Bulls Sonic EVO AM SL1 on test: How good is the affordable lightweight after the update?

For a long time, e-mountainbikes with classic power motors only developed in one direction: a large battery with a massive range - but also a corresponding excess weight! The Sonic EVO AM SL from Bulls was an exceptional exception in 2022. With a large 725 battery and classic Shimano motor, the bike weighed in at a slim 21.5 kilos. And for a good 5000 euros! Such combinations were actually reserved for the absolute high-end league. The bike thus made its way straight into the hearts of EMTB readers: The Bulls Sonic EVO AM SL 1 took first place in the vote for E-Touring Bike of the Year 2022! But the lightweight setup had a catch: The equipment was minimalist, the tyres and the suspension limited the off-road capability a little. A shock on serious trails. And that's exactly what Bulls wants to change with the new 2024 edition.

What has remained is the elegant and lightweight carbon chassis, with the large but lightweight battery embedded in the down tube. However, the suspension travel has been increased from 140 to 160 millimetres thanks to different suspension elements. In addition, the tame Nobby Nic tyres have been replaced with high-profile Magic Mary tyres. The key data therefore points less to gentle touring, but almost to enduro! We have extensively tested how the bike performs off-road.

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• The Haibike Nduro 8 Freeride on test: A clear edge for rough daredevils
• The Husqvarna Mountain Cross MC5 on test: Stylish all-mountain bike with motorbike DNA?
• Testing the Olympia Hammer CC04: Italo underdog as an e-bike high-flyer?
• Rockrider E-EXPL 520S test: Does Decathlon build the best e-bike fully for under 3000 euros?
• Scott Patron ST ERIDE 900 Tuned on test: The new Scott - the ultimate all-mountain E-MTB?
• An overview of the test of our readers' dream bikes can be found here

More suspension travel, thicker fork, thicker tyres: The update is intended to give the Evo AM SL 1 more riding safety and reserves. But at the same time, the bike has gained more pounds, logically. At 23 kilos, it is definitely still on the light side for a bike costing around 5000 euros with a large battery. Weights over 25 kilos are the norm in this class. However, it is a full 1.5 kilos away from its predecessor from 2022. Of course, puncture protection and grip qualities don't come for free.

The facts about the Bulls Sonic EVO AM SL1

• Motor: Shimano EP6, 85 Nm max. torque
• Battery: 725 Wh (removable)
• Frame material: Carbon
• Suspension travel: 160 / 160 mm
• Wheel size: 29 inch
• Frame sizes: S, M, L, XL
• Price: 5199 Euro >> e.g. available at Radonline
• Weight: 23.1 kg (test bike in size L, EMTB measurement, without pedals)
• Permissible total weight: 130 kg (manufacturer's specification)

The e-bike drive

The Bulls Sonic EVO AM SL 1, which we tested at the end of 2021came with Shimano's EP8. In the meantime, the Japanese company Shimano has extensively modernised its motor. The EP801 has become more powerful and has also been given a little brother. And it is precisely this EP6 that is in the new edition of the EVO AM SL 1. This cheaper motor is visually identical to the EP801 and EP8, but does not have a magnesium housing. This makes it around 300 grams heavier than the 8 series. Unfortunately, it is also not on a par with the EP801 in terms of performance. The "small" Steps is said to deliver 100 watts less and is therefore more on a par with the old EP8. This is also noticeable in practice.

Part of the secret of the low weight of the Bulls Sonic Evo AM SL is the battery. The battery delivers 725 watt hours at a weight of 3.55 kilos. That's a really strong figure. A Bosch Powertube 750, for example, weighs 4.3 kilos! The battery is removed from the side/top of the down tube. You don't need a spanner or tools to do this. However, removing the battery is a bit tricky. At least when it is adjusted so tightly that the battery doesn't rattle. While we had to criticise a very annoying battery rattle in previous tests with this design, the current bike did not cause any significant problems here.

The geometry of the Bulls Sonic EVO AM SL1

Despite the change in suspension travel, the geometry of the Sonic Evo AM SL 1 has hardly changed. In other words, the character remains more tour-orientated, so the bike is not a true enduro bike despite the 160 mm travel. The steering angle is too steep and the wheelbase too short. As a result, the bike remains manageable and balanced and cuts a fine figure even when ridden at a moderate pace.

EMTB measurements at a glance (frame size L)

• Seat tube length: 460 mm
• Wheelbase: 1250 mm
• Reach: 454 mm
• Stack: 653 mm
• Steering angle: 65 degrees
• Seat angle: 76 degrees
• Chainstay length: 451 mm

The equipment of the Bulls All Mountain E-Bike

If you compare the new 2024 model of the Evo AM SL1 with the bike from 2022the equipment has become somewhat weaker at the same price. Bulls has not only downsized the motor, but also the brakes and gears, which are a little further down the Shimano range. The inexpensive Rockshox suspension gives way to SR Suntour suspension elements. With its 36 mm stanchions, the fork is more robust than the Rockshox 35 and the suspension travel increases from 140 to 160 millimetres. Additional gimmicks such as the magnetic Monkey-Link mount for an optional front light (already connected to the main battery), the Fidlock bottle cage and the SP-Connect smartphone mount offer added value in everyday life and on tour.

• Fork / shock: SR Suntour 36 Zeron / Edge Plus
• Gear system: Shimano Deore, 12-speed, 10 - 51 teeth
• Brakes: Shimano MT 420, 203 / 203 mm
• Wheels: Shimano hubs, Rodi Tryp 30 rims
• Tyres: Schwalbe Magic Mary Performance, 29 x 2.4 inch
• Special features: Monkey-Link mount for front light, Fidlock water bottle holder

Practical test: How the Bulls Sonic EVO AM SL1

Sit up and feel good - that still applies to the Bulls Sonic Evo AM SL 1! The absence of extreme geometry makes the riding position and handling balanced and neutral. The steering doesn't tip over and the rider is positioned centrally between the axles. The body posture is slightly stretched and sporty.

The uncomplicated character continues uphill, with the somewhat weaker motor only limiting the climbing ability in very difficult sections. The bike only needs to be ridden actively on steep ramps and follows steering movements very directly. The rear suspension provides a lot of comfort and traction. On wet rocks and roots, however, the inexpensive version of Schwalbe's Magic Mary tyres can't build up enough grip. On loose ground, however, this is less of an issue, as the pithy tread can grip well.

It doesn't take long to get used to on the downhill either. The handling of the Bull is intuitive and balanced, a successful compromise between smoothness and agility. Behind the handlebars of the Sonic Evo AM SL 1, there's no need to worry about winding trails or rough sections. The latter, however, put the suspension to the test. At moderate speeds, the bike rolls effortlessly over obstacles. At high speeds, the SR Suntour suspension elements can no longer really keep up, and we were barely able to utilise the full travel even with a soft setup. As a result, the suspension feels quite harsh on rough trails. We have experienced much better on E-MTBs in this price range. Despite 160 millimetres of travel, there is no enduro feeling. Compared to its more tame predecessor, the new Bulls is nevertheless a significant update in terms of riding safety, but is no longer quite as light-footed and lively.

There is also criticism for the moderately powerful brakes, which come from Shimano's low-cost segment. The ergonomics of the long brake levers are also not entirely convincing. The tyres also offer potential for tuning. Bulls has specified the favourable performance version of the Magic Mary. On wet stones and roots, as in our test on Lake Garda in December, the traction of the hard rubber is limited. This noticeably limits riding safety. The comparatively low weight and manoeuvrable geometry are positive aspects. The bike does not feel cumbersome or sluggish, but can be controlled intuitively and directly over the trail, even if it is not quite at the level of its significantly lighter predecessor. The suspension also prevents even better marks in the trail rating. It doesn't quite offer the comfort that the suspension travel suggests, but could also be more defined for a poppy riding experience. This worked better on the 140cc predecessor with Rockshox suspension elements.

EMTB review of the Bulls Sonic EVO AM SL1

Strengths

• Lightweight with a large battery and fair price
• Balanced driving characteristics
• Good range

Weaknesses

• Inexpensive tyres with moderate wet grip
• Braking power
• Chassis

>> Would you like a little more? The Bulls Sonic EVO EN SL 2 Carbon on test!

The EMTB conclusion

Elegant and lightweight carbon chassis, large battery, balanced handling characteristics: The Bulls Sonic Evo AM SL 1* offers a solid package at a fair price. Compared to last year's model, it gains a lot in driving safety, but the chassis, brakes and tyres put the brakes on the euphoria in the practical test. Tuning is worthwhile here! The more expensive versions have even more potential: EN for all-mountain to enduro, AM for touring and shallow trails. - Florentin Vesenbeckh, EMTB Magazine