Light motors and small batteries: 6 light motors and mini batteries put to the test
We have tested these models:
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Almost five years ago, e-MTB pioneer Haibike presented its Flyon: a power bike weighing almost 30 kilos, in which a TQ motor with a massive 120 Newton metres of torque raged. The Flyon polarised like no e-bike before it: more motorbike than bicycle, bad for the image of mountain biking - neither the specialist media nor customers were enthusiastic about the monster. Even before the Haibike Flyon had a chance on the market, the Haibike management turned the wheel - and took a completely different direction. The Schweinfurt-based company presented the result last year: the Haibike Lyke, the first light e-MTB with a Fazua Ride 60 drive.
The recent history of the pioneers from Lower Franconia is representative of the development that the e-mountainbike has undergone in recent years. Above all, the sporty clientele does not want to be passively shuttled up the mountain by a bike, but instead wants an e-bike that offers a sporty and agile ride through the terrain. Sensitive motors are just as important as low overall weight and sporty geometries. And the new generation of Minimal Assist motors makes exactly that possible.
The generation of minimal assist engines
By 2022, the light or minimal-assist segment had rather tentatively gained a share of the overall market. The topic really took off when the Fazua Ride 60 and the TQ HPR 50 were introduced last year. Both motors take the light category to a new level. TQ in terms of unobtrusiveness, Fazua in terms of versatility. Both make unimaginably slim bikes possible with compact dimensions.
And the variety in this segment continues to grow. Recently, Specialized, one of the pioneers of the light segment, presented its new power unit: the SL 1.2. And now Bosch also wants to ensure that the trend spreads: with the Performance SX, the market leader has given its blessing to this type of motor. The industry is working on using light motors and bikes to inspire those target groups that have so far been sceptical about the e-trend. We compare the six currently most relevant drives in this test.
Motor power*
The Bosch Performance Line SX is the front runner in terms of performance. The e-bike motor literally blossoms at high pedalling frequencies. However, it only releases its full power when the rider's own effort is above average and then only for a short time. The Fazua drive can also deliver high power for short periods via the boost function (light red bar). The new Specialized motor is still one of the more discreet drives. TQ's HPR 50, which we didn't test in the lab, is on a similar level.
*Determined in the PTLabs test laboratory at the highest support level. Roller dynamometer with power acceptance on the rear tyre.
Torque*
The Bafang motor installed in the Forestal bikes surprises with a torque at power motor level. This explains its striking power delivery. Fazua and EP8 RS follow at a similar level, with Specialized and the new Bosch SX slightly behind. Compared to its predecessor, the Specialized SL 1.2 has made a significant improvement. In practice, the torque is evident at low cadences, i.e. when starting off and on steep terrain.
*Determined in the PTLabs test laboratory at the highest support level. Roller dynamometer with power acceptance on the rear tyre.
Bosch Performance Line SX
Industry giant Bosch is the latest player to enter the light drive segment. The ratio of weight to power is outstanding. At just over two kilos, it is on a par with the competition, and in terms of power, it easily outperforms all other lightweights with its peak output of over 500 watts. Special feature: It only delivers its full thrust for a short time and with above-average rider input. The SX is also extremely responsive to the rider's cadence. With a slow spin, the performance is only moderate. This is also reflected in the reasonably high torque. In key technical sections where the feet can't spin, there are more powerful light motors. However, the response behaviour and modulation of the Bosch SX are outstanding. Too bad: rattles noticeably on the downhill.
Conclusion on the Bosch Performance Line SX:
Extremely lively and powerful, the SX manages the balancing act between light and power engine. The torque is only average, but the response behaviour is outstanding.
- Weight (motor / system)¹: 2.07 kg / 4.14 kg
- Battery sizes: 400 Wh (2.07 kg)¹, 500, 625, 750
- Range extender: 250 Wh
- Torque²: 50 Nm (39 Nm constant)
- Power peak²: 508 W
- Power: 5.5 out of 6 points
- High cadence pull-through: 6 out of 6 points
- Engine sound: 4.5 out of 6 points
Fazua Ride 60
The Ride 60 from Fazua, launched in 2022, is a real jack-of-all-trades. With its high performance, good stability and lively power delivery, it won't disappoint even power-orientated e-bikers looking for a lightweight system. Nevertheless, the weight and ride feel are fully in line with the light class. The relatively large 430 Wh battery provides a top range. A special feature is the boost function: at the touch of a button, the motor then briefly ejects 450 watts - a real benefit for short, steep key sections. The riding experience with the Ride 60 definitely has the character of an e-bike - without being rough. Even at very high cadences, the Ride 60 pulls away, giving the motor a lively feel. With the latest update, Fazua has also made significant improvements to the delayed start and the push assist.
Conclusion on the Fazua Ride 60:
Powerful, stable and long range with low weight, compact size and a lively riding experience. The Fazua is the most versatile all-rounder among the light motors.
- Weight (motor / system)¹: 2.02 kg / 4.24 kg
- Battery sizes: 430 Wh (2.22 kg)¹
- Range extender: 210 Wh
- Torque²: 59 Nm
- Peak power²: 344 W (Boost: 454 W)
- Power: 5.5 out of 6 points
- High cadence pull-through: 5 out of 6 points
- Engine sound: 5 out of 6 points
Forestal F60-S1/Bafang
The underdog from Andorra surprised us with plenty of power and massive torque. The engine releases its power very boldly and somewhat rudely. In nitro mode, it pushes off fully even with the slightest rider input. The modulation could be better. Impressive: full e-bike feeling with low weight and compact dimensions! Unfortunately, the volume is also correspondingly high. In sporty use, it is annoying that the performance drops significantly at very high pedalling frequencies. Forestal sees the high support levels more as an emergency nail for short key sections than as a continuous mode. We agree with this appeal. Because if you use the full power of the motor continuously, the battery will be drained in no time. In addition, the housing gets very hot and the power is reduced.
Conclusion on the Forestal F60-S1/Bafang:
Plenty of power in a small, lightweight package. The F60-S1 motor delivers a striking e-bike feeling, but is unfortunately quite loud and a little uncouth. The battery runs out quickly.
- Weight (motor / system)¹: 2.03 kg / 3.93 kg
- Battery sizes: 360 Wh (1.9 kg)¹
- Range extender: 250 Wh
- Torque²: 79 Nm
- Peak power²: 386 W
- Power: 5.5 out of 6 points
- High cadence pull-through: 2.5 out of 6 points
- Engine sound: 2.5 out of 6 points
Orbea EP8 RS/Shimano
The software comes from Orbea, but the hardware of the EP8 RS motor is identical to the classic Shimano EP8. So it's no wonder that it can't keep up with the competition in terms of weight. On the other hand, with its decent power, powerful torque and large battery, the RS can almost keep up with classic e-MTB motors. The EP8 RS drive delivers its full power in the basic Turbo mode setup even with low rider input. As a result, the motor feels even more powerful in practice than the laboratory values would suggest. At very high cadences, the EP8 runs out of breath, which takes away its liveliness. The transmission rattles noticeably when rolling over obstacles.
Conclusion on the Orbea EP8 RS/Shimano:
Stable, powerful, long range - these are the strengths of the EP8 RS motor. The Shimano unit tuned by Orbea thus closes the gap between minimalist light drives and the power class. It is remarkable that Orbea builds such lightweight E-MTBs with this concept.
- Weight (motor / system)¹: 2.65 kg /5.43 kg
- Battery sizes: 360 Wh (2.78 kg)¹ / 540 Wh
- Range extender: 250 Wh
- Torque²: 56 Nm
- Power peak²: 339 W
- Power: 5 out of 6 points
- High cadence pull-through: 4 out of 6 points
- Engine sound: 3.5 out of 6 points
Specialised SL 1.2
Visually, the new light motor from Specialized has hardly changed, but technically a lot has happened to the SL 1.2. The e-bike motor has noticeably and measurably increased in power and torque, but not in weight and dimensions. Compared to the more powerful light candidates, however, the Specialized SL 1.2 is also a rather discreet supporter. There is no shuttle mode for lazy pedallers. On the other hand, the ride feel is smooth and the power is excellently modulated. The Specialized motor also stands out with its outstanding efficiency. The volume of the motor was a major point of criticism on the SL 1.1, and Specialized has clearly made improvements here too. However, the drive unit remains clearly audible. This puts it in the good midfield of the Light class.
Conclusion on the Specialized SL 1.2:
Light, efficient and smooth: The SL 1.2 is a discreet and unobtrusive light drive. Its strengths lie in efficiency and riding feel, rather than maximum performance and whisper-quiet operation. The display and controls are excellent!
- Weight (motor / system)¹: 1.91 kg / 373 kg
- Battery sizes: 320 Wh (1.82 kg)¹
- Range extender: 160 Wh
- Torque²: 50 Nm
- Peak power²: 278 W
- Power: 3.5 out of 6 points
- High cadence pull-through: 4.5 out of 6 points
- Engine sound: 4.5 out of 6 points
TQ HPR 50
Although we have not yet been able to test the TQ HPR 50 on the laboratory test bench, we know the drive very well. The TQ is the most compact drive in the Light class. In practice, its natural and discreet character is particularly impressive. The direct engagement of the freewheel creates a rich and high-quality starting feeling. The drive noise is particularly quiet and unobtrusive. In addition, the HPR 50 motor engages more smoothly than any other drive. The riding experience is therefore far removed from the classic e-bike thrust. This is also due to its moderate power, which is roughly on a par with the Specialized SL 1.2. One negative outlier is the stability of the small Rundling. It reacts to continuous full throttle operation with the most significant reduction in power and a high housing temperature.
Conclusion on the TQ HPR 50:
Benchmark in terms of volume, weight and ride feel - this makes the HPR 50 the most unobtrusive motor in the field. Perfect for anyone who wants to stay as close to the MTB as possible.
- Weight (motor / system)¹: 1.89 kg / 3.74 kg
- Battery sizes: 360 Wh (1.85 kg)¹, 250 Wh
- Range extender: 160 Wh
- Torque²: not measured
- Power peak²: not measured
- Power: 3.5 out of 6 points
- High cadence pull-through: 4.5 out of 6 points
- Engine sound: 6 out of 6 points
¹Determined on the test benches in the EMTB test laboratory.
²Manufacturer information
Determined in the PT Labs test laboratory. Roller dynamometer with performance test on the rear tyre.
The evaluation is based on the subjective impressions of the testers and the results of the laboratory measurements.
Josh Welz
Editor-in-Chief
