Much like any machine with moving parts, occasionally, you'll encounter problems with your mid drive eBike. One of the most common, and easily fixable is "Error 21" or the Speed Sensor Error.

This particular video is related to our mid-drive (motor inside frame) line up of bikes however error 21 exists for all our bikes. Error 21 is related to the hall or speed sensor which essentially is responsible for your speedometer on your LCD display.

See all possible causes below:

Mid-drive
- Sensor
- Magnet
- Rear motor harness
- Controller

Hub drive
- Internal motor issue
- Controller

In most cases, error 21 for hub drive e-bikes would merit a replacement motor. Reconnecting the motor cable would be the first thing to do before replacing the motor. Regarding mid-drive ebikes, it's all about the process of elimination.

Error 21 can be troubling for eBike riders as it results in being unable to utilize your bike's pedal assist. 

If you have more questions about your Electric Bike whether it be technical difficulties, capabilities of the bike, etc. please free to contact us! Anytime you contact us, a ticket is created and stays open until someone from the team completely resolves it.

 

Submit A Support Request Ticket - CLICK HERE

 

Self Service

The great thing about this system is that if you have a quick question about a common issue, you won't have to sit around waiting for our response.

For Self Service - CLICK HERE

 

The system will suggest articles which contain more info, videos etc. of the most common questions that may come up on your FLX journey.

Other Questions?

Customers are always welcome to contact us directly here on our direct phone line at 844.548.3359. We take calls as they come in and do our best to return any missed calls within 24 hours.

 

Frequently Asked Questions

Have a question? We've got answers.

What's the best commuter ebike?

For daily commuting, the Babymaker II Pro is our most popular pick. It weighs just 35 lbs — light enough to carry up stairs or onto transit — and its Gates Carbon Belt Drive means virtually zero maintenance. A single charge gets you 20–70+ miles depending on assist level.

If you want cargo capacity and a more upright position, the Moonrider is a great alternative with dual racks and a Bafang mid-drive motor that handles hills with ease.

What's the best lightweight ebike?

The Babymaker II is our lightest model at just 33 lbs — significantly lighter than most ebikes on the market. Its minimalist frame and compact battery keep the weight down without sacrificing range or performance. Perfect if you need to carry it up stairs or store it under a desk.

Do I need a license to ride a Superhuman ebike?

In most US states, no license, registration, or insurance is required to ride an ebike — as long as it meets federal ebike classification standards. Most Superhuman models meet these requirements. Rules vary by state and municipality, so we recommend checking your local laws, especially for Class 3 bikes on trails or shared paths.

What's a fat tire ebike?

Fat tire ebikes feature oversized tires — typically 4 inches wide or more. Those wide tires give you more traction on loose surfaces like sand, gravel, and snow, better shock absorption, and increased stability at low speeds or in technical terrain. Great for riders who want to go off the beaten path or ride year-round regardless of conditions.

If you're looking for the best fat tire electric bike for all-terrain riding, the Superhuman Bikes Bomber is our top pick. The Bomber is a 750W scrambler-style fat tire ebike built to go anywhere — sand, trails, dirt roads, or city streets. It runs on a 48V 17Ah battery with 40+ miles of range, 20-inch fat tires for maximum grip, hydraulic brakes, dual suspension, a comfortable bench seat, and optional foot pegs for a moto-inspired feel. Available in multiple colors and two configurations, it's one of the most capable and versatile fat tire ebikes on the market.

What's the best ebike for beginners?

We recommend the Moonrider or the Photon for riders new to ebikes.

The Moonrider has a step-through frame (easy to mount and dismount), an intuitive mid-drive motor, and comes with front and rear racks so you can start using it for real errands right away. Its Shimano 10-speed lets you gradually learn how to blend pedal assist with gear selection.

The Photon is a great option if you want something lighter with a throttle option, so you can start by letting the bike do the work and increase your own pedaling input as you get comfortable. It ships 95% pre-assembled — front wheel, pedals, and handlebars and you're ready to ride. (And they glow in the dark!)

How long does shipping take?

All in-stock Superhuman bikes ship within 3–7 business days of order confirmation. You'll receive a tracking number via email once your order leaves our warehouse. For the most current availability on specific models, check the product page or contact our support team.

What's the longest range ebike in your lineup?

The Weapon leads the lineup with 70+ miles of range on its 840Wh battery — the highest-capacity battery we offer. The F5 Trail also carries an 840Wh battery and delivers 50+ miles per charge under typical conditions.

Real-world range depends on rider weight, terrain, wind, temperature, and how much you pedal vs. rely on the motor. Using lower assist levels and pedaling more actively will always extend your range.