Tern Vektron S10 Review | EBR First Impressions

The Vektron is the only Bosch-equipped folding electric bike sold in North America, a fact that Tern is rightly proud of.

Bosch makes arguably the best e-bike drive systems on the market, and the Performance Line motor spec’d on the Vektron S10 is a cornerstone in the Bosch lineup. But the Vektron’s strengths don’t stop at its motor. Tern managed to design a folding bike that’s balanced, efficient and feels incredibly solid.

The Vektron’s Bosch motor and Shimano drivetrain.

“It’s not easy to make a good riding folding bike, a good looking folding bike,” said Dale Aguas, Tern’s North American territory manager. “It’s basically: Hey, make us a really nice bike, make it small, make it fold and make it one size. Bring that to the average product development team and they’re going to flip out. To do that and to integrate a Bosch system is quite difficult, but we’re experts in folding, we’re experts in small wheels and we have the patents on folding geometry — we know what it takes to make a small bike feel like a big ride.”

The Bosch Performance Line Class 2 motor powered by a PowerPack 400.

Tern equipped the Vektron S10 with the Bosch Performance motor that offers up 65 Nm of torque and is powered by a 400Wh Bosch PowerPack. This is a Class 1 e-bike, so it’s maximum pedal-assisted speed is limited to 20 mph.

The Performance Line motor had plenty of oomph to handle the hilly roads in Park City, and the relatively modest 65Nm of torque produced by the Performance Line motor was plenty for the smaller bike.

Transferring power from the cranks to the rear wheel is a Shimano Deore 10-speed groupset, delivering crisp and reliable shifting performance.

The Deore groupset is from Shimano’s mountain bike lineup but we’ve seen it more and more on higher-end electric commuter bikes. Not only does Deore employ a chain stabilizer to keep the drivetrain quiet and controlled, it seems to handle hard shifts under load very well — an important feature on an e-bike.

Brakes: Magura MT4

The Magura MT4 rear brake lever.

Slowing the Vektron S10 down is a pair of Magura MT4 hydraulic disk brakes.

The MT4 is a dual piston all-rounder brake designed for use on pavement and trails, and they proved plenty powerful on the steep, twisty descents in Park City. The Vektron handles well enough that I was comfortable carrying a lot of speed into corners and the MT4’s were a nice safety net when I bit off more speed than I could chew.

Other notes: A burly racking system and a keen eye for little details

The Vektron S10 is flush with extras, but the two I’m going to focus on here are a rear rack that maximizes this small-ish bike’s carrying capacity and an innovative adjustable cockpit that makes the bike easily shareable.

Bolted to the back of the bike is Tern’s burly Atlas V rack that has a 60 lb carrying capacity and a mounting system that works seamlessly with Thule Yepp Maxi and Nexxt Maxi child seats, so you can take your little human with you. That pannier-style mounting system is also compatible with a host of other bags and racks.

Tern’s telescoping seat post makes it easier to swap between riders.

Tern also outfitted the Vektron with its innovative Andros stem that easily adjusts height by way of two quick release clamps, making it easy to adjust the fit between two different size riders. The Vektron also features Tern’s telescoping seatpost, which uses two quick release clamps instead of one to add another element of adjustability that makes the bike more easy to share.

I could do an entire post about all the little details and added extras that make Tern’s Vektron S10 one of the coolest, most useful and best riding folding e-bikes on the market, but this is supposed to be a short review, so we’ll save that for another time.

I’ll try to sum it up this way: Tern takes an incredible amount of pride in their bikes. They are die-hard bike riders building bikes for die-hard bike riders, and the dedication to their craft shows. The product team at Tern spends so much time riding their bikes they’ve thought up solutions to problems the cycling world wasn’t yet aware needed fixing; storage solutions, folding solutions, racking solutions — the list goes on. It only makes sense that they’d take an idea as complex as a folding bike and refine it into something that feels much simpler and much more put together than some of their competitors.

Priced at just shy of $4,000, the Tern Vektron S10 is a transportation investment, but it’s one that won’t let you down. It’s hard to understate the value of the Bosch drive system and the sheer depth of engineering that’s gone into Tern’s bikes, and the Vektron is an electric folder that’s built to last.

Tern sells the Vektron S10 through its national network of dealers dotted across the U.S. Or, you can also buy the bike online through REI and have it shipped to your door by clicking the button below.