Tern Vektron P7i Review: The Electric Folding Bike Designed for Modern Mobility

The Tern Vektron P7i is one of the most sophisticated, stable, and high-quality electric folding bikes on the market. By combining a powerful Bosch mid-drive motor with a patented folding mechanism, this folding e-bike offers the riding experience of a full-fledged city bike in a compact, easily transportable package. This became immediately apparent from the very first few pedal strokes during our field test.

Tern and the Vektron Series: A Benchmark in Urban Mobility

Based in Taiwan, Tern Bicycles enjoys a strong global reputation in the field of sustainable urban mobility. While many manufacturers view folding bikes as a secondary product, at Tern they are at the very heart of the brand’s DNA. The goal: to design compact bikes capable of carrying heavy loads, built to last, and designed to make cars unnecessary for everyday use.

Within the Tern lineup, the Vektron family holds a special place. While the GSD and HSD models are true Tern electric cargo bikes with rigid frames, the Vektron was designed for maximum intermodal use: it’s the brand’s most compact model. It’s aimed at commuters who want the power and range of a premium Bosch system, while still being able to fold their bike in 10 seconds to take it on a train, in the trunk of a car, or under a desk. The P7i version was specifically designed as a reliable, low-maintenance city bike.

Technical specifications tested in the field

Motor: Bosch Active Line Plus (50 Nm)

The Vektron P7i is equipped with a Bosch Active Line Plus mid-drive motor, which delivers 250 watts of power and a maximum torque of 50 Nm. This system relies on advanced force, rotation, and speed sensors capable of calculating the level of assistance up to 1,000 times per second.

From the very first few meters, you notice just how smoothly and quietly the engine runs. When pulling away from a crowded red light, it responds immediately and smoothly to pressure on the pedals. The 50 Nm of torque is more than enough to effortlessly tackle a steep hill or a strong headwind. Even above 25 km/h, when the motor cuts off its assistance, the Vektron continues to ride surprisingly lightly, thanks to the low internal resistance of the Bosch motor.

Battery and Battery Life: Bosch PowerPack 400 Wh

Power is supplied by a 400 Wh Bosch PowerPack battery. Unlike previous generations, it is now mounted horizontally on the rear fork.

This design significantly lowers the bike’s center of gravity, which directly translates to stable and predictable handling, even on tight turns in the city. In terms of range, our combined test (alternating between Eco, Tour, and Turbo modes) covered a realistic range of about 60 to 70 kilometers—more than enough for everyday use without the stress of recharging.

Drivetrain: Shimano Nexus 7-speed hub

The drivetrain features a Shimano Nexus 7-speed internal-gear hub, operated by a convenient twist shifter on the handlebars.

A gear hub is the ideal choice for a folding city bike: since it’s fully enclosed, the system is protected from road grime and requires virtually no maintenance. The main advantage noted during testing: the ability to shift gears while completely stopped. If you have to brake suddenly for a pedestrian, simply shift the lever back to first gear to get going again easily. The seven-speed range is perfectly suited to Belgium’s flat to slightly rolling terrain.

Frame Stiffness and Geometry

The high-end aluminum frame is certified to meet the strict EFBE EN15194 safety standards for electric bikes. Thanks to the patented telescoping seatpost (double-tube design) and the adjustable Andros stem, the bike can be adjusted in seconds to accommodate riders between 1m47 and 1m95 tall.

In practice, many folding bikes suffer from a frame that lacks rigidity, a problem exacerbated by the small wheel size. The Vektron completely shatters this stereotype: the frame is extremely rigid. During testing, stability at 25 km/h was such that it was possible to ride hands-free—a feat unthinkable on most folding bikes with 20-inch wheels. The riding position can be quickly adjusted using the Andros stem, from a forward-leaning sport mode to an upright comfort mode.

Folding Mechanism and Intermodality

Tern uses the OCP Joint folding mechanism, combined with powerful Magnetix 3.0 magnets, to keep the bike folded. Once folded, it measures just 41 x 86 x 68 cm.

With a little practice, it takes exactly 10 seconds to fold the bike completely. While the total weight of 22.5 kg (including the battery) makes carrying it up long flights of stairs impractical, Tern has come up with a clever solution: once folded, the bike can be pushed by the seat like a wheeled suitcase. The rear rack is also designed to allow the folded bike to stand upright and remain stable, even on a crowded train. For a broader comparison of available models, check out our selection of the best folding e-bikes.

Brakes, tires Accessories

Safety is ensured by Shimano hydraulic disc brakes and wide tires Big Apple tires (20" x 2.15) featuring Kevlar puncture protection. The bike also features an integrated Atlas V rear rack (27 kg capacity) and a powerful Tern Valo 2 headlight (150 lumens).

Thanks to their large volume, tires Big Apple tires act as a natural suspension system: they effectively smooth out tram tracks and city cobblestones. The hydraulic disc brakes performed excellently in testing: with minimal pressure, even in heavy rain, stopping is immediate and perfectly controlled. The rack is also directly compatible with systems such as the Thule Yepp Maxi child seat, with no adapter required.

Conclusion

The Tern Vektron P7i proves that a compact folding bike doesn't have to compromise on ride quality. Thanks to the robust combination of the Bosch Active Line Plus mid-drive motor, the low-maintenance Shimano Nexus hub, and an extremely stiff frame, this bike rides like a premium e-bike in its own right. While its weight of 22.5 kg is still on the heavy side for carrying by hand, the “suitcase-style” folding system more than makes up for this drawback in everyday use. For anyone looking for the ideal companion for multimodal trips, without sacrificing comfort or safety, the Tern Vektron P7i stands out as the benchmark in its category. Be sure to check out our selection of reconditioned used e-bikes to find the model that’s right for you.

FAQ

What is the range of the Tern Vektron P7i?

With its 400 Wh Bosch PowerPack battery, the realistic range is between 60 and 70 kilometers in mixed-use conditions (Eco, Tour, and Turbo modes). That's more than enough for a daily commute.

Is the Tern Vektron P7i suitable for use on trains and in cars?

The bike folds up in about 10 seconds to a compact size of 41 x 86 x 68 cm. Once folded, it can be pushed like a wheeled suitcase and remains stable when standing upright.

What makes the Tern Vektron P7i low-maintenance?

The combination of the Shimano Nexus 7-speed hub and the enclosed drivetrain minimizes wear and prevents dirt from getting inside. This makes the bike ideal for everyday use with minimal maintenance.

How much does the Tern Vektron P7i weigh?

The bike weighs 22.5 kg, including the battery. While this weight is still heavy for carrying by hand over long distances, the folding mechanism allows you to push it along the ground like a suitcase, which more than makes up for this drawback.

What body types is the Tern Vektron P7i suitable for?

Thanks to the dropper seatpost and the adjustable Andros stem, the bike accommodates riders between 1m47 and 1m95 in height, all with the same level of comfort. For families, the Tern GSD S10 LR model offers a cargo bike option for transporting children.

Written by: Dieter Devriendt | Published on: July 6, 2026 | 6-minute read

About the Author: Dieter Devriendt

A passionate journalist, Dieter writes about cycling with expertise and enthusiasm. Under the motto “we write—we ride,” he gladly shares his experience to help cyclists get the most out of their lives both on and off the bike.