Bulls Sonic Evo EN SL 1 short test: Lightweight all-rounder at a fair price

At the latest since Bosch the new Smart System and the long-range 750 battery has been introduced, people have somehow come to terms with it: Bikes are either extremely expensive or heavy or the battery is permanently installed. However, with the Sonic SL line, Bulls has been proving for several years thatthat these supposed opposites are by no means mutually exclusive. Incidentally, the engineering firm ADP, which also designs the Rotwild bikes, is behind the design of the bike. The similar silhouette like the expensive R.X 735 is no coincidence, but the price tag on the Bulls Sonic SL remains much more moderate.

The carbon e-bike from Bulls with Shimano motor has already convinced us in several tests and even secured the trail tip in the 2022 enduro test thanks to its balanced handling. The elegant EN SL 1 with the new Shimano motor and XT DI2 gears (RRP €6699) is currently often available online for less than €5000, in some cases for less than €4000. Is this the price-performance hit of the season? We find out in this short test.

The facts about the Bulls Sonic Evo EN SL 1

• Motor: Shimano EP801, 85 Nm max. torque
• Battery: 725 Wh (removable)
• Frame material: Carbon
• Suspension travel: 160 / 150 mm
• Wheel size: 29 inch
• Frame sizes: S, M, L, XL
• Price: 6699 Euro (RRP)
• Weight: 22.2 kg (test bike in size L, EMTB measurement)
• Permissible total weight: 130 kg (manufacturer's specification)

New Shimano motor with more power

Thanks to the update to the EP801 (here in the test) the Sonic EN SL 1 also benefits from an increase in power compared to its predecessor. Especially at medium cadences, the Japanese motor pushes almost as hard as the CX from Bosch, but remains significantly lighter. The disadvantage of the Japanese motor is the less lively power delivery. The assistance can be customised to personal preferences via an app. Shimano's high-quality EM800 display provides the most important information.

Like its competitor Rotwild with the technically similar R.X 735, Bulls relies on its own battery with a carbon outer casing. The battery offers 725 watt hours, but weighs only 3.6 kilograms and can be conveniently removed from the side. That's great for an e-MTB in this weight class. The only drawback: the battery release on the down tube is often a little stiff and gets covered in dirt every time you ride.

The geometry - handy and easy to master

The carbon frame of the Bulls Sonic Evo EN SL 1 has a rather classic design. Only the 64.5 degree head angle is reasonably modern, but the reach is rather short, as is the wheelbase. Full-throttle fans who expect maximum directional stability are likely to be disappointed by the Bulls. However, anyone looking for a playful and manoeuvrable e-bike for trails will find the compact dimensions and in particular the rather short chainstays an advantage. Only the seat tube could really be a little shorter, so there would be more room for riders with short legs who still don't want to do without long dropper posts.

EMTB measurements at a glance (frame size L)

• Seat tube length: 460 mm
• Wheelbase: 1250 mm
• Reach: 454 mm
• Stack: 653 mm
• Steering angle: 64.5 degrees
• Seat angle: 75.5 degrees
• Chainstay length: 448 mm

XT-Di2 with Free- and Auto-Shift: The equipment of the Bulls Sonic Evo EN SL 1

The gearing on the Sonic Evo EN SL is where Bulls reaches for the top shelf. The Shimano XT Di2 shifts electrically and is supplied with power by cable from the main battery. The only eleven gears of the top Japanese drivetrain are only a disadvantage compared to twelve-speed drivetrains on paper. In practice the eleven-fold version, called Linkglidewide gradation and shifts more smoothly under load. In combination with the less delicate components, this means that a longer service life can be expected. A sensible combination, especially on E-MTBs.

>> The gearstick can also change gears on the move (Free-Shift) or even fully automatically. We tried out how this works in practice in the Auto-Shift reader test.

The rest of the equipment comes from the middle shelf. The Lyrik fork delivers a solid performance, the Super Deluxe shock comes with lockout and reservoir. The somewhat heavy Deemax wheels from Maxxis and the Deore brakes are not a highlight, but functionally there is little to complain about. All in all, a fair package even at the RRP, especially as a lot of money has gone into the lightweight frame. Monkey Link interfaces increase the practical value in everyday use.

• Fork / shock: Lyrik Select / Super Deluxe Select+
• Shifting: Shimano XT Di2 Linkglide
• Brakes: Shimano Deore
• Wheels: Mavic E-Deemax
• Tyres: Schwalbe Magic Mary / Big Betty, Supertrail Soft, 29 x 2.4"
• Special features: Gearstick with auto-shift function, easily removable carbon battery, Monkey-Link interfaces.

Practical test: How the Bulls Sonic Evo EN SL 1 rides

The Bulls has a sporty and comfortable seat, the not too aggressive geometry, namely the moderate seat angle and the slightly higher stack make the Sonic Evo EN SL a good partner for longer tours. The range of the bike also fits in with this, which is in the good mid-range with 725 watt hours. Only Bosch's 750 watt-hour battery and a few specialists with around 900 watt-hours can really up the ante here.

The Bulls E-MTB performs well on climbs and can be controlled neutrally. The suspension doesn't bottom out even on steep sections and provides good traction. However, the e-bike requires an active riding style on very steep terrain - after all, the Bulls is not a long-travel lorry with long chainstays. The Shimano motor delivers a decent punch, but is not very lively on demanding uphills.

The Bulls Sonic Evo's speciality: downhill fun on gentle to moderately difficult trails. The home circuit in the low mountain range, flow trails and smaller jumps, easier enduro trails - this is where the e-bike really feels at home and impresses with its neutral and direct handling. Thanks to its low weight, the EN-SL is easy to push into corners and pull into the air. This is impressively good for an e-bike with full motor power. The Bulls retains its direct character even when the terrain gets rough. If you want to hit the rocks at high speed, you need a steady hand and solid riding technique. The cleanly tuned rear suspension still cuts a fine figure here, but the geometry, fork and brakes slowly reach their limits.

EMTB review of the Bulls Sonic Evo EN SL 1

Strengths

• Driving behaviour fun and easy to handle
• Chassis confident and balanced
• Lightweight, despite simple battery removal
• Price-performance ratio

Weaknesses

• Battery release partly stiff
• Engine rattles

The EMTB conclusion

Contrary to what the name suggests: The Bulls is not an explicitly swallowing E-Enduro. However, the Sonic Evo EN SL cuts a really good figure as an all-mountain bike for touring and challenging terrain. The well-balanced chassis and the fun handling score points. With its low weight and practically removable battery, the Bulls also outperforms many significantly more expensive bikes. Even more so at current prices. A clear recommendation for trail and touring bikers! - Adrian Kaether, test editor at BIKE and EMTB