By 
The Takeaway: Clean looks and a great motor combine for an impressive mountain bike from Serial 1.
- Brose motor with 90Nm of torque.
- Integrated head and tail lights, with light-up head badge.
- Custom battery pack sits very low in the frame.
- 430Wh battery standard. Optional 706Wh battery.
Price: $4,500
Weight: 53.0 lbs. (Large, claimed)
If you’re shopping for an e-bike today you have options. Lots of options. And while there are plenty of e-bikes to choose from, there are also a lot of unproven players and some downright sketchy actors. Serial 1 is a new e-bike brand, but after riding its latest Switch/MTN model, we’re prepared to say this brand is legit and offers a high-quality product. Perhaps that’s because, though Serial 1 is a new name, its origins go back to a 121-year-old attempt at building a motor bicycle.
More From Bicycling
Who The Hell Is Serial 1?
Although it seems like it sprung from nowhere—like many recent e-bike brands—Serial 1 has strong roots in two wheels. Serial 1 is an offshoot of Harley Davidson; the brand name is a reference to the oldest H-D motorcycle which resides in the company’s museum in Milwaulkee and is nicknamed “Serial Number One.”
Like a lot of the early motorcycle brands, Harley Davidson’s origins have a bicycle connection. In H-D’s case, it was when William Harley designed a motor intended to be fitted into a bicycle frame (which he eventually did with the help of the Davidson brothers). The result was, to use the parlance of the time, a “motor-bicycle” that was ultimately deemed unsuccessful. But it was the beginning of the Harley Davidson we know today.
Serial 1 began in 2018 as a “skunkworks” project at Harley Davidson and has some personnel ties to H-D’s LiveWire electric motorcycle. In 2020, the brand launched with city and commuter models but continues to expand its line. The most recent model is the Switch/MTN you see here.
Closing the loop on the brand's origin, Ser1 started off as an e-bike business unit within Harley Davidson but was recently spun off as a separate entity (although Harley remains Serial 1’s parent). And in a pretty neat way, Serial 1 is a return to Harley’s origin.
Serial 1 Switch/MTN Motor and Battery
Though Harley Davidson is often called The Motor Company, Serial 1 did not design its own e-bike drive unit. Company representatives hinted that an in-house motor project might happen someday, but for now, they’re turning to established players in the space.
Serial 1 uses Brose drive units: The Switch/MTN gets the Brose Drive S Mag with a healthy 90Nm of peak torque. If the name Brose rings a bell deep in your cranium, it is because Specialized’s Turbo e-bikes run customized Brose motors. The motors are well regarded for their smooth and quiet operation. However, there have been some notable reliability gremlins that everyone (of course) swears are handled. We hope so because it is one of the very best e-bike motors we’ve sampled.
Serial 1 uses Brose’s compact Display Remote for information and control. Colored LEDs provide basic battery and assist status; if you want greater detail and more features, you need to use Serial 1’s smartphone app (for iOS and Android). It offers a more detailed dashboard, as well as navigation developed in partnership with Google (Google is a “strategic technology investor” in Serial 1). The app also lets the rider take advantage of the bike’s built-in security features. These include a lock, assist deactivation, and pinpoint location (the bike has its own cellular chip which remains powered even when the battery pack is out of the frame). Serial 1 partnered with Quad Lock for on-bike mounting of a smartphone, and there’s a USB-C cable so you can keep your phone battery topped up from the bike’s battery.
Serial 1’s bikes use a custom-shaped battery pack that sits as low as possible, lowering the bike’s center of mass. Instead of a long battery housed in the down tube, Serial 1’s battery is somewhat nestled into the belly of the frame, both on top and in front of the motor. It can be easily removed from the frame for security, or to swap in a different battery (all Serial 1 bikes use the same battery packs). The Switch/MTN’s stock battery is 529Wh, but the company’s larger 710Wh battery drops in for more range.
Serial 1 Switch/MTN Frame Details
The Switch/MTN's hydroformed aluminum frame shares styling with the other models in the Serial 1 line. It has a massive downtube and elevated chainstays with the motor mounted underneath, while the straight and uninterrupted seat tube allows the use of longer dropper posts. Hoses, housing, and wiring are as internally routed as possible for a clean profile. There are integrated tail lights in each dropout with accelerometer-activated brake light, an integrated headlight, and a light-up head badge for extra flair. There are also rack and fender mounts for riders who want to add some utility to the bike.
The Switch/MTN rolls on 27.5" wheels, chosen to give the bikes a snappier feel than they would have with larger, heavier, 29-inch wheels. Serial 1 offers four frame sizes—small through extra-large—but the company does not publish a detailed geometry chart. Instead, they offer very basic sizing information—reach, stack, stand over, bar width, and wheelbase—and encourage riders to use the size calculator on the Serial 1 website. It offers a frame size suggestion based on a rider’s inseam, arm length, and height. More experienced cyclists will likely find the lack of geometry information frustrating, but Serial 1’s representatives insist this is an easier and less-overwhelming sizing story for the general population the brand is targeting.
Serial 1 Switch/MTN vs the Competition
At $4,500, this Serial 1 fits into a more-premium price bucket that lands above the cheap e-bikes from Aventon, Rad Power, and the like. At this price, it’s squaring off against premium bikes like the Specialized Turbo Tero 5.0 ($5,000), Trek Powerfly 4 ($3,850), Scott Aspect ($4,000), Norco Charger VLT ($3,999), and Rocky Mountain Growler Powerplay ($4,199).
Even in the face of this stiff competition, the Serial 1 acquits itself well. The Serial 1 build kit features a 12-speed SRAM Eagle drivetrain; TRP four-piston brakes with 203mm rotors (in heavy-duty 2.3mm thickness for extra heat capacity); a 120mm travel SR Suntour Zeron fork with 35mm stanchions, boost spacing, air spring, and adjustable hydraulic damping; Michelin e-bike rated tubeless tires on tubeless-ready rims; a dropper post; and that powerful and smooth Brose motor. In total, it is a stronger build than its competition.
The knock against the Serial 1 is the somewhat small 529Wh battery. Some of its competitors come with larger batteries: The Turbo Tero’s 710Wh battery is a lot larger. Serial 1 also makes a 706Wh battery that will drop into the Switch/ MTN, but you’ll need to pay for the pleasure. Serial 1 did not provide a price, but large and high-quality e-bike batteries typically cost $750 to $1,000.
Serial 1 Switch/MTN Ride Impressions
I had an opportunity to spend a few hours riding a Switch/MTN on Bentonville’s famous trails. Overall, I came away impressed with this new player.
The attention to detail is up to par, and it is a good-looking and well-finished bike in person. I found the top three-quarters of the bike attractive, though I don’t love the way the motor appears to dangle from the frame.
But though it dangles, it is a superb e-bike motor: Smooth and very quiet, with plenty of punch as it evenly rolls out its power. It is tractable in technical and low traction situations but still slingshots the rider up climbs with authority. I applaud Serial 1 for not going hog-wild with displays and other gadgets. The bike's slim remote gives you all the control and information necessary. And if you want more data, you can use the Serial 1 app or pair a compatible cycling computer.
Though the geometry wasn’t given, the handling felt well-balanced. If anything, it falls slightly to the stable side of the handling spectrum, but it’s no enduro sled that needs high speeds before it comes alive. It felt natural at lower speeds and doesn't need a heavy hand to steer. The smaller 27.5" wheels likely help here, though there is a tradeoff on rougher terrain where the stout frame does transmit a fair amount of shock to the rider.
That said, the 120mm SR Suntour fork on the front worked well—far better than the forks I usually experience on e-bikes at this price. The chassis is appropriately stout, and the spring and damper perform well even when pushed in rougher terrain. I was also impressed with the Michelin tires—which are a very rare bit of spec these days. They offer excellent grip and predictable breakaway on a variety of trail surfaces. Even the no-name seat was nice: Supportive, comfortable, and not overly soft.
The world is awash in new e-bike brands popping up to take advantage of burgeoning sales in this newer category. But in this sea of lookalike e-bikes and some downright crap, Serial 1 stands apart with a unique story and highly refined product. Although it’s now detached from Harley Davidson, in a way Serial 1 is (120 or so years later), the realization of Willam Harley’s original “motor-bicycle” idea designed to, in the words of Arthur Davidson, “Take the work out of bicycling.”
A gear editor for his entire career, Matt’s journey to becoming a leading cycling tech journalist started in 1995, and he’s been at it ever since; likely riding more cycling equipment than anyone on the planet along the way. Previous to his time with Bicycling, Matt worked in bike shops as a service manager, mechanic, and sales person. Based in Durango, Colorado, he enjoys riding and testing any and all kinds of bikes, so you’re just as likely to see him on a road bike dressed in Lycra at a Tuesday night worlds ride as you are to find him dressed in a full face helmet and pads riding a bike park on an enduro bike. He doesn’t race often, but he’s game for anything; having entered road races, criteriums, trials competitions, dual slalom, downhill races, enduros, stage races, short track, time trials, and gran fondos. Next up on his to-do list: a multi day bikepacking trip, and an e-bike race.
