ST5

1 review for ST5

1. 

   CC E-Cycles – April 24, 2023

   Video Review

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   Written Review

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   Stromer introduced it’s ST5 electric bike in April, 2018 and I was invited to a launch event at a shop called Best Electric Bikes USA. At the event, I spoke with several team members, including the CEO and VP of Worldwide Sales. The video review captures some of our conversation and is a bit longer than many others, in part because of the advanced design features, mobile app, and ride interviews I filmed at the event. What you get from the ST5 for $10k is an electric bike that is setup almost like a motorcycle or moped in terms of durability and quality. It’s designed to be a car replacement platform and can travel up to 115 miles on a single charge (more likely 60+ miles if you’re riding in the higher levels of assist). It accelerates extremely quickly and is more than capable of reaching the ~28 mph top speed of other Class 3 “speed pedelec” products. In fact, I was able to reach 29.5 mph and many in attendance expressed that they reached 31 mph (49.8 km/h). Weighing in at 66.5 lbs, the bike is definitely heavier than an average electric bike… by nearly 10 lbs. Custom-made tubular alloy fenders, thicker Pirelli Cycl-e tires, and a battery with nearly twice the capacity of what I’d call “normal” for the 2018 model year, is part of what causes this weight difference. This weight can be reduced by simply removing the 9.8 lb battery pack, and I’d suggest doing so before mounting the bike to an automobile rack or trying to lift it for service. The weight doesn’t impact acceleration and actually improves ride quality, in my experience, because the frame doesn’t vibrate as much. The frame is available in three sizes, to improve fit, and is made from aluminum alloy, along with the fork. You can improve comfort by reducing tire pressure, adding a 31.6 mm seat post suspension, and replacing the rigid fork with the upcoming inverted air suspension from WREN. I was told that this part, along with a rear rack platform, will be available mid-year, but was not given details about pricing. There’s only one color choice, and neither the frame nor tires seem to have any reflective accents. I asked the Stromer team about this and was told that European guidelines have dictated that reflective tires not be used for Class 3 products… which is too bad. One more positive change however, is that the kickstand has also been updated to reflect changing laws, and no longer auto-springs up. It’s just a traditional stand now, with a physical push to stow. The final European guidelines for this ebike include an extra-bright headlight, rear light with bright activation with either brake lever is pulled, and brake levers with ball-ends to reduce the risk of impaling riders in the event of a crash or letting their hands slip off. Hooray for rules! If anyone out there has feedback about the reflective tire guidelines, and why they aren’t allowed for Class 3 in Europe now, please reply below in the comments. I do wish that Stromer would have worked with Pirelli to make a North-America specific tire that was reflective, but you could probably swap the stock tires for something like this down the line, on your own. Before digging in too much further, I want to point out that Stromer offers several complementary e-bike models that are specced down and priced for less. The ST1 X, for example, is priced around $5k and could be a great option for those who are alright skipping the Bluetooth keyless activation, more powerful motor, electronic shifting, larger battery, and fancier brakes on the ST5. This product is the top of the line entry for a company that is already known for producing premium high-priced bikes. Part of what you get for the money is a dealer-exclusive experience with industry-leading two-year warranty and products that are produced using sustainable energy in Switzerland. Neat 🙂

   Driving this bike is Stromer’s most powerful gearless hub motor to date, the SYNO Sport (manufactured by TDCM, Ultra Motor). Being gearless, this motor is near-silent and super durable. There aren’t any reduction gears inside rubbing on each other, so in order to get power, the hub itself is thicker and wider. A series of rare-Earth magnets line the outer wall of the casing and electromagnetic staters branch out from the middle. In addition to reduced noise, this motor also offers regenerative braking and five levels of recoup. It’s a fancy system that reduces wear on brake pads, and can simulate hill climbs or refill your battery on long descents. Why aren’t all motors setup like this, you might wonder? Well, the motor itself is much hevier at roughly 10.58 lbs vs. 7 lbs for an equivalent planetary geared design. There’s also a bit of cogging drag vs. complete freewheeling. The drag does put a small bit of energy back into the battery pack, but many would argue that this natural recoup, and even regenerative braking, is offset by the added weight of the motor. For a heavier bike like the ST5, and many hybrid and electric automobiles, the efficiency and gain from regenerative braking is better. This system is definitely more complex, and more expensive, but Stromer updated their plug design to something called HIRT for 2018. This means that rear-wheel service should be easier and the single cable design presents less clutter than some of their older models. Hub motors provide several benefits that I want to explore quickly, as we see more and more quality mid-drive options on the market today. The motor is completely separate from the pedal drivetrain and won’t interfere with shifting or cause premature wear on your chain, sprockets, and derailleur. It accelerates at a constant, regardless of which gear you’re pedaling in. And, it’s generally quieter and smoother feeling. You won’t get the same efficiency as a mid-drive unit, assuming you were shifting gears thoughtfully, but you also don’t have to shift gears as actively to reach different speeds. For any hardtail electric bike, where unsprung weight is not a concern, hub motors are still a great option. I especially enjoyed the new SYNO Sport, which was noticeably quicker and more powerful than almost all of the other hub motors I have ever tried (having tested over 800 ebikes). Finally, because of how the battery is positioned in the frame, the bike is not especially rear-heavy, in spite of the larger hub motor positioned in the back wheel.

   Motors aside, this electric bicycle has a fantastic human-powered drivetrain. The 11-speed Shimano XTR derailleur shifts electronically with Di2 and positions the chain consistently, every time. You won’t suffer from cable stretch and be required to perform tuneups as quickly or as frequently, because the actual cable is much shorter. Pressing the button-style trigger shifters near the left grip requires less physical force, and offers multi-step shifts if you press and hold. This feature was a big delighter for people who had never tried it before, during the launch event. It’s more of a “nice to have” feature in my view, but it definitely changes and improves the experience. One thing that is missing from this e-bike is a readout for which gear is in use. Most other Di2 electronically shifted electric bikes use the Shimano display panel, which doubles as an ebike menu. You can see what I’m talking about on the BULLS E-CORE Di2 FS 27.5+ here, scroll over to the 5th picture. Stromer has gone their own direction with a proprietary top-tube integrated touchscreen LCD unit, instead. It does not show which gear you’re pedaling with, and to be honest, I don’t really miss the information. with such a wide spread, 11 to 42 teeth, this thing is setup almost like a mountain bike for climbing and yet, still feels comfortable at the ~30 mph mark. I found myself sticking with the middle gears and rarely using the lowest two gears, because of how powerful the motor is when starting. It offers up to 48 Newton meters of torque, and that number is not embellished or exaggerated like a lot of other hub motor powered products that say 50 Nm or 60 Nm… but unfortunately, I cannot verify the stats in those cases. With Stromer, you really can feel the power and are getting 700 or 850 watts (and probably more than that at peak). I was a little confused by the communications from different people at the company, who said that they had to measure and report power differently in different geographies (Europe vs. the US). Whatever the number, I can tell you that this bike is powerful and very, very fast. As a final quick tip, you can fine-tune shifting with the Di2 system by holding the little button on the black port at the lower backside of the seat tube for a few seconds. Once it flashes, you can use the trigger shifters to do micro-adjustments and align the derailleur perfectly. This port is also where you charge the Di2 system, which is not connected to the main ebike battery.

   Powering this electric bike is a beautifully packaged, extremely high-capacity Lithium-ion battery that is filled at the Stromer headquarters with wind energy. It offers 48 volts and 20.5 amp hours for a total of 983 watt hours (nearly 1 kilowatt hour of capacity). Despite the large size, this battery is fairly easy to deal with, because there’s a swiveling plastic handle built into the top cap. Be very careful not to drop the pack, and store it away from extreme heat or cold to maximize its life. The bike comes with a rather large and bulky 2.7 pound charger that puts out 4.5 amps for faster charging. In my opinion, it doesn’t look as beautiful as the Bosch solution (which puts out 4 amps and weighs just 1.6 lbs) and it is definitely heavier and larger… but it does offer a magnetic charging tip that won’t get bent or pull the bike over if tripped over. This same tip is used to plug into the port at the top left side of the downtube as well as the base of the battery pack itself and is a big improvement over the dongle adapter used for the ST1 models of years past. That dongle adapter was easily lost and had to be plugged in more firmly. In addition to the stock charger, Stromer also offers a compact travel charger with one very neat performance feature; it can maintain the pack over long time periods. Usually, it’s best practice not to leave a large Lithium-ion battery plugged into a charger for days, weeks, or months on end. The battery can overheat and get damaged if the battery management system and charger are not configured properly. With the compact option from Stromer, it sounds like you’re actually encouraged to leave the pack plugged in and this will allow it to automatically top off and avoid the slow discharge and eventual damage of reaching zero (which damages the Lithium-ion chemistry of the cells). I’m not sure how much a replacement battery costs, but my guess is somewhere in the $1,500 range. So, in summary… the battery looks great, fits beautifully into the downtube – nearly hidden, keeping weight low and center, is safe to carry, has a great charger, and should be kept between 20% and 80% at neutral temperatures for best results. It really will offer incredible range, even in the second and third levels of assist, because the bike is so efficient and the tires are so smooth and firm. I personally choose to ride at a lower pressure, around 25 PSI, in favor of comfort… and still expect 60+ miles per ride.

   When it comes to actually powering the bike ion, I love how simple Stromer has made their interface. There’s a rubberized button positioned directly below the OMNI LCD screen on the top tube. One press will initiate the display and subsequent presses will switch from ride menus to a settings menu (where you can eject the battery pack). The screen itself is now color and uses a force sensitive touch system that works with generic fabric gloves. The default view shows your current speed, battery level (with a very precise infographic vs. a basic five or ten bar view), a range estimate that dynamically updates as you press the plus and minus keys on the button pad (near the left grip), and your current assist level. There are four levels of assist now, ranging from 1-3 and then up to S (which may stand for sport or speed?) If you press the OMNI display unit, it will cycle to two separate views. The first shows a clock and trip average speed the second shows trip distance and trip time. One of the biggest compromises that I noticed with this display is that it takes a bit longer to boot up. And, in my experience, it’s best not to pedal during the boot-up process because the system is measuring torque and calibrating a zero point. Stromer uses the TMM4 torque sensor at the rear dropout along with some gyroscopic measurements. I noticed that, whenever I started pedaling, the motor would kick on smooth and strong… but would then fade out slowly when I stopped pedaling (unless I pulled the brake levers, activating regen). It’s a smooth stable (safe) feeling that is preferable to other high-powered electric bikes that can go from accelerating to almost shifting you forward when the motor cuts off, even when you aren’t braking. The OMNI display has a light sensor built in that shifts the display from white background to black (at night and low-light situations) and you can also manually set this by going into the settings section of the menu (press the rubber button below the top tube then click settings on the display). I was told that the older ST2 models can be updated to use this same color LCD, but it costs $1,000 to install.

   There is so much to say about the display systems and app for this ebike, it starts out very simple, but you can really dig in with the iOS and Android smartphone application to adjust the acceleration and speed settings of the second level of assist (the first, third, and S remain unchangeable). There’s a GPS navigation scree, profile information, and even a way to report your bike as stolen and track it using GPS. I was told that there’s a cell phone chip installed on these bikes and that Stromer pays for the service to track the bikes and aid in recovery. When the bike is locked, you can set it up to respond to your smartphone based on proximity and unlock, or you can use a manual-press pin number. If a would-be thief tries to walk or ride off with your bike, it alerts you and the motor locks up using the highest level of regeneration. I tried to pedal a locked bike and came away convinced that it would be unrideable. Apparently the lights even flash! Another cool feature that Stromer has added to their ST5 is an electronic horn, built into the downtube near the bottom bracket. The button to honk this horn is placed within reach of the left grip, alongside the headlight bright button and + and – keys for assist navigation. It’s very satisfying to hop on this bike, power it up, then pedal along without looking down at a shifter or LCD screen. It’s intuitive and powerful enough that you don’t have to overthink anything or feel distracted by the display. Even if you’ve forgotten to downshift, the motor is powerful enough to get you up to speed quickly and climb steeper inclines without much pedal support. You do have to push in order to activate the TMM4 torque sensor, but the gyroscope and accelerometer make it a much more consistent and predictable experience than many other ebikes that only have the TMM4 and use less advanced control systems. For those who are excited about the smartphone app, and want it in view, Stromer has a hidden mount just below a cap on the custom stem. You can position your phone there and plug in to the full sized USB port on the front of the steering tube. It’s a clever and beautiful design that is within reach so cables won’t be strewn about the bike. Just grab a short black Lightening (for iPhone), USB-C or Micro-USB (for Android) cable and you’re all set.

   Not everyone can or would choose to pay $10,000 for an electric bike, but this product does deliver an integrated experience, level of control and safety, and high performance that none other can match. Yes, you could build an electric bike with similar top speed, but it wouldn’t look this beautiful, have the GPS app features, or ride as quietly and smoothly… it probably would not have regeneration, and things like 203 mm hydraulic disc brakes with custom red quad-piston calipers like a fancy Porsche or Tesla. Yes, this is the supercar of electric bikes, and I am SO grateful that they will be releasing a rack upgrade and suspension fork, because those were my two biggest gripes upon first seeing the ST5. I love comfort and prefer a more upright body position. So, it’s great to know that the ST5 frame was designed to be more upright and comfortable than the older ST2 platform. Your body may not be quite as aerodynamic, but that’s okay, given the larger battery and efficient recapture modes. Unfortunately, you cannot swap the stem out, nor can you change the handlebars (which is something I did for fun on an ST1 Limited a couple years back, for my father). One final consideration for me would be adding black reflective stickers to the side of the frame and rims to stand out more. I want to recognize how Stromer uses a plastic leash to keep the magnetic charge port cover from getting lost (unlike many competitors) and that they opted for a narrow-wide chainring to keep the chain from bouncing off while still including an alloy outer guard to keep your pant legs clean and protect from high-center strikes. Is there room for improvement? Yes, definitely. The kickstand is positioned mid-frame which can cause pedal-lock when backing the bike up if not stowed, the unique Torx bolts on the front and rear axles are not commonly used (at least in America) so it would be nice if this bike came with the tool needed to service flats and do maintenance (it’s not expensive to buy a set online yourself, however), and it would be nice to have the suspension fork option ready at launch vs. 6+ months out. Big thanks to Jakob, Tomi, Matt, Brandon, and the team at Best Electric Bikes USA in Denver for their time at the launch event. Thanks to Stromer for partnering with me on this review and to those who went on camera to share their ride expeirences. Please share your own experiences, feedback and corrections for this article, and questions below in the comments or the Stromer Ebike Forums.

   Pros:

   • This is definitely the most powerful and fastest Stromer electric bike to date, I was able to reach 29.5 mph pretty easily and that provides a sense of confidence and control when riding near automobiles, the frame and tires are solid
   • Despite the higher speed and lack of suspension, the bike feels pretty comfortable because the heavier all-alloy frame doesn’t vibrate and the larger 27.5″ x 2.4″ tires cushion cracks and bumps, especially if you lower the PSI to ~27.5 (I took them down to 25 PSI since I weigh a bit less at ~135 lbs)
   • Hardly any wires are exposed, the bike is super stealthy looking and the motor is extremely quiet, I got the feeling that shops can still access wires easily enough for tuneups however, because of the stem cover design and open downtube (when the battery is removed) exposes them
   • The default battery charger is a bit large and heavy at ~2.7 pounds, but it uses a magnetic connector that won’t tip the bike or get bent and broken as easily and it offers 4.5 amp output vs. 2 amps on most competing chargers, and that makes the battery fill faster which is great when you’re working with a battery that is nearly double the size of normal
   • The battery pack can be charged while mounted inside the frame or stored separately and there’s no dongle required, Stromer also sells a compact charger with smart maintaining feature that will keep the cells from discharging slowly over time if you aren’t riding for months on end (which can damage them)
   • Extra-large tubular alloy fenders feel sturdy, don’t rattle around when riding on bumpy terrain, and are solid enough to support a rear rack (sold separately), but Stromer also included bottle cage bosses on the downtube for bringing fluids or a folding lock, I think the could have added a second set on the seat tube as well, but you could always use an SKS Anywhare adapter for that if you need the space
   • The updated OMNI display panel displays in color and the top level of assist “S” is bright red, so you can tell what mode is selected without having to focus on the small numbers, Also, I love that the display has a touch display that is force sensitive because it seems to work with normal gloves
   • Excellent drivetrain, you get more than enough gears for climbing with a 66.5 lb bike (if the battery does run out) and keeping a steady cadence at ~30 mph, the electronic shifting is crisp and accurate, and the derailleur has a one-way clutch to keep the chain tight on bumpy fast rides (just click the little orange lever into the up position)
   • I really appreciate the Ergon saddle and locking grips, they feel good to me and I wouldn’t replace them like with a lot of cheaper ebikes, the TranzX Antishock seat post also performed well, but I might upgrade that to a 31.6 mm Kinekt suspension post
   • I like how the LED running light in the front has a USB port built-in so you can maintain your phone while riding, this is especially relevant given the Stromer app which uses Bluetooth and can show directions and routes
   • The locking features are pretty cool, you can set the app to lock and unlock the bike based purely on your phone’s proximity… or unlock it remotely for a friend, the bike has a smartphone chip onboard that syncs with GPS for theft tracking and recovery, I was told by a shop tech that registering Stromer products is very easy compared to many other brands, which is nice
   • The chainring uses narrow-wide teeth to keep the chain on track (vs. using a full guide), the alloy guard on the outside of the chainring will protect your pant legs and it also protects the teeth if you collide with a high curb or other obstacle
   • It’s a minor pro, but I really appreciate the large alloy pedals that they specced for the ST5, they provide good traction and a larger surface area than the older alloy cage pedals used on other Stromer ST1 models
   • The electronic horn worked very well and commanded more respect and feedback from fellow cyclists and cars than a tiny bell, for such a powerful and capable electric bike, it’s nice to have that sort of signal built in
   • Every battery that is shipped with a Stromer electric bike, including the ST5, is charged with solar power (which also powers the myStromer AG headquarters in Oberwangen, near Bern / Switzerland)
   • Pedal assist feels very responsive because it relies on signals from a TMM4 torque sensor in combination with a gyroscopic accelerometer, the power ramps up quickly and fades out slowly as you stop pedaling… or you can pull a brake lever to cut it more instantly and activate regen
   • The display panel features a day-night sensor for back lighting and is integrated directly into the top tube which reduces clutter on the handle bars, there are lots of settings to adjust here including dark or light color schemes
   • The custom 15 LED running light (at the head tube) looks cool but the Supernova M99 Pro is the true tool for visibility with two modes (LED vertical lights along the sides or a super-bright main light offering 1250 Lumens), the 5 LED tail light (also by Supernova) works as a running-light in low and when you pull either brake lever it goes high, lights can be shut off using the mobile app
   • Custom designed battery pack slides into the downtube much easier than on the ST1 models (it doesn’t fit onto a track, just into the box area of the downtube)
   • The battery offers high-capacity 983 watt hours and is cross compatible with the ST2 S and ST2 (which had a smaller pack by default), that’s great if you’ve already got a Stromer sitting in your garage and want to swap between bikes or go for a long trekking ride with two batteries
   • Any time you brake with either lever (not just the right one like with ST1 models) power regeneration kicks in and the bike “recoups” some energy, you can also hold the minus button and select from five recoup levels for longer hills to get more energy
   • Premium hydraulic brakes with carbon steel rotors dissipate heat and provide ample stopping power through quad-piston calipers and extra-large 203 mm rotors
   • Stromer is an established brand dating back to 2009 with global distribution, the ST2 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 and the ST5 shares many design features and just builds on that platform with a stronger motor and more integrated systems
   • The smart phone app interfaces with a cloud platform called OMNI that lets you interact with the bike remotely including an anti-theft measure that will lock the motor, flash the lights and notify you via text, the system will also help you track the bike down using built-in GPS
   • The bike itself has built in wireless technology allowing it receive software updates on the fly… this means you don’t have to go into a bike shop and wait or pay extra to get the latest and greatest

   Cons:

   • I’m really glad that Stromer has been able to drop the spring loaded auto-stow kickstands that they used to spec, because they made it easy for bikes to tip over accidentally (apparently the European regulations changed and allowed for this), but the existing stand is still mid-mounted and can block the left pedal when backing the bike up, creating pedal lock
   • This ebike is heavy, the heaviest Stromer to date, actually… weighing in at roughly 66.5 lbs (30.16 kg) it’s nearly eight pounds heavier than the ST2 S I reviewed a year prior, perhaps it’s the larger tire diameter and thickness combined with the custom handlebar and stem setup, at least the bike feels very sturdy
   • Most of the Stromer electric bikes have been priced at the high-end, and the ST5 is ~$10k which puts it at the very top, for the money… you do get three frame sizes, two years of full warranty support, and one of the fastest and most powerful urban electric bikes around, but it’s still a lot to spend, consider getting bicycle insurance to protect the bike and any accessories you add
   • Unless you’re using a phone app, the display is positioned pretty far down and back, which means you’ll have to take your eyes off the road to read how fast you’re going or approximate range… I recommend pulling over to read and interact with the display here, or just clicking the left button pad and guessing what level of assist is active vs. glancing down because the screen is a bit small and so far down
   • If you want to add a suspension fork and still have the front fender and custom stem work… you may have to purchase directly from Stromer (which is partnering with WREN to offer an inverted air fork in mid-2018)
   • The ST5 is said to have a more upright geometry than some of the older ST2, ST1 X and ST1 models, but you can’t really do much to shorten or raise the stem or swap-in mid-rise or backsweep handlebars because it’s all so proprietary
   • I was disappointed to see that the tires do not have reflective stripes, but I asked the Stromer team and they said that this is a European requirement (not to have the reflective paint) because the bike is Class 3 and treated more like a moped, perhaps the reflectivity was just too much? I’d probably use black reflective stickers all over the sides of the frame to help it stand out at night because the headlight and backlight do not shine out from the sides very much
   • I was told by Stromer that the bolts which secure the wheels require a T70 star driver… which is very rare, someone at the shop told me it was a T60 and I couldn’t confirm, this would be a good accessory to pick up when you get the bike (probably online because it is rare), so you can change flats and do basic maintenance, here’s a kit with both sizes for $16 on Amazon and I welcome your comments below to confirm the correct sizing
   • 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 circumference 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 ST5), a benefit that negates this con somewhat is the active regeneration and regenerative braking
   • The Di2 electronic shifting unit and derailleur run on independent batteries, there’s a charging port on the bottom backside portion of the seat tube and this is also where you can activate derailleur adjustment (by holding the button for a few seconds until it flashes and then using the trigger shifters to calibrate and offset any cable stretch that may have occurred over miles of riding), frankly, it would be nice if the Di2 electronic shifting was just wired into the bike’s main battery vs. using a separate one
   • While the bike is available in three sizes, you only get one color scheme (gray with red accents) and a traditional high-step frame style vs. the standard ST2 which comes in a step-thru frame that some may find easier to mount
   • The ST5 models that we looked at didn’t have neoprene wraps on the chainstays to protect from chain slap, perhaps the final builds will have these… but you can always use clear plastic packing tape or get an aftermarket sticker like this
   • It seems like the display panel takes a while to boot up, it’s not instant (or nearly as fast as Bosch or Yamaha systems) and I think it’s best not to mount and pedal the bike while it is turning on because the TMM4 torque sensor has to calibrate