The first joke you can expect to hear about Serial 1, Harley-Davidson’s e-bike spinoff, is how Harley managed to make them set off car alarms and wake up the neighbors. As it turns out, the $3,399 Mosh/Cty is the loudest bike I’ve ever ridden. That’s a good thing, though it has more to do with me than the bike.
Full Disclosure: Serial 1 rented a minivan and drove from Milwaukee to NYC with its full range of e-bikes jammed inside. I had only a few hours before an early winter sunset, but still was able to rip around on the company’s most affordable and most expensive bikes. I brought my girlfriend’s Brooks saddle with me, and I’d recommend you do the same if you buy one of these.
Testing Conditions: Serial 1 set up its test ride next to Brooklyn’s Prospect Park, so I was able to do some sustained riding on the park’s paved loop and some more idiot-brained riding on its dirt paths. I got a sense of what the bikes are like to ride, but I’d need more time to know exactly what they’re like to live with in terms of charge. There is a jump in the park that I love dearly but joggers were blocking it every time I passed. Probably for the best.
The more expensive Serial 1s are the Rush models, which run from $4,400 to $5,000, depending on whether you get the step-through version or the one with a conventional-looking frame, and whether you go for the basic motor or the one with the higher top speed.
Somewhat confusingly, both the Rush and Mosh models offer the same power. The base motor is the German Brose S Mag, rated at 250 watts and 66 lb-ft of torque. The top-tier Rush/Cty Speed gets the Brose TF Mag, which is...also good for 250W of power and 66 lb-ft of torque. I’ve read the Brose website twice now and I still can’t figure out what the technical difference is between them, other than that the S is for “summiteers” and the TF is for “sprinters,” according to Brose’s site. These motors are produced in Berlin, and Brose happens to be the world’s fourth-largest family-owned automotive parts supplier, if you’re curious.
The motor doesn’t make these bikes feel different though. What does change the vibe is the straightforward single-speed hub that comes with the Mosh, while all the Rush models have a self-shifting enviolo hub.
That enviolo hub is a CVT, the same sort of thing as the Continuously Variable Transmission found in a Prius or a Nissan Rogue, or — as some car nerds would recall — a 1960s DAF. Bike nerds would also know enviolo as a new brand name for NuVinci. That was the first CVT bike hub, which started appearing in the pages of Popular Science and on production bikes in the mid-2000s.
In the late 1990’s, Donald C. Miller, a cycling enthusiast, became interested in building the world’s fastest bicycle. Although he had no formal engineering training, he analyzed the system components and determined that the transmission was a limiting factor. He looked around for new ideas, and came across the concept of a continuously variable transmission (CVT). Believing that a continuously variable transmission might help him achieve his objective, Don conducted a series of experiments that led him to develop a new CVT concept for use in a bicycle transmission.
I want to know everything about Don Miller! I do not, however, want to ride a Serial 1 e-bike with his type of hub. It’s certainly effective and efficient, but it’s also strange to ride.
The hub itself is doing some constant shifting as you pedal. For each bit that you speed up, the hub compensates in its gearing. Your cadence — the speed at which you are pedaling — remains the same. You hit a hill and the hub gears down. You start descending and it gears up. When you’re underway, it’s seamless and perfectly smooth.
Hop on the pedals, though, and it takes the hub a moment to catch up with your initial effort. There’s a momentary delay anytime that you really accelerate.
And that’s complicated by a second thing going on with the bike. Every time you’re accelerating, the motor is also waking up to assist your pedaling. Every delay is doubled, and I found myself repeatedly spinning out at the pedals whenever I took off on a Rush. It’s a disconcerting feeling, like the clutch is slipping in a car or like the chain has slipped off of your bike.
All the Rush models, then, are most comfortable when you’re relaxed. They go faster than the Mosh does, for sure, but they only feel slower. I pointed the Rush /Cty Speed up a steep dirt hill that the Mosh wasn’t powerful enough to climb. The Rush blitzed up it, handling wheelspin with ease. It made it, but it also made it boring.
The Rush models would love to tell you, “Please chill out a little bit.” They want you to commute; they don’t want you to go for a random rip.
By contrast, the Mosh model is down to clown. While the Rush model has two levels of added interference versus a normal bike, the Mosh takes one away. There are no gears at all, just a direct link from your pedals to the wheel through the belt drive. You do get assistance from the motor, but it feels natural. It rides like a good bike, with a lot of tire for bashing up rocky paths and strong disc brakes for descending down them.
And it’s loud. At least a lot louder than any old bike I’ve ever owned.
The hub clicks every time you let off the pedals and it’s a decently loud buzz. The sound of a hub when you let off the pedals is something that the nerdiest of bike nerds focus on. Here, for instance, is a very sweet video of the mechanics at Tokyo’s Blue Lug bike shop quizzing each other blind folded to see if they can identify various high-quality, high-performance hubs by sound alone:
Hubs work like a ratchet. When you’re pedaling, they engage and propel you forward. When you let off, they freewheel. Little pawls within the hub provide the engagement, and they click when they spin freely. A stronger hub, the Blue Lug mechanics explain, make a louder ratcheting sound. Each different ratcheting mechanism produces a different tone.
I emailed Serial 1 to see if they knew exactly how many pawls are in the Mosh’s hub, but nobody knew the exact tech specs or make and model. Still a spokesperson could explain the very good sound:
It’s a house-brand aluminum hub that rolls on sealed cartridge bearings and is fit with a single speed freewheel. I’m sorry, I’m not certain of the exact number of pawls, but it is a heavy duty/ high-engagement freewheel which is why it has the louder/higher-frequency sound characteristic of more premium bikes. The rear sprocket is 22 teeth; the front chainring is 50 teeth.
Hope that helps.
Certainly it’s not as loud as a Chris King or White Industries hub, but it’s louder than any Shimano-equipped bike I’ve ridden or built. You might not wow your BMX buddies in a Serial 1, but it will be louder than most commercially-available bikes out there.
Just like the Blue Lug mechanics put it in that video, the sound does give a good sense of quality. The Serial 1 Mosh does feel like it has quick engagement, and does feel lively as well as well-built. The hub is a part of that perception.
This is a fun bike, e-bike or not. It’s a rigid frame, but there’s a lot of cushion in the rather airy Schwalbe 650bx48 tires. There’s a decent amount of grip from them, too, and I spent most of my time pretending the thing was my ’80s mountain bike. I wasn’t even all that troubled that the Mosh weighs fully two times what my horrible old Schwinn weighs — it comes in at 48 pounds. That makes it more than a small chore to carry up a flight of stairs. With its good brakes and good gearing, though, it doesn’t make for a soggy bike. It’s fun to ride in spite of the weight, and you want to huck the thing.
While the Rush models get a somewhat trick display screen for battery, range and other info, the Mosh just gets a simple clicker for more boost or less. It’s not intrusive, and helps the Mosh feel more like a bike and less like an appliance.
It does rip, though. The Mosh will shoot up to 20 mph with full assist, but I still found myself working up a sweat on it. I just liked jamming on the pedals.
It still cracks me up that the hub is good and loud. It’s a nice note that Harley ended up making not just a good-quality bike, but one that lived up to its experience and reputation.