Stromer ST1 X Review

The Stromer ST1 X is really a stripped down ST2… it’s built around the same frame, a very similar motor and uses the exact same battery, albeit lower capacity. For a price, you can upgrade the capacity to match either the ST2 or ST2 S which might be useful for distance commuters or people who want to ride with full power at top speed frequently. Stromer estimates up to 80 miles per charge but that’s for a 170 lb rider on a smooth street using the first level of assist. In practice, I rarely ever use the lowest assist level with this bike because it’s heavier and less peppy than competing bikes. Relying on a TMM4 torque sensor and a gyroscopic accelerometer, the bike is responsive but performs best with slow powerful pedal strokes. For me, as someone who likes to spin, this took some getting used to and there’s a wall at the higher speeds where you have to exert yourself and then BAM it really kicks in. It’s an active electric bike, a speed pedalec capable of 28 mph top speeds and one of the more stealthy and cool looking designs out there. I frequently hear the phrase “Stromer killer” when other companies share their street bikes with me and yes… they have larger tires, integrated batteries, fenders and a rack usually. Sometimes they even have integrated lights! But I haven’t really found a worthy opponent for this niche yet. The other bikes usually cost less but their fenders aren’t as nice, the frames and forks don’t blend perfectly and the drive systems aren’t as silent or sophisticated. This is an electric bike with regenerative braking, wireless GSM software updates, app-based locking and GPS theft recovery. It’s a street bike with thru-axles on both wheels and 180 mm hydraulic disc brakes and it comes in three sizes with a 17″ mid-step for people with shorter inseams. Finally, it comes in three beautiful colors and offers an impressive two year warranty. To compete with the imitators of the ST1 and newer ST2 products, Stromer has introduced this new X model at a much lower (though still relatively high) price point.

Driving the ST1X is a brand new hub motor called the Cyro Drive. It looks about the same as the older Syno Drive used on the ST2 and ST2 S but is rated for lower torque at 35 Nm vs. 40 Nm. I rode the ST1X back to back with the ST2S and they felt similar. Both were silent and offered regen… but I didn’t have an opportunity to weigh the motors side by side or really get that up-close look I’d need to make further claims. From a marketing perspective, I imagine the motors are the same but one has been nerfed a bit to create levels and justify a higher price point with the ST2. Whatever the case (and I welcome your feedback and data) this is a gearless direct drive motor from Ultra Motor that’s larger, heavier and tougher than a 500 watt gearless equivalent. And if you’re riding unassisted, it’s going to create some drag due to cogging. That’s the downside to having regenerative braking but it’s not really a deal killer. These days, many companies are switching to mid-drives (including Specialized with their upcoming Vado street model). There’s something to be said for the integrated look, improved balance and separation from wheels as well as the efficiency gained from leveraging the cassette to optimize motor performance… but the trade off is that those systems wear the chain, sprockets and derailleur much quicker. With the Stromer bikes, motor power is independent from shifting and you’re not going to mash gears as much. My friend Chris Nolte from Propel Bikes in NY described the sensation of the Stromer bikes as more of a boost or push from behind than what the mid-drives offer. I found that it cut out less responsively when I eased off pedaling, likely to reduce the feeling of surge with each pedal stroke, so overall it feels fluid but when you really put your legs into it, the bike responds quickly and that’s very satisfying.

Powering the ST1 X is a 48 volt, 12.8 amp hour battery pack that slides into the downtube from the left side. It has an EnergyBus charging port at the base which is replicated on the outside top left area of the downtube so you can charge the pack on or off the bike easily using the exact same 2 Amp charger. Now be careful with the little black cover on the outside EnergyBus port because I frequently see this missing on demo bikes. Some ebikes now offer 3, 4 and even 5 Amp chargers which would fill faster but I wasn’t able to confirm the exact time required here given the lower 2 Amp rating. What I do know is that you can upgrade the pack from stock 618 Watt hours to 814 Wh or 983 Wh if you’re willing to pay. This is one way to approximate the ST2 and ST2 S which cost $7k and $10k and have that torquier motor. I like that their battery packs don’t latch onto the side door the way the older ST1 models did; this always had me worried that it would bend the door because the batteries weigh a lot (about 8 lbs in this case). Still, as clean and well-sealed as the neat side-door concept appears I found that the locking core on the right side was a little tight and the door popped out abruptly when unlocked (as shown in the video review above). It’s an area to take extra care with so you don’t drop a pack or tip the bike when struggling with the lock… use two hands!

Operating the Stromer ST1X feels clever because the power button is hidden under the top tube. This may deter thieves and confuse interested bystanders who become curious at the bike rack. Once pressed, the integrated LCD display panel comes to life showing your speed, assist level (1-3) and your battery capacity in a percentage based info-graphic. I LOVE that they show percentage here because it can be frustrating to only have five or ten bars that disappear in chunks. Duplicating some of these stats and adding a tuning mode is the smart phone app which runs on Android and iOS. With this app, you can edit and customize assist level 2 to perform however you want… zippier at start or optimized for efficiency etc. I love the visuals they chose which actually demonstrate how more power and zip will limit range. Any time you’re accelerating quicker off the line and riding above 20 mph you’re significantly tapping the battery but given the slightly lower torque rating of the ST1 X I’m guessing that it will get better range than the ST2 models with equivalent battery size. The other cool feature of the app is an ability to lock your bike, get feedback on tampering and report it stolen. The locking feature can also be activated using the touch display on the bike but you’ll need your phone to track and unlock later. What it does is use regenerative braking to immobilize the rear wheel then flash the lights if someone begins moving it. One downside to these theft deterrents is that they cease to work as the battery becomes depleted. Coming back to how the display relates to the bike, I want to call out that it’s beautiful looking but not removable… This poses a trade off in terms of durability. When parking, I think I’d consider tying a bandana around the top tube to cover the display quite honestly but then you don’t want it holding in water and messing up the screen if it rains either. Because of how low the touch screen is mounted you have to spend more time looking way down vs. just a bit down to the handle bars like many other ebikes. Sure, you could mount your phone to the bars and use it as your display but that will sap your phone’s battery and unlike the ST2 and ST2 S models, the X doesn’t have a USB charging port in the head tube which could keep it charged. Most of the time I use the control pad button ring which is mounted flush with the right grip and brake lever. It’s easy to reach, backlit, has a clicking response and also activates the lights. In this way, I don’t have to take my hands off the bars or look down in order to control how the bike responds.

While you don’t get the fancier lights, highest-end drivetrain or electronic shifting with the ST1X you do get the heart of the ST2 frame and battery systems. And as cool as the LED headlight thing is on the ST2, I actually know some people who dislike how it looks and use electrical tape to hide it and blend in more. The ST1 X weighs nearly 60 lbs which is on the higher end, even with the weaker motor, but it still gets you up to that ~27 mph top speeds (it was windy so I wasn’t consistently hitting 28 in the video). At $5k this is not an affordable electric bike but to me it’s obvious that it’s still better than the cheaper knockoffs and worth paying for. Stromer does one type of bike and they do it very well… If you want more comfort, they sell a customized SR Suntour Epixon suspension fork with matching fender and you can always add a suspension seat post (I’m told by some of the shops I visit that most people get one of these accessories when buying the ST1 and ST2 models). Whether you’re short, tall, like classic professional colors (black and white) or want something more sporty looking… they have you covered. It’s worth noting that the tires on the ST1X don’t have reflective sidewall stripes like the ST2 and this might be an argument for the white frame so cars see you easier from the sides. Also, the rear light does not go extra-bright when the brake levers are activated and the fork is Aluminum vs. Carbon fiber which feels stiffer and weighs more. On the surface, this bike is an ST2 but after careful study, the differences make their way out. If you’re buying a bike like this to replace your car (or if you never had a car) it’s wonderful to have shop support and a company that has been selling ebikes in the US longer than many of the other major brands. If you know it’s going to get banged up at the rack and you don’t need the extra torque or fancy lights and USB then this cheaper model could be the way to go. In any case I’d use good locks and consider bicycle insurance. Stromer is a European company but one that has invested heavily in the US and their products seem to hold up well over time. The ST1 X is set to go on sale in the United States in March 2017. Big thanks to Stromer for partnering with me for this review.

Pros:

• Solid, durable frame with internally routed cables and a beautifully integrated (and hidden) battery… it’s a stealthy electric bike, especially if you go for black
• Available in three frame sizes and two frame styles so you get a comfortable fit, I especially like the mid-step frame for people with shorter legs
• The tubular fenders are very sturdy and well supported on the sides by struts, they don’t rattle even at higher speeds and hug the tires close which keeps them out of the way
• While the rack doesn’t support as much weight as some others, it’s slim and aerodynamic so it stays out of the way when not in use, I like that it supports the rear fender and has an integrated light
• Even though the ST1 X doesn’t have the fancy LED running light or USB port at the front and the headlight is a plastic Roxim brand vs. the superior Aluminum Supernova… it still works well and runs off the main battery (just like the backlight) which is great
• Both wheels attach with thru-axles for improved strength and stiffness in handling, that’s a nice upgrade considering the weight of the frame and higher top speeds
• Decent Tektro hydraulic disc brakes with large 180 mm rotors front and rear, I like that both brake levers have motor inhibitors that activate regenerative braking
• Integrated wireless technology lets the bike receive software updates on the fly so you don’t have to go into a bike shop and wait or pay extra to get the latest versions
• Uses a TMM4 torque sensor in combination with a gyroscopic accelerometer to provide fluid acceleration, it’s more consistent than just a TMM4 as I’ve tested with some other models
• The ST2 battery design is used here and seems to slide into the downtube easier (relying on the frame for support vs. the door), the shell of the battery pack is made with colored Aluminum which looks cool and you can charge it on or off the bike using the same EnergyBus magnetic plug… Older ST1 models relied on a dongle adapter which was easier to lose and more prone to bending pins or tipping the bike over if tripped on vs. the magnetic one here that just pops out
• If you want to go further, Stromer offers two upgraded battery pack options for 814 Watt hours or 983 Watt hours… the ST2 and ST2 S feature these packs standard but cost a lot more
• Stromer is an established brand dating back to 2009 with global distribution, the ST2 models (which the ST1 X is largely based on) received a Eurobike Gold award, Red Dot Quality Seal award, two Testsieger awards, an Outside magazine award, a Taipei Cycle show award and an iF design award
• Every battery that is shipped with a Stromer electric bike, including the ST2, is charged with solar power (which also powers the myStromer AG headquarters in Oberwangen, near Bern / Switzerland)
• I love that the bike has a kickstand and that it’s not the auto-sprung design that many speed pedelecs have! This one stays up or down as you set it and isn’t as prone to letting the bike tip if bumped
• The chainring sprocket uses a narrow to wide tooth configuration that creates a tighter fit with the chain, reducing slippage and drops… I like that the downtube is tapered in near the bottom bracket to allow the chainring to be closer and that there’s a sturdy bash guard on the outside of the ring to protect your pants when pedaling

Cons:

• Most of the Stromer electric bikes I’ve tested feel stiff and jarring because they don’t come stock with suspension, that’s especially true with the ST1 X because the fork is Aluminum vs. Carbon fiber… but at least it’s tough and they offer a replacement SR Suntour suspension fork if you want, consider adding a 31.6 mm seatpost suspension from BodyFloat
• The flip side of regenerative braking is cogging drag that affects the bike whenever you’re costing unpowered, Gearless hub motors are quiet but don’t always freewheel
• As fancy as the touch screen display is, you can’t remove it when parking which may result in wear or damage, it’s also located lower on the frame so you have to look down more than handlebar displays which could be distracting for some… you can use your phone as a display and mount it on the handlebars but without the USB charging port on the ST1 X vs. the ST2 you might wear your battery down if you leave it on for long rides
• In some ways I like the torque sensor but it definitely requires more effort than cadence sensors and some multi-sensors, it seems to favor slower pedaling with more force and I prefer to spin fast so it’s a mixed feeling for me
• There’s a little plastic shield covering the charging port on the left side of the downtube and it’s easy to break off… then your charging port will get dirty :/
• Rather than using the same Syno drive motor that the ST2 models have, Stromer has opted for a slightly lower torque Cyro drive, it’s still large and heavy but just not quite as zippy
• Some of the cables stick out going from the handle bar to the top of the downtube… they are internally routed which is great but the wide bend sort of bumped into my knee when pedaling standing up at times, perhaps they could route them differently?
• It’s great that the bike has a rack and bottle cage bosses on the downtube but I really feel like they could have added a second pair on the seat tube for the high-step diamond frame and that would have been useful
• While the kickstand is nice to have, I wish it was rear-mounted instead of placed near the bottom bracket because it’s easier to collide with the crank arms there
• They key fits well into the lock but I found it tight to unlock, maybe that’s just because this was a brand new bike but it took both Chris and I extra time and effort to lock and unlock

Resources:

• Official Site: https://www.stromerbike.com/en/us/e-bikes/st1-x
• More Pictures: https://goo.gl/photos/rc8xny2cFB3StAGg8