2015 Stromer ST2 Review


Technical Specs & Ratings


2015, 2016, 2017



Class 3




Hydraulic Disc



814 Wh

814 Wh

58.5 lbs / 26.56 kgs


Threadless Tapered 1-1/8" x 1-1/2"

Custom Alloy, Internal Cable Routing


Ergon GS1 with Lockers

Aluminum Alloy


Ergon SM3, Special Edition

Aluminum Alloy Platform

Hydraulic Disc

Magura MT2 Hydraulic Disc Brakes with 180 mm MT4 Carbon Steel Rotors

Ebike Systems

Class 3


SYNO Drive (Ultra Motor)


Integrated, Backlit, Touch Screen LCD

Omni Cloud Mobile App (View and Enter Service Records, Update Firmware, System Status, Location Tracking, Motor Block, Lock and Unlock, Performance Tuning)

Omni Cloud Mobile App (View and Enter Service Records, Update Firmware, System Status, Location Tracking, Motor Block, Lock and Unlock, Performance Tuning)

814 Wh

814 Wh

Samsung 48 Volt, Lithium-ion, 17 Amp Hrs, 10.03 lbs

More Details

Video Reviews

Written Reviews

The ST2 is a third generation electric bike from the Swiss brand Stromer that has been around since 2009; the bike is distributed globally. It maintains the quality, style and speed performance of the older ST1 Platinum but adds bluetooth connectivity for an app which allows riders to “tune” settings and activate anti-theft features including GPS location with a tracking range in the hundreds and possibly thousands of miles (wherever the GSM network gets service). It’s got built in GSM hardware that can communicate with a cloud network for automatic updates, a touch screen LCD interface and beautiful LED lights front and rear in addition to an included City Kit with aluminum alloy fenders and carry rack. All of this along with an enlarged battery pack for increased power and range but the ST2 weighs about the same as the older ST1 at ~62 pounds depending on the frame style and size. It’s pretty amazing and it costs $6,990… so it had better be :)

Driving the ST2 is a 500 watt gearless rear hub motor setup in a direct-drive configuration. It offers 42 newton meters of torque and has a peak output of 800 watts which is very noticeable when riding. It’s quiet but but very responsive and powerful. Adding to this sense of power is a TMM4 torque sensor (a metal plate that senses strain built into the right rear dropout) and an accelerometer and gyro in the LCD display unit which helps the computer assess terrain steepness. This is truly one of the most impressive feeling ebikes I’ve ridden and with three levels of assist you can choose to optimize for distance (up to 90 miles) or speed (up to 28 miles per hour).

Powering the drive system and LED lights is a purpose built Lithium-ion battery pack that can be charged on or off the bike. It weighs a bit more than last-gen batteries from Stromer (about four pounds more) but you get a massive 48 volts of power and 17 amp hours of capacity. I love that even though the battery mounts inside the downtube on this bike, they still included water bottle cage braze ons. I love that the motor and battery on this bike work together to allow regenerative braking to “recoup” energy as you apply the brakes and during the video review I mentioned that the brake cut-off to the motor seemed a bit delayed. This may have been due to regen activating. Keep in mind that if your battery is completely full, regen won’t work (this protects the battery from overcharging).

There’s a lot to say about the new backlit display panel that’s built right into the top tube, just behind the head tube. It’s very beautiful and sleek but not as easy to read as a handlebar mounted display. I’m near sighted for one thing and having to look even further down (both vertically and horizontally back towards my crotch vs. the handlebars) isn’t perfect. Still, I didn’t use the display as much as the button pad that’s nicely situated near the right grip. This has an on, up and down button which are rubberized and backlit. I like this approach vs. the little joystick on the Specialized Turbo which seems more delicate but I prefer the display on the Turbo to the fancy touch screen here. On the ST2 the touch screen can cycle through readouts and adjust settings. All in all, this system definitely gets the job done and I do like that they’ve included front and rear lights in addition to a female USB port in the head tube for charging your smart phone or other electronic device (which you could use for GPS navigation, music etc.).

All things considered, this is one of the most beautiful, enjoyable and well thought out electric bikes I’ve ever seen. It’s completely purpose built and the addition of thru axels for increased strength, hydraulic disc brakes for improved stopping power and new bottom bracket hardware to reduce the gap where the cranks insert (keeping out dust and debris) set this ebike apart. Indeed, it is expensive, but still comparable to the Haibike Superrace and Specialized Turbo S which offer speed pedelec performance and custom frames. I love that the ST2 has a smart phone app that puts you in control of security and opens the system up for performance tuning. With this bike you can get a size and style that fits, enjoy quality accessories that all run off the same power system and benefit from future improvements to software all downloaded for free directly to your bike.

This is the kind of innovation I’ve heard about and seen on Kickstarter and design labs at Universities across the world and while I’m excited to see it in person, I can’t wait to see Stromer add even more features down the road such as radar powered car proximity alerts with haptic feedback in the handlebars, heart rate driven motor output, continuously variable transmissions and belt drives for shifting at standstill and quieter operation. Perhaps we’ll see Google Glass integration for crash impact alerts and data syncing with a rear safety camera in addition to the LED lights (something like Fly6). The ST2 is the closest thing I’ve seen to this type of technology reaching mass markets and it’s very exciting.


  • 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)
  • Two frame styles (high step and step-thru) with multiple frame sizes and two colors (gloss white and matte black)
  • Extremely high end components including Shimano Deore XT derailleur, front and rear thru-axels and Schwalbe Big Ben tires
  • Speed pedalec capable of reaching 28 miles per hour, very responsive (uses TMM4 torque sensor in combination with accelerometer and gyro)
  • Backlit LCD display built right into the top tube with touch screen interface to switch between three views and edit settings
  • Great utility from included full length aluminum alloy fenders and rear carry rack
  • Matching Stromer branded Ergon saddle and GP1 handle bar grips with end lockers
  • Backlit button pad on right handle bar is easy to see, reach and navigate when riding, less fragile than the Specialized Turbo’s “joystick”
  • Sleek integrated LED tail light and headlight with built in USB charger port and daytime running lights, iconic look
  • Removable battery pack for safe storage, charging and reduced overall weight during transport
  • Enormous and powerful 48 volt 17 amp hour battery pack uses light weight Lithium-ion cells that are durable for increased charge cycles
  • Regeneration feature built in to activate as brake levers are pulled, quality 180mm disc brake rotors are designed to dissipate heat more quickly and work with Magura hydraulic levers
  • Thru-axel provides increased rigidity, overall toughness and ease of wheel removal/replacement (lining up disc brakes)
  • Third generation build from Stromer, an established brand with global distribution (recipient of Eurobike Gold award and Red Dot Quality Seal award)
  • Syncs with smart phones using Bluetooth (myStromer App for customizable motor output, remote configuration, charge status, service booklet and anti-theft mode), auto updates with GSM (for software improvements/fixes) and GPS for recovery due to theft or loss (in anti-theft mode the motor locks up and lights turn on)
  • LCD display panel is mounted further down so it can be harder to read due to distance and it also requires you to crane your neck a bit more as well


  • Although the brake levers do include a wired cutoff switch to cut power to the motor I found that it did not feel as instantaneous as some other models (this may be due in part to regen mode activation)
  • This is one of the heavier city style electric bikes I’ve tested in the high-end category at ~62 pounds
  • Dealerships that offer Stromer electric bikes are growing but the service network is smaller than a brand like Specialized, Haibike or IZIP
  • Cogging slows down the rear wheel when motor is not in use vs. a freewheel (metal staters repel the strong rare earth magnets located around the circumfrance of the hub casing – this is a con for all direct drive gearless motors but more noticeable on high power motors such as the one used for the ST2)

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