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Tern Vektron Review – Nimble, Folding e-Bike Run-About

E-bikes are a touchy subject here at Bike World News. Cycling at its purist, is about human powered propulsion. We might not agree with the e-bike categories that are popping up in races around the world, we can see a valid use in the utility market. Whether it is a commuter or cargo bike, each will help you get to your destination quicker and easier. When Tern approached us about testing one of their folding bikes, I saw it as an opportunity to experience an e-bike for my daily commute. The day the Vektron S10 arrived, I took my first step into the e-bike world.

The Tern Vektron

The Tern Vektron is a 20” wheel folding e-bike, powered by a Bosch Active system.  At $3,400, it's not cheap to say the least, but depending on your situation, it could just about replace a vehicle.  It's well-appointed, with a Shimano Deore Shadow rear derailleur, Deore hydraulic disc brakes, FSA crank arms, Schwlabe Big Apple , Ergon grips, rear rack, fenders and front and rear lights, not to mention the name brand Bosch Active system, so you are getting your money's worth.

The Vektron folds down small enough to fit in your car or under a desk.

Before I could take it out for a spin, I needed to get it set up and sized for me. The bike came folded in the shipping box, so it was just a matter of unfolding the two joints (middle of the frame and just above the steerer tube) back together, locking them in place with their levers, and extend the telescoping seat post. The pedals were in the holder under the saddle, and inserted into the crank with a click. The are height adjustable by flipping to leavers and moving pivoting bars that you would consider the stem up and down, but you can't really adjust the reach. Tern says it should fit anyone between 4'9” and 6'5”, so there is a pretty wide range of adjustment.

Once on the road, I started with no boost at all, just to get a feel for how the bike rides on its own. It was heavy, but with a wheelbase comparable to a full size bike, it didn't feel all that different. With the Bosch Active system, the boost only works when you are pedaling, so you can't be one of those guys flying by other cyclists without pedaling (essentially an e-ped) or even worse, an Amish kid on a scooter with an electric front wheel kneeling down in an aero tuck behind the basket on the front of the bars, going by you at 25 mph. But I digress. The 36V/250W system has a max speed of 20 mph, so any faster than that you want to go, you have to generate the power yourself, which is definitely doable, even on flats.

The display shows your speed, boost mode, and battery level…

To try out the boost, I started with the assist on Eco, the lowest of the four settings on the bike. The boost on eco mode is minimal, which is why Tern says it can get about 62 miles on a charge. Getting the 48lb bike moving wasn't hard, but it was about as spritely as getting your downhill rig moving. I started pedaling up a small hill, so I moved to Tour, which ups the boost a little bit more. The assist was noticeable, but the bike still chugged up the hill. Once at the top, I went back down so that I could try the climb in Sport and modes.

In Sport mode, the bike has more pep. Granted, it decreases your mileage with the additional boost, but it helps liven the bike up. The bike carries speed better, and felt like I was riding with a little bit of a tail wind. Instead of changing the boost midway up the hill, I decided to give Turbo its own run. As I pushed down on the pedal at the bottom of the hill for the Turbo run, the Vektron felt like it jumped off the line. It quickly got up to speed, and carried me up the hill at road bike speeds. That's when I knew my commute was about to get a little more fun.

…or you can swap in the range remaining on the charge.

As part of the review, I knew I wanted to put it through some paces of commuting some distances. My commute to the office was about 18 miles one way, and I've ridden it on my road and cross bikes (and other review bikes) many times to get a work out in before and after work. I was hoping the Vektron would make it a little easier for the days I wasn't looking for a work out, but wanted to be out of the car.

The front light is rather bright, more on the dedicated headlight side than the be seen side.

First, let's go over some of the specs a little deeper. We've already talked about the Shimano shifting and braking, which all performed flawlessly. The Valo lighting system was enough to light up the road to help you avoid potholes and be seen. There are brighter lights out there, but the 150 lumens front light and rear “be seen” light neatly tie into the electrical system of the bike so there is only one battery to worry about charging. The rear rack worked well with the Two Wheel Gear Pannier Pack I used for commuting (review also coming soon), and is rated for 55lbs. The bell is a nice touch for urban commuters, and same with the fenders, although I never really had a chance to test them out in the wet.

The Bosch Active system. Note the quick release on the pedal which allows you to remove the pedal and stick it under the saddle when folded.

The Bosch Active system consists of the motor, the battery, and a headunit where you get speed and batter level information and control the levels of boost. There is also a charging pack for the battery that you can either leave at home, or if your commute is long enough, stash it in your bag to charge at your destination too. It's about the size of a laptop charger, so very easy to take along. The battery has a built in key lock to discourage theft, but also so you can easily remove it and take it with you for charging. A full charge took about 3 hours, which I only needed to do a few times a week, even with generous amounts of riding.

So back to the ride. My route to the office consists of rolling terrain with a few climbs, a nice s-turn section, quiet country roads, and a bit of suburbia. After lugging the bike out of the house, which wasn't horrible, thanks to a support beam just ahead of the seat tube that makes a nice handle, I was on my way. Depending on the boost level, you could hear the motor working as boost was applied. It gave the bike a nice higher pitched hum, and let those near you know you were on an e-bike.

Schwalbe Big Apple tires handled well during testing at high speeds.

The ride was smooth and the bike felt responsive both at speed, and during slower sections. Then came the s-turns. Going into them, there is a bit of a downhill stretch that, with a little bit of vigorous pedaling, I was able to get up to about 35mph. The Vektron carved through the corners like a road bike railing a banked corner. Through the climbs, I found downshifting into an easier gear to keep my cadence up, helped keep the boost and speed up.

Along the country roads, it was a peaceful ride, and felt nice not to be pushing myself to keep my speed up to get to the office on time. Yes, I was still pedaling, and putting out a decent effort, but the Bosch Active system helped keep the Vektron moving.

Once at the office, the bike definitely got its share of looks from curious non-cyclists. A few people even asked to jump on and try it out once I told them more about it. But since it was time for my day to begin, I folded it down, quickly and easily, and rolled it to my desk where I was able to hide it neatly next to my filing cabinet. The Magnetix 2.0 system, which uses magnets to keep the bike folded together when you move it, helped, but I found the Vektron wanted to unfold at times during movement.

The battery can be released using the keys. You can charge it separately, or at a port just below the battery with it attached.

It was a sad day when I dropped the Vektron off at the local dealer in Philadelphia at the end of the review.   I will be the first to admit, the Vektron is a fun “little” bike. If I lived/worked in a more urban setting with better mass transportation, I would definitely see value in something like the Vektron, or any of Tern's models, that you can ride, fold, and take with you. If e-assist isn't your thing, models like the Verge D8 would be pretty comparable to the Vektron. The range, build quality, and ride went a long way to sell me on a bike with little and e-assist. Other than the magnetic system holding the bike together maybe being a little bit stronger, there wasn't much I could fault the bike on. It's well thought out, and comes with just about everything you'd need, besides bags, for a solid commuting bike.

http://www.ternbicycles.com

A set of lights on the side of the battery shows the battery level.
The kickstand comes in handy for a hefty bike like the Vektron.
A Shimano Deore drivetrain shifted impeccably.
The rear be seen light is integrated into the rear rack. The rack held panniers firmly in place during testing.
The double telescopic seat post allows the bike to fit riders from 4'9″ to 6'11”, and quickly drop down when folded.
Shimano Deore shifters and brake levers round out the quality build. The bell is a nice touch for commuting. The levers that the light sits between act as an angle adjustable stem.
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