Harley-Davidson Serial 1 Ebikes: MOSH/CTY and RUSH/CTY Speed Review - First Ride

Mark Cernicky
by Mark Cernicky

Harley-Davidson returns to its powered-bicycle roots

“E” for ETHOS is in the air, people are starting to take action instead of just saying they care about the atmosphere. Purchasing electric cars, reusable grocery bags, cups, paper straws, and the repurposing of man-made matter; recycling is on the rise everywhere. Serial 1 ebike is Harley Davidson’s delve into the e-ssisted bicycle – announced in November of 2020. It’s also a clear connection to the re-cycling of heritage, since Harley’s first motorcycle ever is referred to as Serial 1. Harley-Davidson’s engineering strength, production prowess, and resources reaped from the love of feeling the freedom of two-wheeled mobility inspires the clear connection between Harley-Davidson motorcycles and its brand new bicycle brand. In fact, Serial 1 is now its own Lehi, Utah-based company, with H-D holding a large part of the equity.

At the museum: “Serial Number 1,” the oldest known Harley-Davidson motorcycle, c. 1903. Y’know, it actually does resemble these bicycles more than any modern Harley.

Now a full line of ebikes have been designed to be ridden, recreationally and or daily, answering a new generation’s call for a viable eco-friendly health-conscious mobility choice. Also quite a few members of a more mature generation, including Burns and me a couple weeks ago, when famed former motojournalist and current Serial 1 Product Manager Aaron Frank dropped by with a pair of pre-production Serial 1s for us to sample: a MOSH/CTY and a RUSH/CTY Speed. The /CTY suffix, Aaron scoops us, indicates that these bikes are all part of Serial 1’s “city” platform, while also suggesting that other platforms might be on offer in the future. (Also, when all the good names are already taken, tacking on /CTY opens up a whole new world of possibilities.)

MOSH/CTY, left, and RUSH/CTY Speed on the right

Harley-Davidson Serial 1 ebikes

Your MOSH is the more economical hooligan of the two, a stripped-down single speed. It’s the ultimate urban playbike, says Aaron and S1, “designed for trend-setting adults seeking a stylish and flexible way to move around their fast-paced urban environments.”

The RUSH, as you might gather from its full fenders and cargo racks, is “the sophisticated commuter… a premium, full-featured eBicycle designed for more convenient and fun commutes. The easiest, most intuitive way to get anywhere, without breaking a sweat.”

To MOSH or mush? That is the question.

Automatiq hubbub

You can indeed break a sweat on either one, but it’s not required. Both ebikes are powered by 250-watt Brose motors (the MOSH a TF-mag and the RUSH an S-mag) that produce 66 ft-lbs torque. Careful on that first pedal push if you’re on a loose surface; you can peel right out. The MOSH battery is 529 watt-hours while the RUSH is 706 Wh, which gives it a bit more range; MOSH is supposed to go 35 to 105 miles, depending, and the RUSH 35 to 115 miles. We pedalled about 15 miles, and still had 75% juice remaining according to both bikes’ electronic instrumentals. Supposedly you can get a full charge, from 0 to 100%, in 3 to 5 hours from your 110v outlet.

The biggest difference between the two bikes is the RUSH’s Enviolo Automatiq intelligent auto-shifting hub. Whaaaaa?? This thing is a mini electronically controlled, constantly variable transmission inside the rear hub, that – just as the CVT in a scooter lets the engine operate constantly at its favorite rpm – lets you pedal pretty much constantly at your preferred cadence, from 0 all the way up to 28 mph – a speed that puts the RUSH in the Class 3 ebike category. (There’s a Class 1 non-Speed RUSH also, that only goes 20 mph.)

Enviolo Automatiq hub is genius; built-in LED brake/ taillights are very bright even in daytime. 203mm hydraulic disc brakes front and rear are good to have on bikes this speedy.

Who knew that’s why racing bicycles have 21 or more speeds? It’s so the rider can keep pedaling in their sweet spot all the time, like 90 or 100 rpm for professional racers. More like 45 to 60 for most of us. You can adjust the cadence via the Enviolo app, which connects to the hub via Bluetooth, to find what speed your legs like best. Wherever it was set the day we rode, the bikes seemed to agree with both of us.


The MOSH, meanwhile, makes do with its single-speed hub. By the time you’re at its 20-mph top speed, you’re pedalling about as fast as you can unless you’re Lance Armstrong, but you’re also getting plenty of boost to help you do it – and pedalling faster is better for you than pedalling slower, according to the experts. It’s not hard to keep up a steady 20 mph on the MOSH. It is hard to watch Burns power away from you on the RUSH. The MOSH does weigh 11 pounds less than the RUSH, though, in the official specs, 48 lbs vs. 59.

Frames are welded hydroformed aluminum, light and rigid. Batteries pop right there into the bend, for good mass centralization and handling, and can be charged in or out of the bike.

Both bikes get swell little Kevlar belts that’ll never need adjusting, and both are turned out with a level of paint and fit-and-finish that makes them worthy of their H-D livery. Brake and electrical lines are routed internally through handlebars and frames.

Let’s Pedal

Cernicky: Serial 1’s “Intelligent Sizing” means that each of the four frame sizes has a unique geometry crafted to optimize rideability, and thanks to a standard-type upright riding position, our range of test riders remained comfortable and wouldn’t have objected to riding the rest of the day. Controls were ergonomically tax-free on our digits.

Easily adjustable seats feel comfortable to the pants even without chamois in your shorts. The padding and width of the perch causes no inhibition of leg travel when churning out mileage. My feet didn’t slip off the pedals even when pedaling up a steep hill no-handed.


The stout single-speed is built for hooliganical work; it’s stark raving, yet feels so solid and sure footed. Yes, kinda heavy, but even without suspension the wide SuperMoto tires stay seated with only 18 psi – which lets the sidewalls damp out terrible terrafirma, climb stairs, and jump curbs found in our uber-urban atmosphere. There’s plenty of Umph to climb the steepest grade in Sport mode with no hands. And after some lunacy along our 15-mile loop, only 25% of the full charge had been dispensed.

Barbarians at the Gate

The size Large Mosh, though, was too big for me. Nice to ride on the road, but any kind of bump jumping or wheelie popping and I’m sure my 5’7.5” self would have been better off on the medium-size framed version. Of course, with more time on this one – size M – I would raise the gearing so I could go faster.


The constantly variable transmission fits into the hub to sync with its rider’s cadence and maximizes human-powered torque input perfectly meshed with e-ssistance output to deliver a very enjoyable blend of exercise and getting somewhere, no sweat. This thing is an amazingly efficient transformer of pedal depression into good-times per revolution to make commuting fun (GTPRTMCF). Or even just riding around the back bay with no particular place to go like we did.

It’s a social thing too. Where once we spent our two-wheeled lives locked inside our own helmets seeking speed, glory, and whatever else we were after, on these ebikes, well, we’re still after it. But now we’re not going so fast we can’t stop or at least slow down to sniff the spring daisies and duck guano.

It’s a family affair. Daughter Maely Cernicky, 5-feet-Zero and 12 years old, got in a quick pedal on the midsize RUSH/CTY Step-Thru, also equipped with the Automatiq hub: “I like how you can adjust the settings based on how hard you want to pedal. Sport was my favorite setting, fast but stable and comfortable. And I liked the glossy white finish and shield light, I really enjoyed it.”

Ever tried to pedal in sand? Fat tires and Brose propulsion make it easy.

What Burns thinks, not that anybody cares:

This is only my second brush with ebikes, so I’m far from expert. But these H-Ds are definitely different than the Yamahas we sampled before. The Yamahas felt more like really swift bicycles, the Harleys are quite a bit further along the motorcycle spectrum: pretty sure they’re substantially heavier than the Yamahas, yet with more e-boost to offset the mass.

2018 Yamaha EBikes First Ride Review

Riding my Specialized hybrid (before it got stolen) or my trusty/crusty beach cruiser (nobody wants it) this same 15-mile loop around the back bay, I’d need a couple cold drinks and time on the couch to recuperate afterwards. But on the Serial 1s, Cernick and I both could’ve done another couple laps before beveraging, since these things carry their own fountain of youth. You still get a workout, but you can cover way more ground in the process; they’re almost as freeing as being on a motorcycle. And fast enough that my motorcycle traffic strategy still applies: It is better to come up behind your prey than to not know what might be gaining on you.

I know where the hills are on this back bay route, and my ventricles quiver in fear at every approach: On the Serials, you lean into the pedals a bit and find yourself at the top, panting and sweating just enough to make you feel good (just barely in my case). Both my old Specialized and the Yamahas impressed upon me, quite literally, the worth of those padded bicycle shorts. I dragged them from the dresser that morning to ride the Serial 1s, and the other children all laughed at me. The seats on these may look racy, but they’re made for pedaling in regular clothing.

No animals were harmed in taking this Rollie Free tribute photo except Cernicky. Ouch.

The Automatiq-hubbed RUSH/CTY Speed is the Bomb, since it’ll go that much faster, 28 mph, and finding your body’s natural cadence is probably a really good thing. My legs felt good whatever we had programmed in there, I think 50-something rpm. Like everything in the modern era, you’ve got four ride modes: Eco, Tour, Sport and Boost provide incrementally increasing assist; toggle through on the fly as needed. (There’s also a Walk Assist mode, if you wind up taking the walk of shame.)

It’s a dreamy feeling to start off from a dead stop, and quickly be going that fast without ever pedaling any faster. But 28 mph on a bicycle feels almost too fast; I only topped it out a couple times for the sake of science, and decided I liked the cheaper, 20-mph MOSH just fine, too. The MOSH’s single speed is a bit more work and feels more bicyclish, but it still packs plenty of epower. Twenty mph doesn’t sound like much to us motorcycle people, but on a bicycle it usually feels like enough, especially on a bike path with lots of kids and dogs. Since I’d only be riding for fun and have no commute, and since I’m cheap, the MOSH would probably be my choice. (Come to think of it, I’m starting to miss my commute; it used to mean riding motorcycles every day).

Admittedly we didn’t go far, but I could’ve done another 15-mile lap. I’m not so sure about Cernicky, who can’t not revert to his BMX childhood whenever the opportunity comes anywhere near presenting itself, in spite of a pair of damaged ankles that had him couch-ridden for a couple of years not so long ago.

Repeatedly hucking the MOSH in the air for several passes for the camera was above and beyond the call of duty (more the landings really), but it had us both laughing like little kids, even if it had MC on the Advils the next day. I think that’s what it’s all about, am I wrong? If you have a good place to ride a bicycle, these things are irresistible. They remind me of the Hodaka Combat Wombats and things the cool kids rode illegally in the woods when I was a kid.

Cernicky concludes:

The new age is waking up to the beautiful concept of getting exercise while feeling the freedom of e-bicycles. Don’t trust me, give them a try yourself before batting your eye at the price tag. Speaking of price tags, in spite of the fact that these wear Harley-Davidson branding, along with various high-end components and high-brow H-D engineering – the prices are totally in line with what you’d expect to pay for any premium, non-rattletrap eBike. The structural integrity is in place. Put the price tag up against: car or motorbike cost, gas, maintenance, insurance, parking, gym membership, special vitamins… and the savings might surprise you.

Four Serial 1 bikes are going into production, and will begin rolling out soon:

MOSH/CTY, $3,399 single-speed urban playbike (Class I, electric assist up to 20 mph),

RUSH/CTY, $4,499 full-featured commuter with auto-shift CVT hub (Class I, electric assist up to 20 mph)

RUSH/CTY Step-Thru, $4,399 with auto-shift CVT hub (Class I, electric assist up to 20 mph)

RUSH/CTY Speed, $4,999 with auto-shift CVT hub (Class III, electric assist up to 28 mph)


Interested in the Serial 1, Join our Serial 1 Forum.

Mark Cernicky
Mark Cernicky

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2 of 96 comments
  • Mark Mark on Mar 20, 2021

    It just needs some playing cards in the spokes to make it sound like a Harley.

  • Robert Crawford Robert Crawford on Aug 31, 2021

    I know this is a few months old, but I am seriously looking that the Rush-Speed. I currently ride a home built eBike with a mid power mid-drive. What do I expect to get for the cost difference?

    First, a halfway decent homebuilt is going to cost a couple thousand, all in.

    I expect to get a motor that is supported. I can go online and order just about any part in a Brose motor. That isn't true with may of the motors used in homebuilts, and even many other turnkey ebikes.

    The Serial 1 is a very clean looking bike. I am talking about the decision to internally route whenever possible. It also offers several different sizes. Many turnkey eBikes are one size fits none.

    I have had belt drive bicycles and love the concept. My current belt drive bicycle is no loan to a family member, I gave her that one because of the lack of any real maintenance needs. However, belts have benefits beyond that. If you douby, try a similar bike with belt , and one with a chain. The belt is a better ride for nearly all (not quite all, but nearly). I can say the same about the CVT hub. I have one on my current eBike and have had them on other bikes as well. Sure, there are a few places where they are not the best, but those applications are few.

    My application is a simple five mile commute and errands. Reliability matters a lot more to me than range.

    In one of the posts, someone asked about regeneration. In general, regen doesn't do a lot for eBikes, they are just too light. However, there is another issue, regen only works with hub mounted, direct-drive motors. In a mid-motor the freewheel happens before the motor. Thus, no regen.

    So, we are at: support, style, fit, and components. Yes, there is probably one in my future