Big Sur 26" Ebike


Big Sur is a 26 x 4” fat tire all-terrain e-bike, equipped with a powerful 750W Bafang rear hub motor. Big Sur is Class 2/3, meaning it'll take you up to 20mph using the throttle, and 28mph while pedaling. A specially-designed big headlight, extra-large 203mm brake rotors, LG 21700 battery cells, and a full UL2849 certification make Big Sur one of the safest e-bikes on the market. Sporting a bigger 52T crankset for stability at speed and a custom AIMA Comfort XL seat, Big Sur provides riders with a remarkably comfortable and smooth riding experience.

Technical Specifications


Big Sur


750W (Rated) / 1200W (Peak) , 48V Brushless Rear Hub Motor


Throttle on Demand


Color LCD, Smart Easy-to-Read Display with Backlight


Up to 28 MPH Pedal Assist, 20 MPH Throttle Only


Removable Internal Lithium-ion 48V, 15Ah (720Wh) with LG M50LT 21700 cells




Torque Sensor


5 Levels


48V 3 Amp Fast Charger, about 5 Hours to a Full Charge


30 to 60 Miles


6061 Single-Butted Aluminum Alloy Frame with Internal Battery


82 lbs. ( Battery included)


9/16' Alloy Platform


Suspension Fork with 80mm travel, with lockout


400 lbs.


Included, Aluminum Alloy Kickstand 


170mm w/ 52T


Shimano 8 Speed




Tektro Hydraulic Disc Brakes


203 mm


130 Link, 8 Speed


Double Wall Aluminum Alloy


Black Stainless 12G Front / 12G Rear


Butyl Rubber


Front Aluminum Alloy Disc Hub 


26" x 4" Puncture Resistant


AIMA Comfort, 280mm*270mm Saddle


Aluminum Alloy, 30.4mm 2-Bolt Clamp


Threadless, 31.8mm, 7 Degree Rise, Ext 75mm


34.9 mm Quick Release


Aluminum Alloy Double Wall, 31.8mm, 680mm


Sealed Bearing Headset


Ergonomic Comfort

*Ebike Range: Explained

An e-bike's battery life is influenced by several factors that can affect its maximum range. While our e-bikes can achieve up to 60 miles of range under ideal riding conditions, range figures can drop below 40 or even 30 miles without keeping these factors in mind. Here's a list of the most common factors that affect range, as well as what you can do to maximize your riding time.

  • Pedal Assist: Higher levels of pedal assist will allow for an easier ride, but will also draw more power from the battery. Lower assist levels are better for getting as many miles as possible out of your battery.

  • Average Cruising Speed: Riding slower will decrease the amount of energy you lose to wind resistance as the bike pushes you forwards through the air. Slower speeds will extend battery life.

  • Tire Pressure: Fat tire bikes like Big Sur and Big Sur Sport can have their tires aired down beneath the pressure rating listed on the tire for better off-road performance, but this will lead to a increase in rolling resistance, and running too low of a pressure could raise your chances of a tube failure. For most riding situations, pumping up your tires every week or two to the recommended pressure shown on the side of the tire will keep your ride safe and energy-efficient.

  • Load Weight: This includes both the rider's weight and the weight of any cargo you may be carrying. More weight will take more time and energy to get up to speed, negatively affecting your range. It's best to keep loads light whenever possible if you're looking to extend your range.

  • Terrain & Elevation: In general, riding over smooth terrain with few to no changes in elevation will give you a longer range. Hills and rough terrain can greatly impact your maximum range, especially on higher assist levels.

  • Wind: Wind resistance is generated as you ride through the air, but it can also be generated by, well, the wind! Riding in heavy winds, especially if it's a constant headwind, will lead to a decrease in range. However, if you can catch a tailwind, you may actually be able to steal a bit of range back, as the wind would be traveling in the same direction as you are, effectively cancelling out any wind resistance you would generate on your own.

  • Ambient Temperature: Riding in cold weather will impact the battery's ability to function optimally, sometimes a lot more than you might think. This is a limitation imposed by the chemistry that allows our current battery tech to work. A good rule of thumb is, if you're comfortable (temperature-wise), then the battery is comfortable too. This also goes for storing the battery if you won't be riding for an extended period of time, which leads to:

  • Battery Condition, Care, & Storage: As you use your e-bike's battery, its effective range will diminish over time. This is again a consequence of the Li-ion technology that powers many of our devices today, including mobile phones, laptops, electric cars, and of course, e-bikes. Li-ion batteries traditionally experience a noticeable drop in total capacity after several years of continuous use, which isn't a concern for brand-new e-bikes, but it's something to keep in mind as your e-bike ages. The battery cells that make up an e-bike battery pack like to be kept between 20% and 80% charge, and keeping the battery in this range as best as you can will prolong the battery's total lifespan.

    However, if you ride frequently and/or if you ride long distances, charging to 100% is still more than safe. The Bafang battery that our bikes utilize will automatically stop charging at less than 4.2V per cell, greatly reducing the usual wear caused by fully charging the battery pack. Think of this feature as an extra level of battery capacity protection that prevents each individual cell in the battery pack from reaching its own max charge level. This means that in exchange for less than 5% of the pack's total range potential, you'll be able to retain more total battery capacity for longer compared to if the battery cells were allowed to reach their absolute maximum charge levels every time.

    This practice is already commonplace in the EV industry, and it's finding its way into the PEV (personal electric vehicle) industry in e-bikes, e-scooters, and many more e-things because of the huge increase in battery lifespan it provides. Traditionally, Li-ion batteries can lose up to ~20% capacity after several years of continuous use, but this technique of limiting the battery's max charge level aims to bring that percentage down considerably.

    Additionally, as mentioned above, if you'll be storing your bike without riding it for a long time (more than a month), it's best to remove the battery and keep it inside as opposed to in a garage or attic, where temperatures can fluctuate much more than what you'd see inside. If you're going to store your battery, try to charge (or discharge) it to as close to 50% charge as possible first, which is where the battery likes to sit if it won't be used for a while. Keeping the battery near 50% will minimize the degradation it undergoes during storage.
Your Safer electric bike choice

Fully UL2849 Certified

Geometry and Fit


Hub Motor and Battery

Powered by a 48V 15Ah battery using LG high-capacity cells, Big Sur's 750W Bafang rear hub motor has the juice to take you just about anywhere.

Torque Sensor

One of the latest e-bike innovations, a torque sensor sees how hard you pedal in real time and matches your input power using the motor. This leads to a safer and more intuitive ride, as well as conserving battery life.

Full Color Backlit LCD Display

View essential stats at any time with a bright and daylight-ready full color screen. Choose between several different themes to see your speed, battery life, pedal assist level, and much more.

26” x 4” Fat Tire

Big Sur's puncture-resistant 26" x 4" tires can handle almost any terrain, giving you the confidence you need to push your own riding limits off-road.

Suspension Fork

With up to 80mm of travel and adjustable preload and lockout settings, our suspension fork eats up everything in your path, assisted by Big Sur's 4" wide tires.

Fender & Rear Rack

An MIK HD rear rack comes standard, allowing for endless customization possibilities. Plus, fenders come pre-installed to ensure you're protected from below while riding in any weather conditions.

Flat Position Welding

We've taken great care and utilized some of the newest aluminum welding techniques available on our frame, which comes with a lifetime warranty. These techniques allow the frame to maintain its structural rigidity while also appearing flat and smooth.

Walk Assist

Walk your bike alongside you, up a hill, or anywhere you need to with Walk Assist, which allows the bike to maintain a constant ~2-3mph based on your walking speed.

Controller Compartment

Big Sur's controller is mounted right near the pedals, allowing for easy access during repairs and maintenance. Plus, this mounting style allows the controller to utilize the entire frame as a heat sink, greatly improving safety and performance under load.

Video Gallery

Video Gallery

Assembly Guide

Our dealers follow this official assembly guide to make sure your bike is ready to ride.

Big Sur vs. Aventon

How does our bike stack up against the competition? Check out our head-to-head comparison.

Ride Review

Big Sur looks great in person, and even better in motion. See where it can take you!

Customer Reviews

Based on 56 reviews
Fun ride but Lacking

While I enjoy riding the bike, there are several things that could make it better.
1. I have had the chain get stuck twice now between the gears and hub wheel when trying to adjust down to 1st gear. I have taken it in once to the dealer to have it adjusted but it occurred again. The 2nd time it was extremely difficult to get released in that I am considering carrying some type of tool to to grab the chain and provide me a better pulling point. I now try to prevent this by staying far away from 1st gear.
2. An even bigger issue is the lack of adjustment on the torque sensor. I want to be able to adjust the amount of effort I apply for more exercise. To try to extend the range to the maximum, I use level 1 assist and monitor the wattage being used and try to keep it around 100 to 150 and/or the cadence to around 30 or so and/or speed between 10 and 12 mph while peddling. I find the bike too easy to pedal and don’t feel like I get to put in any effort on my part to contribute to extending the range. Today I rode for around 3 hours mostly at this easy rate along a bike route in Houston which is mostly flat although it was a ride along the Buffalo Bayou and White Oak Bayou so did have some up and down movements on the trail. I would coast on the downward trails and coast when I found myself exceeding the above parameters until the return portion when I increased to level 2 and quicker cadence and speed up to around 17mph and ended up using around 70% of the battery.
3. The bike manual is not complete and I believe has at least one error when discussing the screen view on how to adjust between ODO, trip distance, cadence, etc. The manual on page 28 says to hit an i (info) button to change between views but I think it should actually say hit the power button on the display. The display description on page 26 says item 5 is Time Indication. Is this meant to be the elapsed time of the trip, total time on the bike or just a clock. It says there is Bluetooth indicator on the display. What is the Bluetooth indicator for? Do not see any description of it’s use other than it is there. Some really cool app that will capture all kind of great ride statistics and map via a gps phone or other gps device? Don’t bet on it as I have not seen any Android Apps although I have to admit I did not check my iPad for apple apps. Should we expect an app that will work with the bike? The manual does not include a section for how to reset trip info on display.
4. Found the info on how to reset the trip info on the display panel in the frequent questions section. Don’t understand why this was not include in or with the manual. Do not understand why this document is not located alongside the manuals for the bikes on the website. Shouldn’t be so difficult to find.

Item 2 is the biggest issue to me. Need to be able to adjust the level of assist provided for the different assist levels to allow user to put in more effort while riding. Currently it is all or none with the assist levels just allowing a higher rate of speed.

FYI… I use a QuikRStuff bike rack and ramp to move this heavy bike around. Expensive but seems to work quite well for me although there are a couple of pinch points and idiosyncrasies.

Hi, thank you for your thoughtful feedback on our bike. We appreciate you taking the time to share your experiences and suggestions. Regarding the chain issues, our factory is already working on a solution, and we plan to offer an upgrade in the future to prevent this problem. For the torque sensor adjustment, our goal was to enhance the riding experience by providing optimal assistance. If you want to put in more effort, we currently recommend manually turning the assistance function on and off. However, we understand the need for more flexibility and have noted your suggestion for future improvements. We also appreciate your feedback on the manual and will ensure that the necessary information is included in the updated e-bike manual. Your insights are invaluable to us, and we are committed to continuously improving our products. Thank you again for your valuable input.

Steve Lagerstrom
Awesome bikes - better than Aventon!

My wife and I picked up two of the Big Sur ebikes last week and have been absolutely loving them! We have ridden for at least a couple hours every night after work and the smiles never leave our faces.

We were comparing with the Aventon Aventure 2 and feel like the Big Sur’s are more comfortable, equally powerful, look better (loves the tan sidewall tires) and the standard grips and saddle are much better from AIMA. The larger rear rack allowed us to put two large bags on the back that carry all the gear we need. They’re great bikes on or off road and turn heads everywhere we have been riding.

Only one small issue so far - the front fender has two support bars that attach to the wheel and one of the bolts on my bike worked loose and fell off so now the support bar and fender are flopping around. Have not been able to find any AIMA parts online so hopefully somebody from the company reads this and lets me know how we can get a new bolt!

Thank you for your fantastic feedback! We're happy to hear you and your wife are loving your Big Sur ebikes. For the front fender issue, please reach out to our customer service at We’ll address your problem right away ☺️. Happy riding!

50 miles chain linkage catastrophe

Be careful changing gears up or down hills this thing almost left me stranded in a canyon after the gear linkage system rolled up like a cartoon.

Hi Karl, We are so sorry for your experience. If you accidentally touch the rear derailleur during your ride, it can lead to deformation of the rear derailleur lugs, making it more susceptible to breaking. However, our new e-bikes have been retrofitted with a rear derailleur protection bracket. If you need any kind of after-sales service, please contact your dealer. As a manufacturer, we provide the best after-sales support to our dealers.

Steven Hammersmith
test drive

First time test drove Big Sur. Very nice. Almost identical to Mokwheel except it has a weird ECO feature, have to pass 15mph to get into power mode. I did not see that on Big Sur. Will need to add a neck to bring the handle closer. I also need to know how it handle steep hills and what is the NM?

Hey Steven, thank you for sharing your experience! It's great to hear your positive impression of the Big Sur. Regarding adjusting the handle position, using an adjustable stem could be a helpful solution to bring the handle closer to you. When tackling steep hills, it's important to use low gears and high torque. For further assistance with this and other inquiries, reaching out to your dealer would be beneficial as they can provide professional advice and support. Also, the torque value of the Big Sur is 85NM.

Stephanie Spencer
Main mode of transportation

This bike has given our special needs son his independence back!! (We had the throttle disabled for safety reasons). He is a 6’4” large framed gentle giant who works 5 days a week and lives independently but does not drive. He loves the bike, feels it supports him well and we are so happy with the safety of this bike.

Our only issue is getting enough storage for him to get his groceries home. We have a large back rack and saddle bags but are in need of a front rack to fit the Big Sur 26. Could you please recommend a large front rack for this bike. Thanks!!

Hey Stephanie,Thank you for sharing how the Big Sur has empowered your son's independence—we're happy to hear it! In regards to your storage needs, we've got you covered. Our large front rack designed for the Big Sur 26 will be available in early June. Simply reach out to your dealer then for more details. Thank you for your support!

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