Big Sur Sport 20" Ebike


Out of Stock

Everything you love about the original Big Sur is back! Now sporting 20" x 4" fat tires, Big Sur Sport is smaller and lighter, but it's just as fun and performant as Big Sur 26", if not more so! This bike retains the original's class 2/3 rating (20mph and 28mph top speed using the throttle and PAS respectively), as well as its safety features, including big 203mm brake rotors, LG 21700 battery cells, and a full UL2849 certification. Equipped standard with the AIMA Comfort XL seat and an MIK rear rack, Big Sur Sport delivers the same level of power, comfort, and smoothness of its bigger brother.
Technical Specifications


Big Sur Sport


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


74 lbs. (Battery included)


9/16' Alloy Platform


Suspension Fork with 80mm Travel, Adjustable Preload & Lockout


400 lbs.


Included, Aluminum Alloy Kickstand 


160mm w/ 52T


Shimano 7 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 


20" 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.

Geometry and Fit


Hub Motor and Battery

There's few places you can't go with Big Sur Sport, thanks to its powerful 750W (nominal) rear hub motor by Bafang paired with a 48V 15Ah high-capacity battery.

Torque Sensor

Rather than relying on an outdated cadence sensor to detect your movement, our torque sensor is able to instantly feel how hard you're pedaling at any given time and instruct the motor to match your performance, improving safety and efficiency.

Full Color Backlit LCD Display

Everything you need is right in front of you at all times, including your current speed, battery remaining, distance traveled, and much more.

20” x 4” Fat Tires

20” x 4’’ tires enable you to traverse any terrain with ease while retaining the nimble feeling of a 20" tire. It's the best of both worlds!

Suspension Fork

Offering 80mm of travel and adjustable preload & lockout functionality, our suspension fork provides a smooth and comfortable ride feel throughout a wide variety of riding conditions.

Fender & Rear Rack

Fenders come pre-installed to ensure you'll be able to tackle all sorts of weather conditions. Plus, an included MIK HD rear rack means there's no limit to what you can take with you.

Flat Position Welding

We've applied one of the most advanced aluminum welding processes to our frame, an exclusive "flat position welding" technique. This allows the frame to maintain its strength and rigidity while also appearing smooth and flat.

Walk Assist

Gone are the days of pushing your bike around by hand. Our walk assist function allows the bike to maintain ~2-3mph (walking speed) as you push it alongside you, up a hill, or anywhere else.

Controller Compartment

Mid-drive? Not quite! Our mid-mounted controller cavity allows for streamlined assembly and repair, while also bolstering the controller's heat dissipation capabilities, improving the bike's performance and safety.

Video Gallery


Introducing the All New AIMA Big Sur Sport: 20" Tires, Same BIG Power

Think Big Sur power, but bite-sized! Discover the eBike designed for everyone, with all the muscle of the original.

The Best just got...Smaller? | Big Sur Sport | Affordable, Approachable...

This approachable step-through Ebike has all of the top-notch features from the Big Sur, but now comes in a more approachable 20" tire platform.

AIMA Debuts at CES, Launching a New Global Strategy

In its first appearance at CES, AIMA aligns with the show's focus on sustainable development and mobility technology.

Customer Reviews

Based on 6 reviews
Vincent Dao
Glad that we paid more!

We found these bikes by accident while looking at Aventon Sinch.2. Those are foldable and cheaper which were the big pluses for us. But after riding these Big Sur sport, we both liked these more but the total cost for 2 of these bikes were $600 more. Additionally, we have to get a more robust bike rack. However, it was all worth it. The bikes are beautiful, solid, smooth and powerful. We took them to the beaches, roads and trails. They climbed up the hills with no problem, even when there r loose dirt and rocks. We have had them for like 40 days and have put 200 miles on it. The MK rack is so convenient. We just need to pop the accessories on when we are ready to bike and pop them off when we are about to load them onto the bike rack. The only thing we didn’t like is the headlight which is pretty weak and almost useless haha sorry Aima! No one is perfect! . Hopefully Aima will come out with a better headlight that we can swap out. Otherwise, buy these, you won’t regret it.

Best bike on the market.

I absolutely love this bike it is unmatched in comparison to all dealer E-bikes.

Hey, thank you for the amazing review. We appreciate you recognizing our ebike, and we will continue to create better ebikes for our customers!

William Edelen
No regrets

I have the big surf sport 20 " in white. It has exceeded my expectations. The bike is loaded with brand-name parts and is UL-approved. Living in a relatively flat area I never shift out of high gear. I use a quick bump of the throttle to get rolling. The white color keeps my battery from heating up in the sun. The build quality of the bike is excellent the frame has no weld marks like most of the others have. Having a torque sensor instead of a cadence sensor that you find on most other bikes, is a game changer. Most of the bikes this size have a post handlebar. Yuck. The handlebars on this are adjustable and swept. Much more comfortable for riding. I did extensive research before purchasing this bike. For the money this bike is by far the best value. I could have ordered online but chose to order through a bike shop. They charged me $200.00 to assemble and deliver the bike. The price is the same online or at the bike shop so give your local bike shop some support. If you ever need service you'll be glad you did. I have no regrets about buying this bike. I'm 5' 7" and 65-plus years old. The addition of a suspension seat post made this bike perfect. If you buy this bike I'm sure you will have no regrets.

Thank you, William, for your detailed and enthusiastic review! It's great to hear that your Big Sur Sport has exceeded your expectations. Your insights on the build quality, parts, and features are greatly appreciated. Enjoy your rides, and thank you for supporting our local dealer shop!

Extremely proud owner!

First and foremost, I want to thank you for creating such an awesome e-bike. I just purchased a Big Sur Sport at High Voltage Ebikes in Largo, FL. I have to say that at first I was on the fence whether I bought a Mok Wheel or the Big Sur. The guys at High Voltage E-bikes allowed me to test ride the Mok wheel first while they were quickly assembling the Big Sur Sport so I could see the difference between them both. When I got in the Big Sur I loved the comfort and ease of riding. By the time I got to the corner of the shop I was already convinced that it was the best and the right fit for me. Excellent bike and an amazing comfort. Great solid construction, great looks. My brother in law has the Big Sur 26. He highly recommended it for me. But I was inclining towards the Mok Wheel, that was until I got in it. Once again thank you for such a great e-bike. I love it!! The best choice out there for e-bikes.

Hi Frankie, that's fantastic to hear! We're thrilled that you're enjoying your Big Sur Sport e-bike. It sounds like you had a great experience at High Voltage Ebikes, and we're glad they could help you make the right choice. We're committed to creating e-bikes that provide comfort, ease of riding, and solid construction, so it's wonderful to hear that you're loving the experience. Thank you for choosing our Big Sur Sport, and we hope you continue to enjoy many rides ahead!

Roy Koberna

Been trying to find out when the local dealers in Vero Beach ,Fl. will be recieving the SPORT 20" E-Bike & what will be the introductory price when they become availsble?

Hi Roy, it looks like we have a few dealers in your area. Your best bet would be to reach out to each dealer individually and ask if they can place an order for you if they don't already have any in stock, we have several warehouses around the US including in Florida to ensure fast shipping times. Big Sur Sport's price is currently set at $1799, and it it's up to our dealers to provide discounts when/where they feel appropriate. Here are a few dealers you may want to contact, hopefully this helps!

- Alan's Bicycle Center
2020 Commerce Ave, Vero Beach, FL, 32960
(772) 562-2453

- E Power Bike Shop
137 Sebastian Blvd, Ste D, Sebastian, FL, 32958
(321) 419-3375

- Electric Bike Shop
6510 NW Selvitz Rd, Port St. Lucie, FL, 34983
(772) 800-3857

Get in touch

Have questions about your order, or a general inquiry?