Tern Vektron Electric Folding Bike Review

Josh Ross
eBicycles score

Tern is a folding bike company.

Actually, Tern likes to say they make bikes that fold, not folding bikes. Either way though the Tern Electric bikes-including the Tern GSD, HSD, and Vektron- might feel a little different at first glance.

Look a little closer though. Spend some time with the Tern electric bike models and there’s a story line.

The Tern GSD, HSD, and the Vektron are like a path leading through the needs of different buyers. It can feel a little confusing but I’ve spent the time it takes to decode the story.

Start with the Tern GSD. It’s the largest of the three models. It has room for two kids and a 440lb gross vehicle rating. The next place to move is the HSD.

The HSD downsizes the available carrying capacity and it’s shorter. The shorter frame means a limit of one child. Neither the HSD or the HSD folds in the way one expects a folding bike to work. The handlebars fold down and out of the way but the frame doesn’t fold. They represent cargo bike options and they offer a choice of sizing.

Tern Vektron Overview

The Tern Vektron keeps moving down the same path and it’s even smaller. The Vektron is the model that most closely matches the other bikes that Tern has earned a reputation for. It folds in half in a way that likely seems familiar to anyone who’s ever paid much attention to a folding bike and it’s not meant as a cargo bike.

While the GSD and the HSD are very similar except with different carrying capacities the Vektron is closer to other Tern models. One thing that does remain constant through all of the Tern electric options is that each model has a variety of options available.

Let’s take a look at everything the Tern Vektron offers and break down the available options.


Tern HSD Frameset and Common Features

In 2016, after 6 years of successfully building bikes, Tern took a new design to Kickstarter. The Tern Vektron launched directly to an audience of potential buyers. Kickstarter can be a good way for small companies to judge buyer interest and expand with low risk. There was an appetite for the Vektron and backers helped overshoot the goal by more than $30,000.

At the end of 2020 the original Vektron got some updates. The upgrades are evolutionary in nature rather than revolutionary.

New drivetrains, a stiffer frame, easier battery access, and small details such as color. As with all of the Tern products the updates came from listening to what the community of owners reported. “We’re constantly listening to our dealers and riders, and we’re committed to making changes based on that feedback,” stated Tern Team Captain Josh Hon.

“Those who live in hillier areas have asked for a Vektron with a more powerful motor to tackle even the steepest hills. The new Vektron retains its super compact size and superior riding characteristics, but adds the improvements that everybody wants.”

Despite the updates, the original sales pitch has held up through the years.

Electric bikes make the transition from cars easier. Combine the functionality of an electric bike with a folding bike and you’ve got the best of both worlds. Start your day with one plan and if things change fold up your bike and it’s easy to bring it on a train or in a car. Never have to worry about locking an electric bike outside because with the Vektron you can bring it inside with you. Whatever model of Vektron you choose that flexibility will be there.


Vektron Size Recommendation

Flexibility isn’t the only thing that all four models share either. As it says on the Tern website, “The Vektron fits riders of different sizes, with different needs, and also different budgets. That means you can get all the high-quality, award-winning features of the Vektron without breaking the bank.” From the least expensive Vektron D8 all the way up to the fully loaded Vektron S10 there’s a lot that doesn’t change.

To start with, the sizing is a one size fit’s most design and it remains the same for all of the Vektron models. To make starting and stopping easy it’s a low-step frame design and there’s easy adjustability. Without any tools needed riders and between 145 and 195 cm (4’10” – 6’5”) fit comfortably. Make use of the Andros, no tools needed, adjustable stem and the quick adjust seat post to get the perfect fit for you. It’s so easy it even works to share with a family member.

Tern Vektron with a child on the rear rack


Rear rack & other features

Once folded the robust rear rack, strong enough to hold a child in a compatible child seat, helps the Vektron balance vertically.

You won’t need to hold the weight of the bike at all times and can instead rest it on the ground. Use the specially designed seat as a way to wheel the bike while folded or carry it while balanced on your shoulder.

These features remain the same throughout the model lineup just like the unique OCL+ frame joint. The OCL+ features a single-shaft design, advanced welding techniques, and robust gussets. It stays stiff and strong during even the fastest commutes and it’s built to exceed ISO 4210 and EN 15194 testing requirements.

Each model utilizes a unique drivetrain and electric motor system. It’s the primary differentiator but even there you’ll find some similarities. There are always hydraulic disc brakes and there is always a 400Wh battery. Front and rear lights are not always the same but they are always there.

With so many similarities let’s talk about what makes each model stand apart.


Tern Vektron S10

Tern S10 folding electric bike

The Vektron S10 is the top-of-the-line in the Tern Vektron lineup. It has the longest range and the best drivetrain but it also costs the most with an MSRP of $3,699. There’s no need to buy more than you need, that’s why the other models exist. If you need the features of the S10 though, here’s what you get.

The biggest thing that stands apart is the electric drivetrain. The Vektron S10 uses a Bosch Performance Line Cruise e-system. Bosch is a company that recognized the importance of electric bikes early and got out in front of the trend.

Other systems have bridged that early gap but most people still consider Bosch among the best available. The Performance line is the top-of-the-line that Bosch offers. Within the Performance Line there’s further options and the Cruise is the lowest model.

Despite being technically the lowest model, this is probably the best of the three options in this use. Each model in the lineup is very specialized. The Performance Line Cruise uses multiple sensors and fast processing to ensure a natural feel. There is up to 300% assist and 65Nm of support available up to a max speed of 20mph.

The other major differentiator is the traditional bike drivetrain. In the case of the Vektron S10 the chosen groupset is the Shimano Deore 10 speed. The rear cassette is an 11-36 although the rear derailleur for Deore supports as large as 42 if you ever needed to change gearing. Braking is hydraulic and for the S10 Tern uses Magura MT4 dual piston calipers.

Although it is a small difference the S10 does also include a more powerful front light than the other models in the Vektron range. With 190 lumens the Tern Valo direct light is bright enough to add illumination in a city environment.

Buy from REI.com

or Buy from TernBicycles.com

Tern Vektron Q9 Review

Tern Vektron Q9 Folding Electric bike

The next model in the Vektron lineup is the Q9. At an MSRP price of $3199 the Q9 represents a $500 saving compared to the S10. Almost all of that savings comes in the different electric motor. Instead of a Bosch Performance line motor the Q9 employs a Bosch Active Line.

Although the two motors are similar in many ways the Active line does represent a step down. The Performance line focus is that of performance and versatility. In contrast, the Active line is all about urban mobility. While max speed is still limited to 20mph the way you get there is different. Max torque and max pedal assistance are both lower at 40Nm and 250%, respectively. Both units are high quality but if you expect to carry a lot of cargo, or a child, up a lot of hills then think about the S10. The more powerful Performance line will mean less pedaling and easier climbing.

Other changes to look for in the Q9 include a 9 speed Shimano Alivio drivetrain with an 11-32 rear cassette. Alivio is a step down in the Shimano groupset hierarchy but the biggest difference is a change from 10 speed to 9 speeds. It can be difficult to say how much that will affect any particular rider.

It will mean less options to pick the perfect gear for your ability and environment but as this is not a race bike it may not mean a whole lot. More importantly is going to be the reduced climbing ability caused by a smaller easy gear. The included easy gear gets reduced from 36 tooth to 32 tooth and the max capability goes from 42 tooth to 36 tooth.

The difference here is all about hills. If you live somewhere with lots of hills, and especially if you expect to carry lots of cargo, then the S10 will be a better choice.

Buy from TernBicycles.com

Tern Vektron P9 Review

Tern Vektron P9 Electric Folding Bike

The Vektron P9 represents another $500 cheaper model with an MSRP of $2699. Like I said above, the Vektron lineup is very clear. There’s not a lot of discrepancies in terms of what you get and the pricing. Start from the top and move down the lineup and each model is less expensive. The money saved comes from different electric drivetrains and different mechanical drivetrains.

Once you move to the bottom two models of the Vektron lineup you leave the Bosch mid-drive electric motors behind and move to Bafang systems. Bafang is well known for its rear hub motors and it produces a ton of them. They are less well known for their mid-drive systems and in the US and Europe they aren’t a common option. They might not be a common option but they do have some advantages.

The Bafang M400 found on both the P9 and the D8 is a torque monster. With 80Nm on tap it’s more than either of the more expensive Bosch systems. Also on par with the Bosch systems is the 400Wh battery utilizing Panasonic battery cells. While these specs are on par with Bosch, for less money, the reason that you might choose Bosch is in the software.

The easy part of creating an electric bike motor is the hardware. There are a variety of companies that have products with awesome specs on paper. The more experienced companies, with more refined products, work more on the software. The software becomes the magic used to create a more natural, usable, riding experience. Bosch has been working on that rider experience for longer than most and they have the resources to throw at the challenge. Bosch also has a better warranty with 2 years post purchase vs 36 month post manufacture for Bafang.

Along with the change in the electric motor system comes a change in mechanical drivetrain. The Vektron P9 moves from a Shimano mountain bike drivetrain to the road focused Sora groupset. It’s a 1×9 implementation with an 11-32T rear cassette.

One small oddity in the Vektron range is that the P9 uses a unique kickstand. Other models in the Vektron range use a variety of different rear mount kickstands while the P9 gets a center mount double kickstand.


Vektron D8

Tern Vektron D8 electric folding bike

Shaving another $500 off the MSRP from the P9 brings you to the D8 priced at $2199. With a price tag that is $1500 less than the top-of-the-line S10 this model might actually be the best value in the whole Vektron lineup.

The electric drivetrain remains the same between the P9 and the D8. The same power, and the same battery, mean no difference in the electric part of the riding experience. There’s also the same exposed chain and same light. You’ll have to look hard for changes to the D8.

The primary difference is in the mechanical drivetrain. There’s a 1×8 Shimano Claris system with an 11-32 rear cassette. Claris represents the most affordable complete groupset that Shimano makes. With only 8 gears to choose from, it’s the least available gears in the Vektron lineup but the range remains the same. That means not much difference in what the bike can do but you might find yourself using a less than ideal cadence.

The Vektron D8 also loses the hydroformed aluminum front fork found on the rest of the model lineup. In its place is a steel fork but the overall weight of the bike actually decreases slightly.

With so many similarities and so few compromises the Tern Vektron D8 represents a real value in the lineup. The buyer gets almost all of the functionality with a lot of savings.


Assembly and Delivery

Tern offers some bikes for sale directly through their website but it’s not as simple as it might seem. All Tern bikes sell through dealer partners. Even if you are able to purchase directly through the Tern website a Tern dealer is the one who will be handling your order.

Tern believes that a local relationship with a dealer makes for a better experience. Because of this Tern asks that a local dealer handle last-mile delivery. The local dealer will handle assembly, final tuning, and provide a personal touch for teaching maintenance and operation. it is possible to order Tern bikes for shipment though.

Not all bikes who use a dealer network allow that arrangement but Tern does. If you have the bike delivered it will arrive in a box, like other bikes, however given that it’s a folding bike it requires even less assembly.

Because Tern bikes fold the handle bars are fully assembled when shipped. Similarly, wheels are ready to go as well. The only items that need installation are the pedals and any accessories. If you order any of the many accessories Tern sells, they will come in a separate box.


Our Verdict

The Tern Vektron is one of the best choices for electric bikes on the market. Tern bikes are already a great way to get out of your car without having to make sacrifices or arrive everywhere a sweaty mess. The Vektron takes all that utility then gives an option that means easy transport and tons of flexibility. Whatever your day throws your way all you have to do is fold up your bike. Easily take it in a car, on public transit, or into an office or apartment. You don’t have to worry about theft because you can bring it with you.

The Vektron is also a bargain in the electric bike market place.

Solid after purchase support and a quality build at a price point as low as $2199. If you want to drive less and ride more you can do so at a great price of entry and with a bike that won’t take up valuable living space.

Shop Tern Bikes on REI.com

or Shop on TernBicycles.com

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