Bulls Sonic Evo AM SX1 on test: Light and versatile - that's how good the e-bike with Bosch SX motor is
Florentin Vesenbeckh
· 27.08.2024
In the Sonic EVO AM SX Bulls combines practical virtues with a sporty touch. As is usual with the Cologne-based company's e-bikes, a rear light is integrated into the carbon rear and a suitable light can be easily clipped onto the front using the Monkeylink bracket. Battery removal is also designed for convenience and suitability for everyday use, as the Bosch Compact Tube 400 is secured with a lock and can be conveniently removed to the side. Unfortunately, the plastic cover is very awkward to close. Nevertheless, a removable battery is not a matter of course for light e-bikes. A big plus on the checklist for the Bulls Sonic EVO AM SX1.
The carbon chassis is sporty, reducing the weight of the e-bike to 19.6 kilos. This makes the Bulls Sonic EVO AM the lightest bike with a removable battery in our comparison test of seven light E-MTBs up to € 6600! The sporty, stretched riding position and the fast-rolling tyres make the E-MTB a snappy speedster for fast laps on unpaved paths. In keeping with this, the equipment with trail fork and shock without reservoir is rather tame.
The facts about the Bulls Sonic Evo AM SX1
- Motor: Bosch Performance Line SX, 55 Nm max. torque
- Battery: 400 Wh (removable)
- Frame material: Carbon
- Spring travel: 140 / 130
- Wheel size: 29 inch
- Frame sizes: S, M, L, XL
- Price: 5999 Euro
- Weight: 19.57 kg (test bike in size L, EMTB measurement)
- Permissible total weight: 130 kg (manufacturer's specification)
The e-bike drive
On the motor side, Bulls Sonic EVO AM has opted for the Performance Line SX from Bosch decided. Compared to many other light engines such as the Fazua Ride 60 or the TQ HPR50 rather large. In terms of weight, however, at 2.1 kilos it keeps up well with the competition. It is also significantly more powerful than the classic light competition, at least in terms of pure top performance. With lively acceleration and top modulation, it brings a lot of dynamism and riding fun uphill. At low cadence, however, the SX is not particularly powerful. It lacks a little torque here. It only delivers its high performance at a very high cadence. Too bad: On the trail, the Bosch Performance Line SX rattles out of the gearbox.
The Bosch Compact Tube 400 provides the power for the SX and, as usual with Bulls, the battery can be conveniently removed from the side of the down tube and is secured with a key. Unfortunately, the plastic cover can only be removed with difficulty, which penalises the otherwise very convenient removal. To operate the motor, Bulls relies on the combination of a Bosch system controller and a wireless mini remote on the handlebars.
The geometry
The slim carbon chassis has more classic dimensions and is clearly designed for touring. The long top tube and the not-too-steep seat angle provide a sporty riding position, while the rather steep steering angle ensures neutral handling. Thanks to the low bottom bracket and long reach, you still feel secure on the bike.
EMTB measurements at a glance (frame size L)
- Seat tube length: 460 mm
- Wheelbase: 1258 mm
- Reach: 469 mm
- Stack: 656 mm
- Steering angle: 65.5 degrees
- Seat angle: 75 degrees
- Chainstay length: 448 mm
- Bottom bracket height: 326 mm
The equipment of the Bulls Sonic Evo AM SX1
The components on the Bulls can't quite stand up to comparison with the competition at this price point. Inexpensive Suntour suspension with Bulls branding, Shimano brakes with levers that are too long and Schwalbe tyres from the affordable Performance line - there's not much to get excited about. These compromises have to be made in favour of the high-quality carbon chassis.
- Fork / shock: SR Suntour Lytro 34 SL / Edge Plus
- Gears: Shimano Deore, 12-speed, 34; 10-51 teeth
- Brakes: Shimano MT420, 203/203 mm
- Wheels: Mavic E-Crossride
- Tyres: Schwalbe Nobby Nic Performance / Wicked Will Performance, 29 x 2.4''
- Special features: Integrated rear light, Monkeylink mount for front light, convenient battery change
Practical test: How the Bulls Sonic Evo AM SX1
The sporty, stretched seating position makes it clear that Bulls has not created a comfort tourer here. In keeping with the sporty SX motor, the overall package of the Bulls Sonic Evo AM is also designed for fast tours and motivated riders. Even without switching on the motor, the bike makes rapid progress - not least thanks to the fast tyres. On flat terrain, you really make up metres.
On steeper climbs, the longer chainstays put pressure on the front and the bike climbs easily. For technical sections, however, you sit too far back, which makes control more difficult. The suspension is sporty and firm and prioritises direct propulsion over plush comfort. This also applies downhill, where you can effectively push over bumps and through berms on flow trails. If the terrain gets rougher, the SX1 allows you to engage the brakes much earlier than the competition. The stiff suspension is a particular hindrance, as it provides little traction and cannot filter out bumps as effectively. The brakes and tyres are also quickly overwhelmed. We believe that the better-equipped AM-SX models have significantly more downhill potential.
EMTB evaluation of the Bulls Sonic Evo AM SX1
Strengths
- Lightweight, despite quick-change battery
- Fast and sporty on flat courses
- Integrated lighting solutions help in everyday life without being a nuisance
- Large dealer network
Weaknesses
- Moderate equipment
- Quickly overwhelmed in difficult terrain
- Engine rattles
The EMTB conclusion
With its tame spec, the Bulls Sonic EVO AM SX1 is clearly designed for touring and moderate terrain. On the trail, the favourable parts are limiting. Top: Smart everyday features and a high-quality frame with removable battery. - Florentin Vesenbeckh, Test Manager EMTB Magazine
Florentin Vesenbeckh
Editor CvD
