Lightweight mid-drive motors are a relatively new idea, first made popular on electric mountain bikes when brands were seeking something less bulky but still powerful enough to be ridden off-road. Nowadays, you don’t just find them on eMTBs; you’re likely to see them on electric gravel bikes and even some urban e-bikes. So what exactly are the benefits and how do the various options compare?
Lightweight mid-drives are a little less powerful than 'full fat' mid-motors, typically offering between 50Nm and 60Nm of torque - but crucially they only tend to weigh around 2kg (not including the battery).
If you’re after something that’s capable off-road but doesn’t weigh a ton, then an eMTB with one of the lightweight motors we’re dissecting (not literally) in this guide is a good starting point. You’re probably looking at spending a few thousand pounds on an eMTB, but possibly a bit less on an urban option.
Lightweight mid-motors typically come with smaller batteries to keep the weight down, so the range isn’t always as impressive. However, that reduction in weight is a fair trade-off for many.
You could of course go lighter still by running a hub motor. However, the big benefit of a mid-motor is that because of where it's positioned it can take advantage of your bike's gears. This means more torque when setting off from a standing start or riding up a steep climb and also greater efficiency at those slower speeds. If you want to learn more about the differences between hub and mid-drive motors, give our article on exactly that a read.
We’ll go through some of the most popular lightweight e-bike mid-drive motors in this guide so you can make an informed decision about your next e-bike.
Lightweight mid-drive motors
Battling it out – the specs
Bosch Performance Line SX
The Bosch Performance Line SX (often shortened to just Bosch SX) is the newest motor in this guide, having being released in 2023. It was adopted pretty quickly by some of the big eMTB brands, like Whyte, but it’s also starting to appear on some urban and gravel options from brands like Canyon and Cube.
It offers 600W of maximum power, with 55Nm of torque. It also utilises something called ‘sprint mode’ which works off of a rider’s cadence. The higher the cadence (to a limit), the more powerful and responsive the motor is. It weighs around 2kg, and usually comes with a 400Wh battery.
Fazua Ride 60
Fazua’s Ride 60 is the brand’s most powerful motor, but because of its compact nature and light weight, it’s still classed as a ‘lightweight’ mid-drive. It puts out 60Nm of torque, and up to 450W peak power in Boost mode. It’s even lighter than the Bosch SX motor, at just 1.96kg.
It’s popular with lightweight electric mountain bikes from brands like YT and Salsa, and even some gravel and urban bikes like the Canyon Roadlite:ON. It also comes with a reasonable battery considering its light weight, and Fazua claims it offers a range of up to 86 miles on one charge in favourable conditions.
Specialized SL 1.2
As you’ll probably have guessed by the name, the Specialized SL 1.2 motor is only available on Specialized branded e-bikes. SL stands for ‘super light’, and Specialized says its aim with the SL motors is to create something that feels natural to ride. So it’s not going to have the biggest power output (and it doesn’t, at just 320W max), but it will give you that edge and bridges the gap between an unassisted and a full-fat e-bike.
You’re likely to find the SL 1.2 motor on some of the Turbo Levo electric mountain bikes, while the urban bikes with the SL title are generally still on the older model, the SL 1.1. It’s designed to be seriously quiet, and Specialized claims it can offer a range of up to 34 miles from the internal 320Wh battery.
TQ HPR-50
The TQ HPR-50 is the lightest in this guide, at just 1.85kg for the motor unit. It’s also incredibly quiet and efficient. Fitting into a compact space, it’s popular on e-bikes that don’t necessarily want to look like e-bikes. Think the Trek Fuel EXe, for example.
It does lack some top-end power compared to the others, with just 300W maximum. But with just 50Nm torque you can’t expect miracles. TQ doesn’t state an estimated range with their 360Wh battery, but you can buy a range extender if that doesn’t feel like it’s enough.
The stats
Motor quality
| Bosch Performance Line SX | |
| Fazua Ride 60 | |
| Specialized SL 1.2 | |
| TQ HPR-50 |
It’s difficult to definitively rank the motors for quality, but Bosch do have the biggest network of dealers and people who can repair their products if anything were to happen. The TQ motor isn’t widely available on lots of bikes just yet, and the Specialized motor is just on Specialized bikes.
Motor weight
| Bosch Performance Line SX | 2kg | |
| Fazua Ride 60 | 1.96kg | |
| Specialized SL 1.2 | 1.95kg | |
| TQ HPR-50 | 1.85kg |
This one is pretty self-explanatory. The TQ is the lightest by 100g, which in the grand scheme of things, sure, maybe won’t make much of a difference, but if you’re a weight weenie, then it matters.
Motor power and torque
| Bosch Performance Line SX | 600W max power, 55Nm torque | |
| Fazua Ride 60 | 450W max power, 60Nm torque | |
| Specialized SL 1.2 | 320W max power, 50Nm torque | |
| TQ HPR-50 | 300W max power, 50Nm torque |
It's worth pointing out that these figures are the manufacturer's claimed numbers. Unfortunately we don't have any fancy testing equipment to check the validity of these claims, but we've tested enough e-bikes to know when brands might be being a bit generous with their numbers.
The Bosch and Fazua motors come out on top here thanks to their torque ratings - both claimed and from what we've experienced when riding SX equipped bikes. Interestingly, although the Fazua offers 60Nm of torque it doesn’t claim the highest maximum power. In our experience, the SX motor works better when you pedal faster, whereas the Ride 60 you can get away with using a slightly lower cadence to get the most out of the motor.
The TQ and Specialized are both still good mid-drives, but their strengths lie in ride quality and how quiet the motor is when operating rather than sheer power.
Motor/battery range
| Bosch Performance Line SX | 400Wh battery, roughly 40 miles of range in Auto mode | |
| Fazua Ride 60 | 432Wh battery, up to 86 miles | |
| Specialized SL 1.2 | 320Wh battery, up to 34 miles | |
| TQ HPR-50 | 360Wh battery |
When it comes to e-bikes, claims about range should always be taken with a grain of salt. There are so many factors at play that it’s difficult to say with certainty how many miles you can expect to get out of a single battery charge. It depends where you’re riding, what sort of terrain, which mode(s) you use and more.
The Fazua’s claims out-do the rest, even though that is with the biggest battery out of all them. We're not sure we've got that many miles out of a single charge when using the Ride 60 on an eMTB. From past experience we'd suggest 86 miles is optimistic - especially if you want to take advantage of the higher power assist levels.
We've given the TQ a 6/10 rating here just because when we've tried the system on a few different bikes, the battery range has always been less than we'd anticipated. TQ don't explicity give a range estimate, but given it's a bigger battery than the Specialized we'd expect similar results. Unfortunately, in our experience (and it may be different for other riders), that hasn't been the case.
Overall
| Bosch Performance Line SX | |
| Fazua Ride 60 | |
| Specialized SL 1.2 | |
| TQ HPR-50 |
It's quite difficult to definitively tell you which lightweight motor is 'the best', as they all offer different experiences. And, they're aimed at different audiences. If you're a Specialized bike lover, for example, it's no good reading about the Fazua or Bosch because they simply don't offer those options. Likewise, if you want something with a big dealer network and lots of bikes to choose from, don't go for the TQ. It's not a bad motor, but it's not widely adopted just yet.
After riding all these myself, my personal favourites are the Bosch and Fazua. The TQ is exceptionally quiet, and for most people will be enough of a boost, but for me it just lacks that top-end power I want for trail riding.
The Fazua works well for my style of riding, and doesn't require 100RPM to get the most out of it. It's easy to remove the battery for charging off-the-bike, and it offers the best range out of all of the options.
The Bosch is extremely good, too. The smoothness of the motor is second to none, and it's slowly being adopted by more and more bike brands after its launch last year. Essentially, you can't go wrong with any of these motors, but hopefully this guide has given you a bit more of an idea of each one's strengths and weaknesses.
