2017 Tern Vektron Review


Technical Specs & Ratings





Class 1




Hydraulic Disc



396 Wh

396 Wh

49.4 lbs / 22.43 kgs


Flux Pro, Sealed Cartridge Bearings, 1-1/8"

Andros™ Tool-Free Adjustable Angle

Flat, 24.5" Length

Ergon GP1 Ergonomic Grips with Lockers

Telescopic Seatpost™, Aluminum Alloy

Porter+™ Dual-Density with Gel, Integrated GripPad™ Handle

VP K218 Alloy Spindle with Plastic and Rubber Platform, Right Pedal Has Quick Release

Hydraulic Disc

Shimano Deore Hydraulic Disc with 160 mm Rotors, Shimano M615 Levers with Adjustable Reach

More Details


5 Year Frame, 2 Year Electronics and Battery

United States, Europe, Worldwide



17.5" Seat Tube, 22.5" Reach, 23.5" Stand Over Height, 41.5" Wheel Base, 63" Length, Folded Dimensions: (33.5" Long, 27" High, 15" Wide)

Matte Black with Blue Accents

Fender Bosses, Rear Rack Bosses, Luggage Socket™ Head Tube Bosses, Bottle Cage Bosses

Shimano Deore Hydraulic Disc with 160 mm Rotors, Shimano M615 Levers with Adjustable Reach

Video Reviews

Written Reviews

The Tern Vektron is a pretty amazing electric bike, folding or otherwise. I’ve been looking at images of it next to and overlapped with models from different companies and you can instantly see that the reach is longer and really the frame itself is longer. This improves stability, gives you more room to pedal without heal strikes on panniers and toe strikes on the front fender. Thanks to their Andros adjustable stem and telescoping seat post, you get full leg extension and a more comfortable or more aggressive body position depending on how you prefer to ride. I met with Steve Boyd for this review and got very detailed in the video. Definitely check out the pro’s and con’s below because there are lots of little extras to consider that might help to justify the higher price tag if you’re on a budget. This folding e-bike is sturdy, comes standard with all of the cargo and safety features you could want and offers one of the best warranties I’ve ever seen (5 years on the Tern parts standard or 10 years if you register). The Bosch drive system fits perfectly and blends in with the matte black frame. Weight is kept low and center and features like shift sensing let you use all ten gears smoothly without expert execution and timing. Stand out features to me are the pannier rails on the rack which have stoppers to keep bags from sliding off when you fold and roll the bike, a unique dual-clip bungee system, compatibility with Yepp and Maxi child seats, integrated LED lights with a capacitor to keep you illuminated for a minute after parking, forward compatibility with the larger Bosch Powerpack 500, quick release wheels, a magnet and rubber band stay-folded system and hydraulic disc brakes with adjustable reach levers. There is so much more on this bike to dig into, the video review is long but I had a blast learning from the GM of the United States and founding partner so do check it out ;)

Driving the bike is a 250 watt nominal mid-drive motor from Bosch. This is their Active Cruise model designed to feel smoother but it’s still very responsive. All current Bosch Centerdrives measure rear wheel speed, pedal cadence and pedal torque 1,000 times per second to deliver predictable power. The faster and harder you pedal, the more power you get… up to ~500 watts and 50 Newton meters peak. It’s a very capable system but I noticed that I didn’t zoom right up to 20 mph as quickly as with some of the full sized electric mountain bikes and city bikes I’ve tested. In order to hit top speed I arrowed up to Turbo mode using the display panel the switched to the higher gears. One thing I really love about the Bosch controller is that it delivers software driven shift sensing response so the chain, sprockets and derailleur aren’t damaged as easily. With higher end mountain bikes, I usually expect people to be thoughtful in how they shift but those motors offer up to 75 Nm of torque and the rider is often climbing and even standing up. For this folding bike, I found that mashing seemed almost non-existant and the drivetrain hardware, from Shimano, is well made and durable. In short, the motor keeps weight low and centered, is protected by two support bars (to keep it clean and scratch-free when the bike is folded) and it blends nicely with the all-black frame. You do hear it when pedaling at higher RPMs and in the more powerful assist levels but the soft electronic whine isn’t bad. I usually ride in the lower two levels of assist and get excellent range, 50+ miles per charge.

Powering the motor and both LED lights is a standard Bosch Powerpack 400. It’s compact, light weight at just 5.4 lbs and fits perfectly behind the seat tube. This is one of my favorite parts about how the drive system was fitted on the Vektron. Rather than force the battery onto the top tube or onto the rear rack which both cause problems (raising the stand over height or taking up space, weight capacity and destabilizing the bike) they extended the frame and pushed the rack back. I love that this battery can be taken off so easily, even without removing the seat post and saddle. It clicks on in a snap and has a solid locking core and metal latch which keep it from rattling while riding. The pack is surrounded on all sides by frame tubing so it will be safe if the bike tips or there’s an accident and it has an integrated loop handle at the top so you’ll be less likely to drop it while transporting off the bike, perhaps to charge it? The pack can be charged on the frame if you’d like and the charger is fast, offering 4 Amps of output vs. just 2 Amps on many other electric bike chargers. It’s compact, lightweight and connects in a way that feels solid like the pins won’t get bent. Note that Bosch now offers a 500 watt hour battery which is compatible with the Vektron and all other current designs. The pack is the same physical size but weighs more and costs more.

Operating the Tern Vektron is a snap, once the battery is charged and mounted correctly just press the power button along the top edge of the Purion display panel / button pad. This display is not removable like the larger Bosch Intuvia which makes me a little sad (especially for a folding bike which could get bumped around more) but it’s thin, easy to read and relatively easy to use considering it packs in almost all of the Intuvia features. You even get a 5 Volt Micro USB charging port on the left edge to use with a phone, music player or other portable electronic device. That amazed me to be honest, and I love that the walk mode worked with the demo bike we had because some of the older Bosch systems had it disabled for the USA. Walk-mode is great for times when you’re pushing the bike up a steep ramp or hanging out with a friend but carting around the bike with added bags and cargo. So once the display is on, you have to be in one of the four levels of assist to then press and hold walk along the lower edge of the control panel. I like that the Purion display lets you operate the lights by holding plus for a few seconds and that the headlight has its own on/off slider switch. The thing is very bright and I was told it’s a custom design from Herrmans. You can swivel it down or straight and it has some visibility along the sides with two small LEDs that stay lit for a while after the bike is shut down. This is a European feature that few e-bikes get in the USA. And that’s the thing about the Vektron, it only comes in one size and one color but it’s so adjustable and well designed that I think it will satisfy a wide range of use cases and they were able to keep the price down a bit through economies of scale. Sure, you probably feel like $3,400 is a lot of money but just a couple years back you couldn’t get any Bosch powered electric bike for under $4k, and that’s without a lot of the cool extras and premium components seen here.

Ultimately, the Vektron satisfies more than just the folding ebike scenario. It truly rides more like a full sized bicycle. The frame is longer, stiffer and more versatile but the weight isn’t unreasonable (at just under 50 lbs). Nice upgrades like locking Ergon GP1 grips, Shimano hydraulic disc brakes and a tight chain cover mean you really don’t need to accessorize the bike and they all look nice and just work well together. I appreciate when the manufacturer finds or designs parts that don’t rattle, stay out of the way and look good. The only area I’d think about upgrading is the seat post, perhaps adding a suspension seat post to improve comfort further. The larger tires help and in many places, if the roads are smooth this isn’t an issue. But if you truly plan to test the 40 to 80 mile range or take this thing traveling, the gel saddle and ergonomic grips might fall short and leave you with a stiff back and neck. Do adjust the bars and the seat post, take your time to remember what heights work best for you (using the markings on the post) then consider a 27.2 mm Thudbuster or Bodyfloat. I recommend going with a more premium post here because if you lift the bike by the nose of the saddle (as it is designed to do) one of the more basic suspension seat posts could break, they just aren’t as strong. Shout out to Tern, Josh and Steve for partnering with me for this review and hanging out at Interbike where I first got some insights to share back here.


  • The frame feels solid but isn’t bulky, some folding ebikes have large joints that can bump your knees or theighs when mounting and pedaling but this one does not
  • I was really impressed by how quiet the Vektron rides, even at higher top speed, the rack system, lights and fenders stay quiet and feel sturdy
  • The front fender is extra long with an oversized build and mud flap, it should protect your feet and shins well and won’t get bent if you accidentally kick it while turning etc.
  • When folded, the bike really stays put thanks to a magnetic clasp AND rubber strap with multiple tightness holes… some folding e-bikes don’t have any systems to keep them from coming unfolded
  • The saddle is very cool, not only does it have a rounded plastic insert at the nose for you to use as a handle when moving the bike but it also has a pedal holster (for the quick-releasing right pedal when you fold the bike), note that carrying the bike by the seat when using a seat post suspension may cause damage to some cheaper suspension designs, consider 27.2 mm Thudbuster or Body Float
  • Beautiful aesthetic, it’s simple and clean with the black wires and cables blending in nicely along with the battery and motor casing
  • A lot of time and attention went into the buckle clasps, they lock securely, can be adjusted and even serviced with new bushings… and they don’t flop around (Tern has a patented flat-fold design)
  • I love the rear rack because it offers plenty of space on top and on the sides, it felt secure and can carry up to 55 lbs, the pannier bars on the sides have little metal protrusions to stop bags from sliding off the back when you fold and wheel the bike or if you’re noticing that your heel is striking your bags while pedaling (you can mount the bag further back to avoid this but know that the bag won’t slide off)
  • The Bosch charger is compact, relatively light weight and super fast putting out 4 Amps vs. most that just offer 2 Amps, you could toss it into a pannier, trunk bag or use the included bungee system to tie it down and bring it along (full charge in 3.5 hours)
  • This bike can be wheeled along with the bars when folded (as demonstrated in the video review above) and has a walk mode so it will help you carry its own weight, especially useful when coming up steep ramps from basements or carrying groceries etc. when unfolded and walking with a friend
  • High quality, full sized crank arms and pedals that don’t flex under force and weight, I like that instead of using cheap plastic folding pedals Tern developed a quick release system for the right pedal… the bike is still compact when folded but rides much better
  • Lots of safety elements going on here, you get protective lining in the tires, reflective stripes on the side, bright lights that run off the main battery and have windows on the sides so you can be seen from more directions
  • Premium hydraulic disc brakes front and rear, these things stop on a dime and are much easier to use and pull than mechanical disc or older style rim brakes, note that the brake levers can be adjusted to be closer or further from the grips depending on your hand size
  • Ergon locking grips feel nice and won’t twist under pressure or when you’re lifting and folding the bike or crack if the bike tips, just a nice upgrade
  • The Bosch Purion display is relatively easy to read, backlit, controls the lights and is easy to reach while gripping the left bar, you don’t have to take your hand off to use it (which improves safety) but it’s very intuitive to use still, each press of the buttons delivers a nice tactile click and it has a 5 Volt Micro USB port built in for charging a phone, GPS or other portable electronic device
  • Both folding latches have a two-step unlock system so you won’t accidentally come unfolded while riding
  • I like that the seat post has clear markings on it so you can remember and re-adjust each time you fold and unfold the bike to the appropriate height
  • I think the way that they mounted the battery is wonderful, it doesn’t raise stand over height, doesn’t hang way off the back or take up rack space and can still be easily removed WITHOUT taking off the seat
  • The motor is mounted really well, it doesn’t hang down much and is protected by two tubes with plastic caps that allow the bike to rest evenly when folded… it’s one of the most stable folded electric bikes I have tried, many other designs tip easily
  • A larger chainring paired with a 10 speed cassette make pedaling feel natural, they designed it to ride like a normal full sized bicycle even though it has smaller 20″ wheels, it climbs very well and can reach 20 mph but I had to change gears to reach the top speed
  • The rear wheel dropout is raised a bit to allow for strong mounting of the disc brake and more space for the rack and fender eyeletts, I believe it also lowers the center of gravity on the bike
  • I like that both wheels feature quick release because it makes the bike easier to work on or fix flats on the go… just bring a spare tube, mini pump or CO2 in one of your bags
  • If you register the bike your warranty goes from 5 years to 10 years for the Tern frame and select components (the motor and battery are 2 years)


  • The Tern Vektron is definitely one of the more expensive folding electric bikes, it offers premium components, a first class drive system and an amazing warranty but that comes at a price
  • As with many folding ebikes, you only get one frame size here and it’s a bit longer than normal (the reach is longer), you can dial it in with the Andros stem and by sliding the saddle rails
  • While I love that the seat raises so high, it wasn’t clear how you’d be able to raise the handle bars to match without some special accessory, the Andros adjustable stem helps a lot but some other folding electric bikes have telescoping handle posts to address this
  • There’s just one color choice here, if you buy a couple of these for a his and her setup it might be tricky to tell which is which uless you add some accessories ;)
  • The stand over height isn’t super low, Tern purposefully uses a curved tubing design for strength and puts their folding joint back a bit but this means you’ll have to step higher to get on than some competing models
  • I love that they included bottle cage bosses but probably wouldn’t mount a cage and bottle here because it would be nearly horizontal and might leak, consider a folding lock, mini-pump or other compact accessory (or a tight bottle!)
  • It’s great that Tern went with wider tires for their official electric bike offering because in my experience, you tend to ride at a higher average speed and for longer distances and comfort can be an issues. Otherwise, there’s no suspension fork or seat post suspension… consider a Thudbuster or other 27.2 mm after market seat post
  • The Bosch Purion display panel isn’t removable like the Bosch Intuvia but it’s much more compact and still delivers all of the same readouts (hold + to activate the lights, hold – to cycle through menus)
  • Unlike a lot of other premium full sized e-bikes, the wires are not internally routed on the Tern Vektron (which makes folding and repairing easier) but they could get snagged easier and the front wires might interfere with the optional front rack and cargo if you remove the head badge on the head tube and install a “luggage truss” on the “luggage socket”

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