridge w/ MMX Clamp for GX Eagle Transmission
Derailleur SRAM GX Eagle Transmission Derailleur
Cassette SRAM GX Eagle Transmission Cassette 10-52T
Chain SRAM GX Eagle Transmission Flattop Chain
Crank Arms Samox 170mm
Chainring Mount Samox 104 BCD for 75mm chainline 
Chainring SRAM Eagle Transmission E-Bike MTB Chainring 104 BCD 36T Steel 
Rims Mulefüt SL - 26x80
Spokes Straight Gauge 2.0 Black
Hubs Borealis Gen 4 15x150 / 12x197
Tires  Terrene Cake Eater 4.0" Light 120 TPI
Included Shimano ECE80042 Battery Charger, AXS Power Pack, Kickstand, UDH Hanger, Key for battery release, Borealis Rear Thru Axle, Remote Battery Charging Adapter
Weight Size Medium w/ Mulefut 27.5x80 & Terrene Yippee Ki Yay 4.3" Tires: 56 lbs.

Wheel / Tire Size 26 x 3.8–5.0" on up to a 100mm rim / 27.5 x 2.8-4.5 on up to a 82mm rim / 29 x 2.25–3.0
Susp Fork Travel 120mm
Fork Offset 51mm
Headset-Upper IS41
Headset-Lower IS52
Seatpost ø31.6mm
Seat Collar ø34.9mm
Dropper Compatible Internal - 125mm for SM & MD / 150mm for LG & XL
Front Derailleur Type Not Compatible
Bottom Bracket Shimano EP8
Crankset (Max Ring) Chainline 75mm / 1x (38t)
Rear Brake (Rotor) 74mm post (160–180mm)
Rear Spacing 197 x 12mm thru-axle
Rear Axle ø12 x 222L, TP= 1.0, TL = 16
Derailleur Hanger SRAM UDH
Bottle Mount  Small & Medium: 1 (downtube) / Large & XL: 2 (downtube & seatube)
Rear Rack Reccomendation Old Man Mountain Divide Fat 
Rear Rack Mounts, Upper Yes
Axle to Crown 531mm
Steerer Tube Size 28.6mm
Steerer Style Tapered
Crown Seat Diameter 40mm

Small 15" Medium 17" Large 19" X-Large 21"
Effective Top Tube 630 645 660 665
Seat Tube Center to Top 381 432 482 533
Head Tube Length 160 160 175 190
Head Tube Angle 69° 69° 69° 69°
Seat Tube Angle 73° 73° 73° 73°
Chainstay Length 480 480 480 480
BB Drop 60 60 60 60
Reach 420 435 445 446
Stack 688 688 702 716
Standover Height varies based on wheel and tire size
Wheelbase 1187 1207 1223 1229
Fork Offset 51 51 51 51

Asssembly Video

Some assembly required upon receipt. Your bike will be completely assembled and tuned by Borealis, then partially disassembled for shipment. The remaining assembly will require installation of the rear derailleur, chain, fork, seat post, wheels, and handlebars.  If you are not familiar with this level of assembly, we recommend having your local bike shop complete the assembly. 


Can I use the Keystone in cold temperatures?  It is okay to use your Keystone in the operating temperature range, suggest by Shimano: -10 - 50°C
How do I remove the battery? Each Keystone will come with a set of keys. Make sure to save your spare key and safe location. Insert the key fully into the lock cylinder on the non drive side of the downtube until it stops.  Rotate the key clockwise until the battery drops from the downtube providing access to the latch release mechanism. Use your index finger to gently depress the spring which will fully release the battery. Use caution to support the battery when removing it so it does not fall to the ground. 
How can I file a warranty claim for the drive unit and other electronic components?  Contact an authorized Shimano STEPS dealer.
Can I change my motor/power settings?  Yes, you can customize your motor settings via the app as well as update the firmware. You'll need to download the Shimano E-tube mobile app.
Can I change the max speed?  No. Depending on where you've purchased your Keystone it will either have a max assist speed of 20mph or 25km/h. This setting cannot be modified by the user or a dealer.
Can I purchase an extra battery? Yes, you can purchase a spare battery kit with a spare downtube cover directly from Borealis. Spare battery kits may not be available in all markets. You can also purchase a spare battery from Shimano, but it will not include a battery cover.
Can I ride the Keystone without the battery? No. This will void your warranty with Shimano and cause damage to the motor system.
Do I need to update the firmware / software?  Firmware can be updated via the Shimano E-tube mobile app.
How do I use walk mode?  Hold the upper button (down assistance level) for 1 second until the display turns blue and displays WALK mode. Press and hold the same button to power the rear wheel. 
How long does it take to charge the Shimano 630Wh Battery?  With the included EC-E8004 charger, the battery can fully charge in 6 hours.
How long will my battery last? The remaining battery capacity is affected by temperature and cycle count. Generally, it decreases approximately 5% a year. This means roughly 95% capacity remains after 1 year, and 90% after 2 years.
How should I store my bike and or battery?  Charge your battery to approximately 70% before storing for long periods of time. Store in a cool, indoor location with a stable temperature between approximately 10 - 20 C / 50 - 70 F. No direct exposure to sunlight or rain.
Are the electronic components waterproof?  Yes, the STEPS system is waterproof as long as all components of the system, including the battery and battery cover, are installed correctly. We recommend not using a high-pressure washer to clean your Repeater, but riding in the rain and regular cleaning are okay.
My bike won't turn on, what do I do?  First, make sure all cables are plugged in, if they are then try removing and reinstalling the battery. If it still won't turn on try charging your bike for a few hours. If your bike is too hot or too cold, it might not turn on. If your bike still does not turn on, contact a Transition or Shimano dealer for support.
Should I only charge my battery when it's completely drained?  No, simply charge the battery any time you need it, frequent charges actually help battery longevity. Avoid letting the battery discharge completely. Charge to 70% before storing for long periods.
What are the different error codes and what do they mean?  Whenever you encounter an error code, first cycle the power off and then back on. If the code persists, remove the battery and then reinstall, which will hard reset the system. If neither of these steps resolves the issue, please reference the Shimano error code list. If you cannot resolve your error code via your Etube mobile app please visit your nearest Shimano STEPS dealer or contact Shimano STEPS customer support.
What is the range and how can I maximize it?  There are many factors that affect battery range, such as, how much effort the rider is providing, the gradient of terrain, ambient temperature, and rider weight. The best way to maximize your range it to spend more time in Eco and Trail modes, and minimize the amount of time spent in Boost mode.
What is the widest tire the Keystone can fit?  26x5.0" or 27.5x4.5"
What kind of maintenance is needed on the drive unit and how often?  The drive unit is sealed and cannot be serviced. If there are any issues with the drive unit, it will need to be removed and sent back to Shimano for service or replacement. The drive unit along with the battery is designed to last over 1000 charge cycles. Assuming you're getting 30 miles (48Km) per charge, the drive unit should last 30,000 miles, or much longer than pretty much any other part on your bike.
Why does my bike stop giving assistance over a certain speed?  Depending on where you've purchased your Keystone it will either have a max assist speed of 20mph or 25km/h. This setting cannot be modified by the user or a dealer.
Will environmental temperature affect battery life?  The battery life will be shorter during cold temperatures, this is not a sign of a problem.
Will my bike be delivered with a charged battery?  Your Keystone was shipped in a "sleep" mode with the battery at approximately 30% charge. It is recommended to fully charge your battery before the first ride.


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