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Propella 9S Pro V2 Spec Review 2024
Jan 21, 2024
Propella has announced the second generation of their 9S Pro model, the 9S Pro V2. This is a Class 1 commuter (20 mph max speed, no throttle) that comes in both a traditional frame as well as a step-thru frame. The Propella 9S Pro V2 is unusual among e-bikes in this value-focused tier of e-bikes. It retails smack-dab in the middle of the $1000-$2000 price range, but it sports a collection of features that would be more in keeping with an e-bike priced above $2000.
The Propella 9S Pro V2 is light for a commuter e-bike, weighing just 43.5 lbs., which is an impressive achievement for any e-bike. They manage this by making a number of strategic choices with regard to components. First, there’s the 350W brushless, geared hub motor. As we’ve mentioned in reviews of other sub-50-lb. e-bikes, when an e-bike weighs less than 50 lbs., a smaller motor (like this 350W unit) can offer terrific performance because it doesn’t have to accelerate as much weight.
A 350Wh battery powers the Propella 9S Pro V2, which is more effective than it might seem at first glance. More on this in a bit. It’s equipped with a 9-speed Shimano drivetrain, hydraulic disc brakes, 27.5-in. wheels running 2-in.-wide tires and an adjustable stem to dial the fit. Possibly the most surprising detail of this e-bike (aside from its weight) is the fact that it is equipped with a torque sensor.
What’s it all add up to? Let’s have a look.
Propella 9S Pro V2 Spec Review: Bike Overview
Commuter e-bikes have a different set of priorities than some other e-bikes. They need to be efficient; that is, they need to cover as many miles as possible with each watt/hour of capacity the battery offers. Features that will help increase an e-bike’s range include less weight, and bigger wheels.
Anything less than 50 lbs. is cause for celebration where an e-bike’s weight is concerned. The 43.5-lb. weight of the Propella 9S Pro V2 makes it one of the lighter commuter e-bike’s we’ve seen.
The Propella 9S Pro V2 rolls on 27.5-in. wheels, which is the next-to-largest wheel size available (700C or 29-in. being the largest). Larger wheels offer lower rolling resistance, which is to say that once they are up to speed, they are easier to keep rolling. A wheel’s size is only part of what determines the rolling resistance, though: tires matter, too. The wheels are shod with CST Brooklyn 27.5 x 2-in. tires. This is a low-profile tread with small sipes (or channels) to move water out from under the tires. It’s a tire big enough to offer a comfortable ride while still maintaining a high level of efficiency.
Propella includes a nice array of accessories to make the 9S Pro V2 commute-ready. It comes with full fenders front and rear, as well as a front light and kickstand. Yes, they left out the rear rack which is a common feature on commuters, but a rack adds weight and many commuters wear a backpack rather than mount a pannier or two. Not only does not adding a rack keep weight down, but obvs, it helps keep the price down and is a component that can always be added later.
Propella 9S Pro V2 Review: Specs & Features
Frame and fork
The frame and fork are made from 6000-series aluminum. This is yet another way Propella helps keep the weight down on the 9S Pro V2. While aluminum frames are the rule rather than the exception in this price range, we often see a suspension fork and in this price range, a fork with a steel coil spring will add pounds to the e-bike.
Propella produces the 9S Pro V2 in both a traditional frame and a step-thru version. Often, when we see two different frame designs, the sizing won’t change, but with the Propella 9S Pro V2, the traditional frame features a 60cm-long top tube, while the step-thru frame features a 58.5cm-long top tube, making the step-thru appropriate to smaller riders, as it should be.
Motor and battery
Propella chose a 350W brushless, geared hub motor that produces a maximum power of 500W and 40Nm of torque. In absolute terms, this is a rather modest hub motor, but that doesn’t hurt this e-bike for a number of reasons.
First, as we mentioned, this e-bike weighs just 43.5 lbs., so a smaller motor can make a bigger impact than if it was mounted on an e-bike weighing 70 lbs. Second, this is a Class 1 e-bike, which means it has a 20 mph maximum assist speed and no throttle. A Class 2 e-bike needs to be able to accelerate up to cruising speed with no help from the rider when they use the throttle. That’s not an issue for the Propella 9S Pro V2 because it lacks a throttle. And then there’s the torque sensor.
A 350Wh battery also seems small, but battery performance can’t be judged on its own. To understand how much range a battery might offer, we have to know how powerful the motor is. Our rule of thumb for acceptable or even respectable range from an e-bike is to see a 1:1 ratio of motor power to battery capacity, which is what we see here with the Propella 9S Pro V2’s 350Wh battery. Propella estimates that the e-bike will offer riders as much as 55 mi. of range per charge.
A torque sensor makes the motor more responsive. As soon as the rider starts pedaling, the motor kicks in; there’s no delay as happens with a cadence sensor. The presence of the torque sensor means the motor’s operation runs seamlessly with the rider’s pedaling, that as the rider pedals harder, the motor’s output climbs, and vice-versa.
E-bikes going for less than $2000—and we’re referring to even those that retail for $1999—rarely come equipped with a 9-speed drivetrain. That’s the mark of a more expensive e-bike. The rear derailleur and cassette come from a new-ish (they were launched more than a year ago) group of parts from Shimano called Cues. It features an 11-36t cassette, which gives riders a wider range of gears with smaller steps between the gears.
Shimano’s Cues parts were made specifically for the rigors of e-bikes, where the extra torque of an electric motor can cause rapid wear on drivetrain components. Cues is meant to shift more smoothly and last longer than Shimano’s Tourney, Altus and Acera groups.
Propella also chose hydraulic disc brakes for the 9S Pro V2. The brakes are paired with 180mm rotors to offer plenty of braking power.
The alloy handlebar from Zoom features some rise to allow the rider to sit more upright as they ride, making it easier to look around. And they included an adjustable stem which will allow riders to adjust the e-bike to their comfort.
EBR’s Propella 9S Pro V2 First Look Review:
The difference between an e-bike with a cadence sensor and one with a torque sensor is significant. There’s not another component that can do more to change the fundamental personality of an e-bike than by replacing an inexpensive cadence sensor with a more expensive and sophisticated torque sensor. That doesn’t automatically make a torque sensor better, but it is noticeably different.
For the rider who wants a motor to assist them, but they don’t want to be reminded constantly that a motor is helping them, an e-bike with a torque sensor is the way to go. Cadence sensors cause the motor to operate more independently, turning on and off a second or two after the rider starts and stops pedaling. For that reason, e-bikes with a cadence sensor tend to feel more impressive with a bigger motor. With a torque sensor, the motor’s operation seamlessly melds with the rider’s pedaling, making the rider feel more like a superhero.
For some riders, a torque sensor may not be the way to go. That’s because to reach top speed, the rider is going to have to make a real effort. An e-bike like the Propella 9S Pro V2 won’t hit top speed without some pedaling, whereas a cadence sensor only measures whether or not the pedals are turning. For the rider who wants some activity, not a workout, an e-bike with a cadence sensor can be the more appropriate choice.
The Propella 9S Pro V2 is an impressive e-bike and is proof that as new technologies come out, prices come down. A year ago a sub-$2000 e-bike equipped with a torque sensor and 9-speed drivetrain was unthinkable. Now, it’s downright affordable. And considering the way many of these consumer-direct companies will discount their e-bikes (especially during the winter), any sort of sale will make the Propella 9S Pro V2 feel like insider trading. We can’t wait to perform a full test on this e-bike; we’re that impressed.