Stromer aren’t new to the s-pedelec game, but the Swiss brand are shifting up a gear with the ST3. The Pinion gearbox is a first for them, which they’ve combined with a GATES CARBON DRIVE belt, keeping the bike looking clean and promising a low-maintenance experience – with mixed results.

Stromer ST3 | 33.02 kg | € 8,158.00 | Manufacturer’s website

Energy source – The Stromer ST3 comes with a huge battery

The Stromer ST3 Pinion certainly doesn’t look like an ordinary ebike: everything looks a little bit bigger, beefier and stronger. For example, the SYNO Drive II motor looks massive compared to the compact hub motors you’ll find in regular pedelecs. Although the motor’s 44 Nm torque isn’t much, it’s capable of regenerative braking and puts out a whopping 820 watts. The removable 983 Wh battery is big, too, and its considerable size determines the shape of the down tube to a large extent.

The remaining tubes on the frame are oversized to match, which makes for a balanced looking design together with the fat 2.35″ tires. It doesn’t make the impression of a slow and cumbersome cruise ship, but rather a sporty hybrid between a motorcycle and bicycle with a futuristic touch. This is particularly evident in the high degree of integration: the daytime running light in the head tube, internally routed cables and seamlessly integrated display in the top tube show that Stromer set out to create the most modern and stylish bike they could.

The brain of the ST3: the OMNI C display in the top tube offers numerous functions and can also be connected to your smartphone via the OMNI app.
Together with the OMNI C display, the daytime running light in the head tube adds to the bike’s futuristic look.
The remote for the electric motor (left) and the twist grip shifter (right) on the cockpit of the ST3 are intuitive to use. As such, you’ll rarely have to look at the display while riding.
The Stromer ST3 Pinion looks balanced and sporty despite the oversized tubing of the frame.

This design brief flows over into the drivetrain, combining a 9-speed Pinion C-Line gearbox with a GATES CARBON DRIVE belt, which doesn’t just make for a clean look but a physically clean bike – after all, the belt doesn’t require any lube.

Good and bad: the Pinion gearbox offers a wide gear range, but the side stand can’t cope with the bike’s considerable heft.
A low-maintenance team: the Pinion gearbox in the bottom bracket is paired with a GATES CARBON DRIVE belt.
The SYNO Drive II in the Stromer looks huge compared to other hub motors, but therefore it’s capable of regenerative braking.

The low-maintenance drivetrain and standard accessories, including lights with a high beam function, mudguards, luggage rack and side stand, should be particularly convenient for commuters. While the components make a very high-quality and robust impression overall, the side stand doesn’t seem very reliable considering the bike’s weight. Speaking of which, the ST3 tips the scales at a whopping 33.02 kg, which is very noticeable in certain situations. You’ll certainly have a hard time carrying the bike up and down the stairs!

From 0 to 45 and back – Taking the Stromer ST3 Pinion for a ride

The moment you ride the ST3, you’ll quickly forget the bike’s weight. The motor pushes the bike forward relentlessly on level terrain, and you’ll reach the 45 km/h limit almost effortlessly, at which point the motor stops assisting, as required by European regulations. The motor cuts out gently, but you’ll struggle holding the pace above this limit with only your legs – there’s just too much wind resistance.

You get a big 203 mm rotor at the rear, though you’ll only need it during hard stopping manoeuvres thanks to the motor’s regenerative braking.
Road legal: as with all s-pedelecs, you’ll need a registration plate when riding the Stromer ST3 on European roads.

We were impressed with how quiet the bike is, which isn’t just thanks to the hub motor in the rear, but also the GATES belt and Pinion gearbox. Thanks to the twist grip on the handlebar, the latter can be shifted effortlessly and offers a wide 568% gear range, which – in theory – should make easy work of steep climbs.

However, the ST3 gave up on gradients of over 10% during our test rides, which is due to the hub motor in the rear wheel. At low cadences, its support occasionally cut out completely, making it impossible to conquer the climbs even in the easiest gear – this is when you’ll definitely feel the ST3’s weight. After speaking with Stromer, they confirmed that the problem can be resolved. That said, we don’t know whether the software update will also improve the motor response. However, compared to current mid-mounted models, the motor in the ST3 feels a bit sluggish, kicking in and cutting out with a slight delay. The Pinion gearbox wasn’t flawless either, as the shifting was occasionally accompanied by a clearly perceptible crunch.

The ST3’s removable battery provides a long range thanks to its huge 983 Wh capacity.
Of course, you can also charge the battery on the bike via the integrated charging socket.

One of the more positive aspects of the motor, on the other hand, is that it’s capable of regenerative braking. You can adjust the level of regeneration, which determines how much the motor brakes and thereby recharges the battery when you’re coasting. Although the increased range is rather insignificant given the huge battery, you’ll quickly learn to appreciate the braking function of the motor with a pre-emptive riding style – especially since this also results in less wear on the actual brakes. Speaking of which, these are supplied by TRP and offer plenty of braking power thanks to large 203 mm rotors on the front and rear, for those hard braking manoeuvres.

GPS, alarm system and app – The smart features of the Stromer OMNI C display

The motor gets controlled via the large OMNI C display, which, besides displaying the current riding information, also features smart functions such as an alarm system and GPS tracking. You can use it to adjust the three support levels of the motor as well as the level of regenerative braking. Last but not least, the display can also be connected to Stromer’s OMNI app on your smartphone, which allows you to track the bike’s location.

Due to the position of the display on the top tube, it forces you to take your eyes off the road, which is certainly a disadvantage, especially considering the high speeds of an s-pedelec. However, thanks to a compact remote on the handlebar, you can operate the motor just as intuitively as the Pinion gearbox with its twist grip shifter. As such, you’ll hardly have to look at the display while riding.

The fact that Stromer are targeting urban commuters with the ST3 is further underlined by the riding comfort. By dispensing with any active suspension elements, the tires are the only source of cushioning on bumpy roads. The Pirelli Cycle-e ST tires are capable of serving this purpose to a certain extent, though they reach their limits on very bad roads strewn with potholes. In that case, impacts get transferred up the rider’s spine largely unmitigated, particularly at high speeds. It’s a good thing that Stromer have a suspended seat post and suspension fork available as an optional extra. While they detract from the bike’s clean look, we highly recommend these upgrades for comfort-seeking riders!

The 2.35″ wide Pirelli tires are the only source of damping and comfort – on bumpy roads, you’ll wish you had the suspension upgrade.

Our conclusion on the Stromer ST3 Pinion

The Stromer ST3 Pinion is a beautifully designed and great looking s-pedelec, capable of tackling long-distances thanks to the huge battery. We hope that Stromer will soon remedy the motor’s weak performance on the climbs, as we were impressed with it and its regenerative braking on the descents. The same applies to the OMNI C display with its smart functions. It’s one of the Stromer’s unique selling points and underscores the bike’s futuristic look.

Tops

  • futuristic design
  • smart tech features
  • low-maintenance drivetrain and regenerative braking

Flops

  • motor cuts out on steep climbs
  • lack of comfort on poorly maintained roads
  • heavy

Who is and isn’t this bike for?

  • design is one of your top priorities? Then the ST3 is just your thing!
  • commuters will appreciate the low-maintenance drivetrain
  • those who want a comfortable ride must choose the optional suspension upgrade
  • there are better motors for steep climbs

Tuning tip: suspended seat post and suspension fork

Words: Oliver Gibler Photos: Peter Walker