The Flex’s 21-speed drivetrain provides riders with a gear for almost every situation.
Experts and owners say The Flex accelerates quickly and smoothly.
The Flex can climb long, steep hills using only the throttle.
A tester recorded 27 to 47 miles of range from The Flex.
An expert reports “sporty” handling on gravel, pavement and gentle dirt roads.
A wide gear range allows Flex riders to maintain pedal input and exercise levels.
CST ‘All Terrains’ 1.95” tires suit riding on both paved roads and light dirt trails.
Several owners feel The Flex is offered at a fair price.
The Flex is said to be a comfortable ride with a comfortable saddle.
Assembly was easy for owners of The Flex.
The Flex’s unbranded suspension fork features a lockout, preload adjustment and 100mm of travel.
Owners say The Flex has a sturdy build quality.
Experts and users say The Flex operates quietly.
Owners say The Flex is light enough to ride without assistance.
The Flex’s battery can be removed for off-bike charging or security.
The Flex is fitted with a Spanninga Axendo 40 headlight, operable from the display.
Many owners feel that The Flex is an aesthetically delightful bike.
More than one owner noted great support from The Flex’s manufacturer, GEN3.
The Flex comes packed with an “essentials bundle” containing a multitool, water bottle, bottle cage, lock, pump and phone mount.

7 reasons not to buy

Some owners and experts feel that The Flex could do with better, hydraulic brakes.
Riders say The Flex’s assist surges before suddenly dropping off.
One 6’1” rider felt that The Flex was just big enough for him.
An expert describes The Flex’s display as small, dark and off-center.
One owner reports The Flex’s bottle cage bolts obstruct lowering of its seatpost.
Riders have received their Flexes with a broken light and a bent derailleur.
An owner says The Flex’s bottle cage obstructs removal of the bike’s battery.

Bottom line

GEN3’s The Flex is a Class 2 e-bike offering both pedal assist and a throttle, topping out at 20mph. GEN3 advertises honest, modest and believable specs that are backed up by testers and owners. The Flex’s build places it somewhere between a hybrid and low-key mountain bike. Tires are mixed-tread but not knobby. With a 100mm suspension fork, it does fine on gravel or easy dirt roads. It definitely suits commutes but isn’t built for raucous trails. The Flex’s 10.4Ah battery achieves a range from 27 to 47 miles, depending on the pedal assist level used. Some minor quality-control issues have been reported. With 21 speeds, The Flex has a wider gear range than most competing e-bikes. Experts and owners see the price as fair.

By Owen Jesse

Expert Reviews

85/100 based on 2 rated expert reviews

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SpiderWayne

Level 1 expert

Gen3 The Flex. Get Out and Ride

Level 1 expert

For The Flex, pavement is my preferred surface to ride on… It’ll hold up to 280lb, I believe.
The Good: Sleek look, all terrain tires, commuter friendly, price!
The Bad: Lets’s see, I wish it came in a few more colors.

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Electric Bike Report

Level 3 expert

GEN3 The Flex Review 2022

Level 3 expert

If you are looking for an e-bike that has a wide gear range, is sporty and doesn’t break the bank then GEN3’s The Flex is a worthy option… We wouldn’t mind seeing some slightly stronger brakes on the future models of this bike…

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CleanTechnica

Level 2 expert

The GEN3 Flex E-Bike

Level 2 expert

…fairly standard wheels and tires, a realistic riding range, a sub-$2K price, and a completely reasonable top speed of 20 mph… all of these “tame” aspects of the GEN3 Flex e-bike are actually very positive features… a solid e-bike for both trails and roads, and well worthy of consideration as a daily driver for commuting and grocery-getting…

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