This bike is the clear rebuttal to the unassailable theory that "e-biking is for older and lazy people". This is what makes it really fun: engage the first of only two gears, cadence up - and off you go! That's right: the SL brings vigour to everyday life. It starts with the look: The aluminium frame has a clear and minimalist design. Our model looks sporty and elegant in the "Anthracite Gloss" paint finish, but also trendy thanks to the second colour on the top and down tube.
The straight (carbon) fork, a sloping top tube and the small rear triangle create a sporty silhouette. The stiff handlebar/stem combination of the Flyer Upstreet SL accommodates cables and wires, creating an even tidier appearance. Only the colour-contrasting sidewalls of the Vittoria tyres have a retro flavour that may be too much for some.
Flyer Upstreet SL: High-tech and design
Getting on: There's not much to adjust, the suspension seat post and adjustable stem are dispensed with in favour of weight. So adjust the saddle height and off you go. The riding position on the almost straight handlebars is quite sporty, but not too stretched, the cockpit is tidy: only the bell and brake lever are on the right, a small ring next to the left grip is used to shift gears intuitively. Turn forwards: low gear, backwards: high gear. Next to the shift ring is the barely larger control unit for the motor support.
If you want a display, you can also use your mobile phone with the Bosch app, which gives you many more display and setting options. The motor is switched on and off on the top tube panel, where five LEDs also indicate the charge status of the Performance Line SX. This new motor is intended to help the drive manufacturer gain a foothold in the lightweight e-bike class (up to 20 kilos). The system includes a battery with a capacity of 400 watt hours in the down tube of the SL. Four modes: Eco, Auto, Sport and Turbo. We enjoyed the new Auto mode the most and it best reflects the characteristics of the XS with the Bosch Smart system.
Motor and drive
"Let Bosch do it" is the wrong mindset: The SX delivers rather little power at a low cadence. The new model is an athlete for the fleet. Those who ride at frequencies of over 65 per minute are rewarded with a turbine-like thrust. This also means that more power is required at traffic lights than with other motors. But then it really gets going, also thanks to the low weight of 17.8 kilograms. Even though there are only two gears, you need to start off in low gear if you want to get up to speed quickly and get plenty of support.
Are the two gears enough? Yes, if you prefer sporty to comfortable. The electronic shifting with Classified is a real pleasure, shifting in real time and even under load is stress-free. The Flyer Upstreet SL is a real joy in intermediate sprints or when the city gets hilly. That's when the SX really gets going - the little bike delivers a whopping 600 watts of peak power with a nominal torque of just 55 Newton metres.
Great: In Auto mode, it always provides the right support automatically. If you pedal faster, you get a crisp boost more quickly. The SX motor is much more audible than the Active drives from the same manufacturer. However, the noise is not disturbing. In general, we found the new drive to be the most harmonious Bosch to date in terms of its co-operation with its "own drive". Flow is virtually standard here. If you want to, you can easily roll along on the flat without assistance and save energy, as there is hardly any resistance in the system.
Commuting, excursions, short tours - areas of use for the new Flyer e-bike
The sporty Upstreet SL is surprisingly happy to go straight ahead. The wide tyres want to be pushed into the bend, but then you can quickly get into a lean angle. If you get used to it, it rolls manoeuvrable through the city and is also smooth on tour. The equipment of the Flyer Upstreet SL is perfect for commuters and short tourers: the nicely integrated carrier with a load capacity of 15 kilograms takes what is needed, the permissible total weight of 130 kilograms should be suitable for many uses and riders.
The wide Vittoria tyres with smooth centre tread offer low rolling resistance, but can be used for a wide range of applications thanks to the side lugs. However, only real sports enthusiasts are likely to ride significantly faster than 25 metres for longer, as the gear ratios are short. The Tektro discs tame the propulsion crisply and with good modulation, even with luggage. The Flyer-labelled 100-lux spotlight is also great for everyday use. It has a range of around 70 kilometres on mixed terrain in Auto mode.
If you're up for it, you can get over 100 kilometres with less assistance and on mainly flat terrain even with the 400 battery. A range extender with 250 watt hours can be retrofitted. 5899 euros is no bargain, but is realistic in view of the high-tech and high quality. However, a longer test ride with the lightweight sports bike should clarify whether you will be happy with two gears in your area of use before you buy.
Conclusion from Georg Bleicher, MYBIKE test editor
The Flyer SL 3.63 is a pedelec for sporty bikers who previously found e-bikes too boring or too heavy. The motor dynamics are impressive, as is the low weight. You have the impression of sitting on a crisp sports bike and suddenly being much more trained yourself.
The most important information about the Flyer SL 3.63
- Price: 5899 Euro
- Frame sizes: S, M, L, XL (mixed frames also available)
- Frame: Aluminium
- Weight: 17.8 kilos
- Permissible total weight: 130 kilos
- Brakes: Disc, Tektro T280 180/160 mm
- Suspension fork: Carbon, FLYER Rigid Fork
- Circuit: Classified Powershift, 2-speed hub gears, Gates belt
- Tyres: Vittoria Terreno Zero Classic Skin 47 - 622
- Motor / battery: Bosch Performance Line SX Smart System
- Front / rear lighting system: Flyer One HL-2, 100 Lux, with LED daytime running light / Lezyne Fender
- Maximum load of the carrier: 15 kilos
