The ST5 is available in three frame sizes: a Medium made for those under 5’10, a Large fitting riders between 5’9” and 6’2”, and an XL for riders above 6’1”. Prospective buyers should expect a recommendation from their dealer when shopping, but we expect the broad fit range to resemble 5’5” to 6’6” across all three sizes. At 5’11”, I found our Large test bike to be well-suited to my build, though it’s worth pointing out that, had I needed some adjustment, the bike’s custom monocoque (single piece) stem and handlebar might have been a limiting factor.
As I anticipated, the bike excelled in terms of comfort. Its riding position, while fairly sporty and forward-leaning, felt accommodating and enjoyable. The Ergon SMC 40 saddle was slim but supportive and comfortable. I was thrown off slightly by the relatively slick top surface of the grips, but their textured underside was comfortably squishy and easy to hold on to.
The base model of the ST5 does not include a suspension, though our test bike included an appreciated, optional Kinekt active suspension seatpost with 65mm of travel. An optional Wren Sports suspension fork with 30mm of travel is also available, but I found myself not missing it, as the bike’s overall ride comfort was enhanced greatly by the wide tires; by reducing the tire pressure slightly, the tires became a cushion that absorbed bumps and vibrations.
In terms of handling, the bike’s size and weight were noticeable; it felt better suited to riding straight and at speed than at weaving through traffic. It responded well when cornering, though its agility was somewhat limited.
E-bikes with rear-hub motors usually give the sense of being pushed from behind, but this seemed less prominent on the ST5; its propulsion felt more natural. Obviously, it is not a mid-drive, but it felt closer than most rear-hubs I have tested. In addition to the motor being essentially silent, its output through the PAS felt smooth and adaptive.
Many of the ST5’s premium features contributed greatly to its ride quality. All of the following elements were spectacular additions to the bike’s functionality:
In addition to offering snappy, responsive shifting when moving, stopped, or pedaling uphill, the Pinion gearbox greatly reduces maintenance needs and wear. Since the system is completely sealed, the only maintenance needed is a change of the internal oil bath either yearly or after 6,200 miles (whichever passes first). With the included Smart.Shift module, the system downshifts automatically to the starting gear of your choice when coming to a complete stop. Users can also customize the behavior of the electronic shift levers.
The Gates carbon belt is another extremely low-maintenance component; it is recommended that riders clean any dust, dirt, or mud regularly, but the belt is rated to last twice as long as a chain. An included automatic tension wheel maintains the correct amount of resistance should the belt stretch. Combined with the Pinion gearbox and the rear-hub motor, this drive system is incredibly easy to use and worry-free.
The ST5 Pinion also includes an advanced onboard security system to deter theft. It uses an internal SIM card for location tracking (and navigation, but we’ll get to that) that uses the Swisscom network in Europe, and the strongest local 4G network depending on the owner’s location in the US. The ST5 also features a locking system for the motor that adds an extremely uncomfortable level of resistance to the movement of the rear wheel, preventing a thief from pedaling away with it. This system can be deactivated manually through a 5-digit PIN or the Stromer OMNI app, as well as through a “Smartlock” system that automatically unlocks the bike when the bike’s owner approaches it with the app open. Like an automobile, the ST5 has a loud, wailing alarm system that activates if the bike is ridden while turned on and locked. If this happens, theft mode is automatically activated – and an email is sent to the bike’s owner to notify them.
The bike also includes a number of customization options through the OMNI app or the bike’s top-tube-integrated touchscreen display. Users can adjust the sensitivity of the torque sensor, the tuning of PAS Mode 2, the behavior of the regenerative braking system, and more. I’d have preferred the inclusion of a full navigation system through the app, but the ability to get turn-by-turn directions to a service center was appreciated. I’d also like to see Stromer expand the tuning options to all riding modes instead of just Mode 2, but this is a minor critique.
There were a number of other additional features that enhanced the user experience, including the ability to eject and easily remove the battery, the magnetic charging port that effortlessly guided the charger into position, the fast charger itself that refueled the massive battery in 5.5 hours, etc. The bike includes a side mirror for safety and awareness, an electronic horn that’s impossible to miss, and a cargo rack with a 50 lb capacity. Users can even use their phone as a secondary display through the SP connect receptacle that can be attached to the bike’s stem.
There’s a fairly steep learning curve to get the most out of the ST5 – figuring out what all of the settings and functions do, and what your personal preferences are will likely take some time – but the investment is worthwhile. It rides like a dream right out of the box, but I can attest that once it is tweaked and tuned to your liking, it’s tough to put down.
