Big Sur Ebike

$1,999.00

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

MODEL

Big Sur

MOTOR

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

THROTTLE

Throttle on Demand

DISPLAY

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

SPEED

Up to 28 MPH Pedal Assist, 20 MPH Throttle Only

BATTERY

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

REAR RACK

MIK HD

SENSORS

Torque Sensor

PEDAL ASSIST

5 Levels

CHARGER

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

RANGE

30 to 60 Miles

FRAME

6061 Single-Butted Aluminum Alloy Frame with Internal Battery

WEIGHT

82 lbs. ( Battery included)

PEDALS

9/16' Alloy Platform

FORK

Suspension Fork with 80mm travel, with lockout

WEIGHT LIMIT

400 lbs.

KICKSTAND

Included, Aluminum Alloy Kickstand 

CRANKSET

170mm w/ 52T

SHIFT

Shimano 8 Speed

GEAR RATIO RANGE

11-34T

BRAKES

Tektro Hydraulic Disc Brakes

ROTOR

203 mm

CHAIN

130 Link, 8 Speed

RIM

Double Wall Aluminum Alloy

SPOKES

Black Stainless 12G Front / 12G Rear

TUBES

Butyl Rubber

HUBS

Front Aluminum Alloy Disc Hub 

TIRES

26" x 4" Puncture Resistant

SADDLE

AIMA Comfort, 280mm*270mm Saddle

SEATPOST

Aluminum Alloy, 30.4mm 2-Bolt Clamp

STEM

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

SEAT CLAMP

34.9 mm Quick Release

HANDLEBARS

Aluminum Alloy Double Wall, 31.8mm, 680mm

HEADSET

Sealed Bearing Headset

GRIPS

Ergonomic Comfort

*Ebike Range: Explained

An ebike's battery life is influenced by several factors that can affect its maximum range. While our ebikes can achieve up to 60 miles of range under ideal riding conditions, range can vary from 20 - 60 miles based on many contributing factors.

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 pedal 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 forward. Slower speeds will extend battery life.

  • Tire Pressure: Keeping your tires inflated to the recommended pressure can help increase your range. Maintaining a proper tire pressure not only increases your range, but also helps prevent pinch flats! For most riding situations, checking your tire pressure at least once a week will keep your ride safe and energy-efficient.

  • Load Weight: Carrying a heavier load can decrease your range. This includes the total load of both the weight of the rider and any cargo you may be carrying. More weight takes 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 and flat terrain will give you a longer range. Hills and rough terrain can greatly impact your maximum range, especially on higher assist levels.

  • Wind: That's right! The wind can affect your battery range too! Riding into a headwind will decrease your range, but if you're able to catch a tailwind, you'll actually see that you'll gain more range! Be mindful of which way the wind is blowing when you are riding. If you've been riding in a tailwind, turning around will take more energy from the battery to get you home. 

  • Ambient Temperature: Riding in cold weather will impact the battery's ability to function optimally. A good rule of thumb is, if you're comfortable, then the battery is comfortable too. This also goes for storing the battery too!

Exclusively available for purchase at an Authorized AIMA Dealer

Find your Local AIMA Dealer here!

Your Safer electric bike choice

Fully UL2849 Certified

Geometry and Fit

Features

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 60 reviews
87%
(52)
7%
(4)
2%
(1)
5%
(3)
0%
(0)
W
Wendy M
Bad experience- esupport cut out

I rode one of these 10/1/24 as a rental. Three times the e-support cut out in a slow turn going into an incline. The third time I could not get it to kick back in and this heavy bike fell on me. Severely sprained wrist that caught the weight of the bike, plus two fractures in landing foot. I had already ridden 15 miles and am an experienced bike rider.

D
D.R.
Best bike ever

We have the black one and the white one. These bikes are beasts. We love riding and enjoying life. I love how it is well built. It feels very sturdy. They are big bikes. We have the 26”. Love how it rides and handles. Very comfortable. Just wish it would go 28 mph with the throttle.

M
Matt P
Love my Big Sur

I purchased in May and have ridden 900 miles. It would be more but I got creamed by a car that had ran a stop sign. Broke 4 ribs and my clavicle. I just got back on it after 35 days. The thing is built like a tank. Aside from a broken light, some cometic scrapes and scratches it seems to be no worse for the wear. I seems that my dealer is having a hard time getting parts however. Parts for the light have been on order for almost a month.

P
Paula Cardinali
Almost perfect

I’ve had my Big Sur for about a month now. It has taken me about that long to get it setup the way I prefer. I added a nice suspension seat post, handlebar riser, and handlebar extender to bring them closer to me. I love the feel of the bike, but I wish I could adjust the torque sensor so it’s harder to pedal. In order to get my heart rate up, I have to turn off the PA, then turn it back on. I wish there was an adjustment to lessen the ease of the PA. I’d also like to see signals added to the bike. The headlight seems to be a common issue. It doesn’t tighten, and it’s really big and bulky. A smaller, more powerful light would be better.

I tried riding my other bike, which is a cadence-sensored bike. It is hard going back to that smaller frame with Les’s suspensions. However, I burn more calories on that bike. I was hoping the torque sensor would require me to work harder and burn more calories.

C
Customer
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.

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