Pay in installments of $7.47 with
,
and
Shipping Estimate
USA
- USA
- CAN
- USA
- CAN
Ships within 48 hours · Estimated delivery Sep 29 - Oct 4
Promo Codes Available:
For Your Every Summer RSVP, with Code: SUMMER15
Description
e bike fatbike fully ELECTRIC FAT TIRE E-BIKEIntroducing the all new Keystone Electric Fat Tire Bike. Since 2013, Borealis has specialized in lightweight, high end fat bikes. The Keystone is our first ever Class I electric bike. The frame geometry is optimized for riding just about anything with clearance for up to 5 wide tires. Paired with the most technically advanced components in the industry, the Keystone sets the standard for premium quality Electric fat bikes. HIGHLIGHTS Color: Gunmetal
Introducing the all-new Keystone Electric Fat Tire Bike. Since 2013, Borealis has specialized in lightweight, high end fat bikes. The Keystone is our first ever Class I electric bike. The frame geometry is optimized for riding just about anything with clearance for up to 5” wide tires. Paired with the most technically advanced components in the industry, the Keystone sets the standard for premium quality Electric fat bikes.
HIGHLIGHTS
- Color: Gunmetal Grey with Cobalt Blue Graphics
- Weight: 56 lbs. as shown.
- Standard features include Shimano EP8 Drive Unit, Shimano 630Wh Battery, SRAM G2 RS brakes, Mastodon Pro EXT 120mm suspension fork, carbon handlebars, dropper seat post, durable Sun Ringle Mulefüt rims and your choice of tires.
- Frame geometry provides responsive handling, offering maximum control for varying conditions in snow or sand.
- Tire clearance up to 26x5” and 27.5x4.5”.
- Lightweight, 6000 series aluminum frame comes with internally routed cables, 1-2 bottle cage mounts and lizard skin protection.
- Keystone Frames are backed by our LIMITED LIFETIME WARRANTY.
ASSEMBLY
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. A kit will be included with your order that has all the necessary tools assemble your bike, including a multi-tool, torque wrench, and shock pump. If you are not familiar with this level of assembly, we recommend having your local bike shop complete the assembly.
Stay tuned for our step-by-step assembly video.
WHEELS AND TIRES
- All bikes come standard with tubes.
- If you order rim tape with your Mulefut rims, we will tape the rims and install the tires with tubes.
- Tubes must be removed and tubeless valves installed for tubeless set up. We recommended to have this completed by a professional bicycle mechanic.
SIZE CHART
BUILD SPECS
| 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 |
| 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 | Your choice of SunRingle Mulefüt SL - 26x80, 27.5x80, or 27.5x65 |
| Spokes | Straight Gauge 2.0 Black |
| Hubs | Borealis Gen 4 15x150 / 12x197 |
| Tires | Your choice. All tire options are listed online. |
| 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. |
FRAME SPECS
| 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 |
GEOMETRY CHART
| 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 |
FAQ:
| 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. |
Shipping Notes
- Free Standard Shipping on $100+ Orders to the USA.
- Except Preorder products are shipped in 48 hours.
- Delivery to the USA:
- Standard Shipping : 3-10 business days
- If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
- We offer a 30-day return/exchange service after receiving.
- Final sale items are not eligible for returns or exchanges.
- To process your return/exchange, please contact us at [email protected]
- Please click here for more details>>> Return & Exchange Policy
4.8 ★★★★★
Based on 11 reviews
Sort
Product Reviews
★★★★★ 5
Great Banana Plugs!
Size: 6 Pairs / 12 pcs
These FosPower banana plugs work very well. I have used dozens of these great FosPower banana plugs over the years, and they definitely work as advertised. When comparing apples to apples (or bananas in this case....lol), all Banana plugs work virtually the same way, and these banana plugs are no different. Strip speaker wire, unscrew banana plug cover, loosen speaker wire retaining screw(s), insert speaker wire, tighten speaker wire retaining screw(s), screw on banana plug cover, and wallah, a secure/conductive speaker/amplifier wire connector is created. Albeit, some banana plugs require the speaker wire to be splayed over a hollow post, and then they are held down by a screw-on retainer/cover. However, I much prefer these FosPower dual retaining screw type of banana plugs for their speaker wire holding ability.
I always use high quality 14 gauge OFC speaker wire with these FosPower banana plugs, and they work perfectly together. I have used these FosPower banana plugs with many different speaker and amplifier brands over the years, including Klipsch, Pioneer, Polk, Denon, Dayton Audio, and Fosi with no problems at all. They just work, and work well. I have never had a FosPower banana plug break, release the speaker wire or short out, in all of the years that I have used them.
Yes, these FosPower banana plugs do fit rather tightly into the connectors, at first, on a lot of speaker and amplifier brands/models. However, after the initial "squeeze" the banana plugs will lossen up, and become easier to install and remove. However, they still retain their great holding ability even after the initial squeeze. In order to overcome this initial "tightness," I usually just stick the FosPower banana plugs into a connector of an old portable amplifier, before assembling them, in order to squeeze them before inserting them into their final speaker or amplifier destinations. This is especially useful when working in tight places, where there is not much room to work in order to push the FosPower banana plugs into their tight connections firmly.
Overall, I highly recommend these FosPower banana plugs. I am currently using them all over the house and shop for home theater and music listening (and testing projects). Just be aware of the tight fit in some speakers and amplifiers. Also, the 2 very tiny speaker wire retaining screws can be a challenge sometimes. Just use a good standard blade jewelers screwdriver, and be careful not to remove the retaining screws all of the way or over-tighten them. Once these things are mastered, using these FosPower banana plugs becomes second nature. Have fun!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on August 28, 2024
★★★★★ 5
Great Product
Size: 6 Pairs / 12 pcs
These banana plugs have worked perfectly, no matter what gauge I have run in them, they work great. Easy assembly and great quality.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 8, 2026
★★★★★ 4
The most legit banana plugs I could find on Amazon
Size: 6 Pairs / 12 pcs, Size: 6 Pairs / 12 pcs
NEW PREFACE:: I am kind of glad I first bought the horribly magnetic, horribly made and GOLD PAINTED Sewell crimp on plugs (some reviewers say that Sewell are better and easier to use than the FosPower, which is true in design, but in quality of materials FosPower beats them hands down!!) ... Changing from those to these FosPower plugs plus the Monoprice 90° plugs, I am flabbergasted at the difference they make in sound quality. I have heard people say that they can hear the difference and even as an audiophile I was skeptical..... but my skepticism has been completely erased by what I am hearing with my own ears. I waited a few days to make sure I wasn’t just tripping before updating this review 🤣....but it has become clear to me how much a difference plugs made from the right materials actually make!!! I am 100% serious that the bass coming out of my Polk Signature Series tower speakers has at least doubled at the same volume. I can also now turn the volume up Way past my max volume before, without any distortion and much more clarity and less harsh highs. Everything just sounds warmer in general now which is amazing!!!! This is dangerous info for me... because now I’m thinking about making some really nice custom wires to see how much of a difference that makes 🙄🙄🤣 OK onto the review of the actual plugs here~~
These seem like decent connectors. I can’t tell if they are brass or copper, but they only have a slight hint of a magnetic property when testing them with a very powerful magnet. I was easily able to fit x2 - 14ga wires into it for bi-wiring purposes, including screwing on the collar. (As seen in my example pic) The gold plating on the tips seems legit and not painted like some of the plugs from Sewell... I have tested and tried quite a few plugs from Amazon and most seem to be crap. These however hold up better than most! These and the Monoprice 90° banana plugs with the black and red rubber sleeves. The latter are gold plated copper and have zero magnetic properties. (if you need 90° banana plugs)
UPDATE: still the best plugs I have found, but upon full install found two issues. One is a defect where a set of the plug threads for the barrel cover body weren’t cut right. The body’s do not tighten and stay loose because of that. Obvious issue for vibration with metal on metal...
The other issue is that even though these say they can fit different gauge wires, they seem to be geared more towards 12 or 10 gauge. I am using semi solid strand 14 gauge and find that unless I fold the wire over to make it double thick, the bolts use up all the thread and seem to become kind of loose inside the body. They won’t fully seat and keep spinning no matter how much you tighten. They seem to stay secure still but I just wonder about longevity over time with vibrations. So I just doubled up the wire and they seated fine! Not the worst issue in the world, but just kind of a pain since you have to strip the wire longer than you normally would so you can fold it over.
ANOTHER UPDATE: I had to remove these plugs from the wire to connect them to a crappy spring terminal amp while my better amp was in the shop. The issue I wrote about with the set screws "bottoming out" on smaller gauge wire became a more pronounced issue! I could not unscrew the set screws anymore and just had to cut the wires... So that means I will need to purchase more of these to replace the ones I cannot get wire back into. Not the best design, but still one of the best plugs I have found on Amazon.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 26, 2021
★★★★★ 5
Sturdy. Tight fit. No wobble
Size: 2 Pairs / 4 pcs
These are the best ones I’ve found. This order will connect one wire. Luckily that’s what I needed. If you’re doing more than one wire…
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 18, 2026
★★★★★ 5
Superior Design!
Size: 6 Pairs / 12 pcs
Delivery was lightning fast.
I tried a pack of two pairs of these banana jacks as a sample to see if these would meet my needs. The design of these plugs is superior. The design was exactly what I wanted because the speaker wire is secured with TWO set screws. Then I ordered an additional six pairs of plugs to hook up my subwoofer to my amp and speakers.
(I feed the audio output from the amp to the sub. The sub has a crossover that keeps the low frequencies and sends the mid and treble frequencies to my bookshelf speakers.)
I love the security of two set screws on each plug and love the barrel that screws on AFTER the wire is secured by the set screws. Most banana plugs have a hole through the shaft of the plug that receives the stripped wire. Then the barrel cover is screwed down to secure the wire in the plug. This design compresses the speaker wire but eventually the cap loses it grip and allows the connection between the wire and the plug to become loose. Then the transfer of the audio signal becomes poor and the speakers sound bad. Every month or two I needed to check all the banana plugs and re-tighten many of them for the best performance. The two set screws eliminate this problem. The set screws are quite small and take a little extra care in installation. You will need a small flat blade screwdriver to tighten them. I used the 1/8" flat blade driver from a set of jewelers screwdrivers.
These well made plugs are a bit pricier that many of the banana plugs available but certainly not the priciest plugs available. For me, the slightly higher price was more than offset by the security of the wire within the plug.
I'm not thrilled with the extra tight fit of the tip on the plugs into the jacks. It took a lot of effort to insert the in the jack. Actually I "greased" the pins (very sparingly) with with non-corrosion, conductive paste (Ox-Gard, No-Corrode, etc. Do NOT use any other grease.) Next time I'll use pliers to compress the pin.
My only quibbles are that the spring pins that go into the jack are very tight and that the plugs are only sold in quantities of two pairs or 12 pairs.
I recommend these banana plugs for all who are using the banana plugs and jacks for hooking up your speakers. It's a very convenient way of connecting speakers if your speakers and amplifier have the banana jack as part of the binding post. Further, it's much safer to use banana plugs since the possibility of shorting your amplifier with a stray strand of wire is practically zero. Easy Five Stars.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 13, 2018