Wow, how cool is that? Some of you may have said this when you first saw a mountain bike with a suspension fork that only has one leg. Cannondale, a pioneer in this field, presented the Raven 4000 SX, the first model with such a Lefty, in the 2000 season. Ebike manufacturer Electrolyte apparently liked the idea quite a bit. However, they went one step further and integrated an ebike drive into a rigid Lefty. You can ride it on the Electrolyte Straßenfeger S4E.
1. What kind of ebike is the Electrolyte Straßenfeger S4E?
2. Why did Electrolyte opt for a single-sided swing arm for the Straßenfeger S4E?
3. What are the advantages of a single-sided swing arm for frame construction?
4. What kind of frame is this ebike based on?
5. How does Electrolyte compensate for the left-heavy weight distribution caused by the Lefty, including the ebike battery, on the Straßenfeger S4E?
6. What characterises the front-wheel drive?
7. How are the two riding modes coordinated?
8. What performance does the motor promise?
9. How can the ebike battery be charged?
10. What versions of the Straßenfeger S4E does the manufacturer offer?
11. Which accessories could be particularly interesting?
12. Who is Electrolyte?
1. What kind of ebike is the Electrolyte Straßenfeger S4E?
The Straßenfeger S4E from Electrolyte is an urban ebike featuring a belt drive. However, it is not just any city ebike. With its motor located in the front wheel, it differs from what the majority of ebike manufacturers currently offer in the segment starting at around 3,500 euros. And that’s not even its most obvious special feature. That would be its fork, which stands out with its single, solid leg. This houses the motor, battery and controller. Electrolyte refers to the design as a single-sided swing arm.
Anyone who thinks the Straßenfeger S4E is a new model is very much mistaken. The first version of this ebike was launched back in 2012. The current series is limited to 60 units, so we are definitely talking about a rarity here.
2. Why does Electrolyte rely on the concept of a single-sided swing arm for the Straßenfeger S4E?
This solution allows a pedelec drive to be integrated into a single component. This gives the manufacturer maximum flexibility when building an ebike. It doesn’t matter whether the end result is a city ebike, touring bike or compact ebike with 20-inch wheels. The single-sided swing arm paves the way for a lightweight, fully-fledged ebike.
3. What are the advantages of the single-sided swing arm for frame construction?
The bicycle frame for an ebike such as the Straßenfeger S4E from Electrolyte does not require a motor mount on the bottom bracket for the mid-drive motor or a down tube suitable for integrating the battery. This means that, apart from the single-sided swing arm, its appearance is as purist as a bicycle without an electric drive. This gives the manufacturer almost complete freedom to choose which materials and geometries to work with.
4. What kind of frame is this ebike based on?
The 7020 aluminium frame for this ebike comes from a small manufacturer in Pilsen, Czech Republic. Electrolyte has the weld seams ground by hand there. Thanks to this detail and its thin tube diameter, it looks high-quality and fits in with the sporty approach of the Straßenfeger S4E. The manufacturer offers the frame in three sizes: S, M and L. This means it should be suitable for people with a height of 160 centimetres to 195 centimetres. If you have very specific ideas about how the frame for your ebike should look, Electrolyte can help you realise them. For an additional charge of around £450, you can have the frame manufactured based on your personal measurements.
Thanks to its aluminium frame, the ebike weighs around 16.2 kilograms without mudguards, rear rack and side stand.
5. How does Electrolyte compensate for the left-heavy weight distribution caused by the Lefty, including the ebike battery, on the Straßenfeger S4E?
According to the manufacturer, a reinforced front part of the frame absorbs any potential negative effects of the swing arm on handling. The geometry of the fork is the same as that of a normal bicycle fork. As there is hardly any change in terms of the pivot point, the steering behaviour remains almost the same as that of a bicycle with a conventional fork.
The difference is only noticeable when riding hands-free.
6. What characterises the front-wheel drive?
In our opinion, two features of the Electrolyte motor stand out in particular:
The position: Most of you are probably familiar with the mid-drive motor and rear wheel hub motor found on modern ebikes. Relatively few manufacturers still use a motor on the front wheel these days.
The bimodal design: Electrolyte treats riding with and without motor assistance equally in the Straßenfeger S4E. This means that when switched off, the motor is completely decoupled from the actual bicycle, so that no resistance slows down the ride. At the same time, the turbo button provides a shortcut of sorts, allowing you to switch on the electric assistance immediately at any time as long as you are pedalling.
7. How are the two riding modes coordinated?
The first mode is designed as standby for the electric drive. Basically, you ride as you would on a regular bike. If you press the turbo button while pedalling, you can access the full power of the ebike system at any time.
The second mode is the actual pedelec mode. Divided into four assistance levels, the motor supports you up to a maximum specified power output. This is done dynamically based on cadence and speed. From each of the levels, you can press the turbo button again to access the peak power output. If the front wheel briefly loses traction as a result, the drive detects this and automatically reduces its power.
8. What performance does the motor promise?
As a motor for a pedelec, Electrolyte’s in-house development delivers the familiar 250 watts in continuous operation. It uses an encapsulated design. Inside, a two-stage planetary gearbox provides the appropriate transmission ratio. The manufacturer itself states that you will hear a noise from the motor when it is activated. Unfortunately, we cannot say how loud, noticeable or what pitch it is, as we have not yet been able to take the Straßenfeger S4E for a spin ourselves. With so much openness, we strongly assume that the figures for torque of 23 Newton metres and weight of 1.5 kilograms are accurate as well.
9. How can the ebike battery be charged?
Given the single-sided swing arm, some of you might assume that the battery is permanently installed. In fact, however, it can be removed. Unlike other lightweight urban ebikes such as the Scott Silence eRide or the Velo de Ville Revo-C, you can conveniently charge the battery in your own home. Its weight of around 1.8 kilograms does not make this particularly difficult. Alternatively, you can also charge it directly on the ebike.
After three hours, the 356 watt-hour battery should have regained its full capacity. Depending on your riding style, weather conditions, route profile, tyre pressure, load and so on, you can expect a range of at least 45 kilometres. Under particularly favourable conditions, even 100 kilometres should be feasible.
10. What versions of the Straßenfeger S4E does the manufacturer offer?
Electrolyte primarily designed this model as a sporty ebike that shows its strengths when riding in urban environments. For the drive, you can choose between a single-speed hub with coaster brake and a 2-speed kick-shift hub with coaster brake. The latter shifts between gears by briefly pedalling backwards without applying the brake. The impulse activates the shifting process. This solution therefore does not require a shift lever on the handlebars.
The basic equipment for the price of 3,790 euros does not include mudguards, a side stand or a rear rack. However, these can be added in the configurator on the manufacturer’s website during the ordering process. Electrolyte has designed this personalisation to be extremely comprehensive and detailed. From your desired colour and suspension seat posts to different tyres, a Bikefinder GPS tracker or various folding locks from Abus, there are many options available. By switching to an 11-speed hub gear, you can even turn the Straßenfeger S4E into a touring bike. With this drive variant, the starting price increases to 4,180 euros.
11. Which accessories could be particularly interesting?
For 129 euros, you can even equip your dream ebike with a charging port for mobile devices. The manufacturer not only developed the PowerRing itself, but also produces it in-house. It is placed under the stem on the steerer tube. The power comes directly from the electric drive. The USB-C port supplies your smartphone with a maximum charging power of 15 watts.
12. Who is Electrolyte?
If you haven’t heard of this manufacturer before, there’s no shame in that. Since 2009 ebikes have been produced at the company’s headquarters in Piusheim near Munich. However, Electrolyte sees itself as a craft business and has specialised in small series production. In return, it upholds its identity as a manufacturer that gives great importance to the individual wishes of its customers.
Electrolyte sells its models exclusively through direct sales. So you won’t find this brand in a typical bicycle shop. If servicing is required, the manufacturer will send its own employees to your home or arrange for the bike to be collected for repair.
Electrolyte Straßenfeger S4E at a glance
- Frame: aluminium
- Frame sizes: S, M, L
- Motor: Electrolyte
- Battery: Electrolyte, 356 Wh
- Control unit: Electrolyte LED with turbo button
- Drivetrain: Single speed with coaster brake, Sturmey Archer 2-speed hub gear, Shimao Alfine 11-speed hub gear
- Brakes: Magura MT4 eStop
- Weight: approx. 16.2 kg
- Maximum permitted total weight: 140 kg
- Prices: from 3,790 euros
Pictures: Electrolyte GmbH