Electric Bike Mid Drive Motor Comparison

Court

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Hi guys! I'm moving some content off of the main site and into the most relevant categories of the forum. This post was originally made on January 21st 2017:

Mid drive motors are becoming more popular on electric bicycles because they offer certain strengths over traditional in-wheel hub motors. These include:
  • Improved frame balance front to rear and reduced frame flex
  • The ability to leverage a larger cassette, internally geared hub or continuously variable transmission for optimizing RPM and efficiency
  • Reduced unsprung weight (if the platform in question is a full suspension design)
  • Easier maintenance for the drivetrain and wheels (as well as less wiring across the frame)
This last two benefits are key for off-road riding where trail maintenance and transporting the bike become a factor. I love mid-drive or centerdrive motors but want to acknowledge that they aren’t perfect for every situation… they do have some limitations and drawbacks worth considering and these include:
  • Louder operation because they tend to be geared, they tend to produce the most noise in lower gears when the drive unit is spinning at higher RPM
  • Increased wear on the chain or belt, sprocket teeth and derailleur because the motor is adding force to the drivetrain, often doubling and even tripling your own pedal input! Some mid-drive ebike systems do not offer shift detection to make the motor “ease off” at critical moments when changing gears and this further stresses components
  • More active shifting and gear changing is required by the rider in order to start the bike, climb efficiently and reach maximum speeds due to limited RPM output at a wider range of operation vs. hub motors which connect directly to the wheel and don’t interface with gears
With this guide my intention is to offer a qualitative overview of the different brands of middrive ebike motors I’ve tested as of 2016 along with quantitative supporting points and specifications. Technology is evolving rapidly in the e-bike space and parts of this guide may become outdated so feel free to chime in using the comments at the end and I’ll make updates as needed. I’m not explicitly ranking the motors here but am starting out with some of the more popular, higher quality offerings. Bosch and Yamaha are two systems that get compared a lot and I’ve created a video with each of their stats and ride tests below to help demonstrate their differences:


Bosch Centerdrive
Bosch has been an innovator and leader in the mid drive motor space, both in Europe and the US, producing some of the most powerful and responsive systems I’ve tested. Companies that use it include Haibike, Felt, Trek, Easy Motion, Cube and others. The Bosch motor uses a smaller 16 tooth or 18 tooth chainring sprocket that spins faster than competing products (close to a 2 to 1 ratio) and is designed by each manufacturer… Some include metal chain guides (Haibike), plastic chain guards (Felt), narrow wide teeth and sprocket equalizing systems (Haibike) for their full suspension electric mountain bikes to raise the chain above the right chain stay, clear debris like mud and reduce kickback as the orientation of the rear cassette changes. There are several versions of this motor with output ranging from 15.5 mph (25 km/h) common in Europe to 20 mph (32 km/h) being the most common in the US and 28 mph (45 km/h) being a specialty motor available on some US models and requiring licensing in Europe. The Bosch electric drive system uses an advanced pedal assist system that listens for pedal torque, pedal speed and rear wheel speed to deliver near-instant motor control (it measures these signals ~1,000 per second). It also delivers a software-driven shift detection feature meant to reduce wear on chains and sprockets. Even with this system, some users have reported more frequent chain breaks and derailleur replacement with thousands of miles of use. The Bosch system does not require brake lever inhibitors because it turns on and off so quickly and I love that it seems to deliver a wide range of RPM speeds allowing it to propel riders to peak speeds in mid level gears, not just the highest gear. One area where Yamaha excels is that it has “Zero Cadence” starts while Bosch will only start once you reach 20 RPM (which is still very responsive). The complaints I have for Bosch include that their motor tends to be louder, producing a high pitched whine as it spins much faster than competing offerings and that it is not available with throttle mode. One of my favorite ways to ride is in a lower level of assist for efficiency and exercise with momentary bursts of throttle to climb, pass riders or get started from zero on mid-drive systems that do offer throttles… Not only does the system lack a normal throttle mode, Bosch has disabled walk mode in the USA for some reason and that’s confusing and frustrating because the button is still there. I have only seen the Bosch system with a single chainring at the front while some competing offerings like Brose and Yamaha are now offering two sprockets for a greater number of gear choices. With Bosch the bicycle manufacturer may choose from 16T, 18T or 20T chainrings and some opt for narrow wide teeth to reduce chain slip for off-road use. The Bosch drive system also costs more and weighs a bit more at ~8.8 lbs (4 kg). I want to call out the removable Intuvia display panel that features an integrated USB charging port for portable electronics. In Europe an even fancier display panel called the Nyon was released which had some early complaints around software bugginess and certainly adds some cost to the bike, it is not known when or if this will reach the US. The chargers I have tested weigh 1.7 lbs and offer 4 Amp power output for relatively fast charging Below are stat charts I’ve created with more details for each version of the Bosch electric bike drive system:

Bosch Gen 1 ( 2012 / 2013 / 2014 ) Power Range (Watts)250 wMax. Torque (Newton meters)50 NmMotor WeightBattery Capacity (Watt hours)(36 v 8.2 ah) 295.2 whBattery Weight5.4 lb (2.45 kg)Shift DetectionSupport LevelsEco: 50% 1-3, Tour: 120% 1-3, Sport: 190% 1-3, Turbo: 275% 1-3Max. Speed15.5 mph (25 km/h)

Bosch Gen 2 / 3 Active Line ( 2013 / 2014 / 2015 / 2016 ) Power Range (Watts)250 w – 350 wMax. Torque (Newton meters)60 NmMotor Weight8.8 lb (4 kg)Battery Capacity (Watt hours)(36 v 11 ah) 396 whBattery Weight5.3 lb (2.4 kg)Shift DetectionYes, (Derailleur Only)Support LevelsEco: 50%, Tour: 120%, Sport: 190%, Turbo: 275%Max. Speed20 mph (32 km/h) in USA, 15.5 mph (25 km/h) in Europe

Bosch Gen 2 / 3 Performance Line Cruise ( 2014 / 2015 / 2016 ) Power Range (Watts)250 w – 350 wMax. Torque (Newton meters)60 NmMotor Weight8.8 lb (4 kg)Battery Capacity (Watt hours)(36 v 11 ah) 396 whBattery Weight5.3 lb (2.4 kg)Shift DetectionYes, (Derailleur Only)Support LevelsEco: 50%, Tour: 120%, Sport: 190%, Turbo: 275%Max. Speed20 mph (32 km/h) in USA, 15.5 mph (25 km/h) in Europe

Bosch Gen 3 Performance Line CX (High Torque) ( 2015 / 2016 ) Power Range (Watts)250 w – 350 wMax. Torque (Newton meters)75 NmMotor Weight8.8 lb (4 kg)Battery Capacity (Watt hours)(36 v 11 ah) 396 whBattery Weight5.3 lb (2.4 kg)Shift DetectionYes, (Derailleur Only)Support LevelsEco: 50%, Tour: 120%, Sport: 210%, Turbo: 300%Max. Speed20 mph (32 km/h) in USA, 15.5 mph (25 km/h) in Europe

Bosch Gen 3 Performance Line Speed ( 2015 / 2016 ) Power Range (Watts)250 w – 350 wMax. Torque (Newton meters)60 NmMotor Weight8.8 lb (4 kg)Battery Capacity (Watt hours)(36 v 11 ah) 396 whBattery Weight5.3 lb (2.4 kg)Shift DetectionYes, (Derailleur Only)Support LevelsEco: 50%, Tour: 120%, Sport: 190%, Turbo: 275%Max. Speed28 mph (45 km/h) in USA and Europe

This first photo album shows the Bosch Gen 1 drive system with the smaller 8.2 amp hour battery pack and HMI display panel that had three levels for each of the four assist settings (eco, tour, sport, turbo) that we still see on later displays like Intuvia and Nyon (which dropped the extra three levels). Note that the display panel stands alone with integrated buttons only vs. a remote button pad and that it is not center mounted.

bosch-gen-1-ebike-motor-right.jpeg bosch-gen-1-ebike-motor-left.jpeg bosch-gen-1-ebike-motor-bottom.jpeg bosch-gen-1-hmi-display-console.jpeg bosch-gen-1-ebike-battery-pack.jpeg

This second album shows the 2014 / 2015 Bosch Gen 2 Centerdrive that had a larger plastic outer casing and is mounted horizontally. Bosch has explained that it has a 38% larger visual footprint than the 2016 Gen 3 Centerdrive which may be mounted at an angle, mechanically they are much the same.

bosch-centerdrive-performance-cruise-gen-2-right.jpeg bosch-centerdrive-performance-cruise-gen-2-left.jpeg bosch-centerdrive-performance-cruise-gen-2-bottom.jpeg bosch-centerdrive-performance-cruise-gen-2-intuvia-display-panel.jpeg bosch-centerdrive-performance-cruise-gen-2-button-pad.jpeg bosch-ebike-mid-mount-battery.jpeg bosch-ebike-rear-rack-battery.jpeg bosch-centerdrive-front.jpeg bosch-centerdrive-back.jpeg bosch-centerdrive-front-side.jpeg

This third album shows the 2015 /2016 Bosch Gen 3 Performance Line which is tipped up, surrounded with curved matching plastic instead of a flatter all-black case and delivers more torque or higher top speeds (for the CX and High Speed version respectively). Not all Gen 3 batteries will be inset into the frame as we see with the Haibike and not all will have a sprocket equalizing system to lift the chain or narrow wide teeth as seen here.

bosch-gen-3-ebike-performance-line-cx-motor-left.jpeg bosch-gen-3-ebike-performance-line-cx-motor-right.jpeg bosch-gen-3-ebike-performance-line-cx-motor-bottom.jpeg bosch-gen-3-ebike-performance-line-button-ad.jpeg bosch-gen-3-ebike-intuvia-display.jpeg bosch-gen-3-ebike-powerpack-400-battery.jpeg

Bafang BBS02
The standard 8Fun BBS02 kit manufactured by Bafang is a decent mid-drive motor available in a range of sizes from 350 watts to 1,000 watts. My personal favorites are the 500 and 750 watt systems because they comply with federal regulations in the US but still offer plenty of power and potentially even higher speeds like a speed pedelec. I want to call out E-RAD because they offer physical shift sensing, a range of bottom bracket sizes and good customer support and warranty coverage. Most of the other BBS02 motors you’ll find on eBay or small online shops do not have the shift sensing support and are not available in different bottom bracket widths so you won’t be able to use them with fat bikes, some full suspension models and brands like Trek and Giant. I believe Luna Cycles may offer a customized BBS02 unit and a shift sensor accessory but have not tested their equipment. Frankly, the stock BBS02 would be much further down my list here without E-RAD. What I like about the motor is that it offers both pedal assist (more basic cadence sensing albeit) as well as throttle operation (twist or trigger) so there are no compromises in terms of ride style. You’ll definitely want brake levers with motor inhibitors with this system because the motor doesn’t stop as quickly as the Bosch Centerdrive and some others on this list. What you do get is lots of of power, relatively quiet operation and with the unlocked kits you can also go much faster (beyond 30 mph). Please, just be careful if you do unlock the motor and consider limiting top speed to ~28 mph as this will classify you as a speed pedelec if the throttle is unused. Anything above 20 mph with the throttle should only be used on private property or national forest where other motorized vehicles are allowed. I have only seen this kit built up with a single chainring to date but it may be possible to modify it to work with two sprockets and I believe there is a Tern + Xtracycle + E-RAD collaboration in the works that may deliver this. While E-RAD does offer some pre-built electric bikes, most customers seem to purchase just the drive system in order to install it on existing frames themselves which could require additional tools and effort. Many customers also prefer to swap out the stock chainring for a RaceFace NW (narrow, wide tooth) sprocket with fewer teeth and better chain tracking for off-road and e-mountain bike use. The smaller sprocket will allow the motor to spin faster and climb better much like the Bosch system described above. Depending on the motor size you get, the weight will change but expect the 350 watt to be around 7 lbs, 750 watt to be 7.7 lbs and the 1000 watt to be around 11.6 lbs.

8fun-bafang-bbs02-mid-drive-left.jpeg 8fun-bafang-bbs02-mid-drive-right.jpeg 8fun-bafang-bbs02-mid-drive-bottom.jpeg 8fun-bafang-bbs02-mid-drive-button-pad.jpeg 8fun-bafang-bbs02-mid-drive-lcd-display-panel.jpeg bbs02-ebike-shark-battery.jpeg bbs02-ebike-dolphin-battery.jpeg

Impulse
The Impulse drive system is one of the softer, quieter mid-drive motor systems I’ve tested and as a result it is not as immediately impressive as Bosch, Yamaha and some of the others. It’s relatively light weight at 8.37 lbs (3.8 kg) and commonly found on Kalkhoff and Focus electric bikes and comes in a smaller 250 watt size most frequently. As of 2015 in the US a 350 watt version was introduced for their speed pedelec bikes that can reach ~28 mph. The Impulse 2.0 drive system uses a single, more standard sized chainring and relies on an advanced cadence sensor to measure pedal torque and wheel speed to activate and de-activate. Just like Bosch and Yamaha it does not rely on integrated brake-lever motor inhibitor switches because it’s very responsive. It does however, offer mechanical shift sensing that is some of the best in the business. It actually measures the wires changing position as you shift gears vs. just using software to guess like Bosch. I was able to clearly distinguish when the motor stopped during shifting and it leaves a longer gap in time by default. If you’re into performance however, some of their more advanced display systems will let you alter the timing for shift sensing. I enjoy the 350 watt Impulse speed system the most but appreciate the light weight and quieter operation of the 250 watt for urban style electric bikes. It’s definitely designed for more active riding and required more effort when pedaling than some of the others. Unlike the BBS02 from E-RAD which relies on a cadence sensor that simply senses crank arm forward movement, this one relies more on pedal torque so you have to engage and push actively to get the motor to help out. This system does not seem to be available with throttles and complies more closely with EU regulations than some of the others which are adjusted for the US market to offer more power. That said, I was told that it offers 70 Newton meters of torque which is 10 more than the standard Bosch drive system (keep in mind, the CX from Bosch offers 75 and is used on Haibike models). My experience is that Bosch is still more satisfying and “active feeling” but louder and more zippy than Impulse so depending on your ride style this could be a high quality option. The chainring side of the motor can be difficult to photograph because most ebikes that use the system come with full coverage chain guards, so here’s the opposite side for reference on a Kalkhoff model:

impulse-2-mid-drive-20-low-speed-left.jpeg impulse-2-mid-drive-20-low-speed-right.jpeg impulse-2-mid-drive-20-low-speed-bottom.jpeg impulse-2-mid-drive-20-low-speed-backlit-button-pad.jpeg impulse-2-small-display.jpeg impulse-2-seat-tube-battery-pack.jpeg

The images below show the high speed version of the Impulse 2.0 and in this case the motor is flipped and protected by a louvered push guard on the downtube and base.

impulse-2-mid-drive-high-speed-left.jpeg impulse-2-mid-drive-high-speed-right.jpeg impulse-2-mid-drive-high-speed-bottom.jpeg impulse-2-mid-drive-high-speed-buttons.jpeg impulse-2-mid-drive-large-display.jpeg impulse-2-mid-drive-high-speed-battery-pack.jpeg

Yamaha
Yamaha is the newest entrant on this list, joining the electric bike space in 2016 in the US. Their system is less complex but costs a whole lot less and works pretty well… as long as you don’t mind huge charging bricks. It uses larger more standard sized chainrings and yes, rings plural! You can have more gears with one of their systems and it’s well suited to off-road use given the higher power rating of 500 watts and 80 Newton meters of torque. Lots of people have wondered how it compares with the Bosch system because Haibike offers both on their models and I’d say it’s generally less responsive and more on/off feeling based on pedal torque alone vs. smooth. One big thing that’s missing here in my mind is shift sensing and given the higher power output I wonder what kind of chain, sprocket and derailleur wear owners will encounter with long term use? For the time being, Yamaha is just another mid-drive choice that’s similar to the others for riding around the city but offers higher torque for climbing and the “Zero Cadence” feature which is nice for off-road climbing from rest. One thing that bugged me about it is that the motor seems to have a limited speed range and so, when you’re pedaling in a lower gear (even while using the High mode of assist) the top speed drops and you can’t hit 20 mph as easily. In order to actually hit ~20 mph I had to be in the highest assist level and the highest gear and this really slowed my cadence and put pressure on my knees and muscles. I prefer to spin quickly and have sensitive knees so I kept shifting down but would notice a steep drop off in power and speed as a result. I believe the system relies heavily on torque sensing and may do this to increase range but it’s very frustrating to be riding at high speed towards a hill while mountain biking, shift down to increase cadence for climbing and feel the motor support completely drop out… only to kick back in after you’ve lost 3 to 5 mph ultimately slowing your pedal cadence down again and straining your knees. While testing this system off-road for this guide I found myself shifting all the way down to the lowest gear to reduce my own effort but ended up going very slow as a result. I’d prefer to rush up hills if I could maintain momentum and I just don’t feel like the motor does this if you shift down. If I’m in the highest assist, I want help at 20 mph regardless of the gear I’m in (or at least the top several gears), not just the absolute highest gear. I appreciate that Yamaha has been able to reduce the price of mid-drive e-bikes with their drive system and also enjoyed both of their display panels (a more basic LED console is used for the cheapest bikes) and like how sleek their battery packs look and that they can be charged on and off the frame.

Yamaha Electric Bike System ( 2015 / 2016 ) Power Range (Watts)250 w – 500 wMax. Torque (Newton meters)80 NmMotor Weight7.6 lb (3.45 kg)Battery Capacity (Watt hours)(36 v 11 ah) 396 whBattery Weight6.5 lb (2.95 kg)Shift DetectionNoSupport LevelsEco+: 50%, Eco: 100%, Std: 180%, High: 280%Max. Speed20 mph (32 km/h) in USA, 15.5 mph (25 km/h) in Europe

yamaha-mid-drive-ebike-motor-left.jpeg yamaha-mid-drive-ebike-motor-right.jpeg yamaha-mid-drive-ebike-motor-bottom.jpeg yamaha-mid-drive-ebike-button-pad.jpeg yamaha-mid-drive-ebike-display-panel.jpeg yamaha-mid-drive-ebike-battery.jpeg yamaha-electric-bike-motor-front.jpeg yamaha-electric-bike-motor-back.jpeg yamaha-electric-bike-motor-side.jpeg

Shimano STEPS
Shimano entered the US electric bike space in 2015 and delivers more than just a mid-drive motor, they also pair the system with electronic shift sensing in some cases (the Raleigh Misceo iE for example). Some Trek electric bikes and IZIPand Raleigh models also use the Shimano drive system. Their motor is quieter and less powerful than Bosch, Yamaha and some of the others but offers a nice blend of cadence sensing and torque sensing assist. I love how compact and light weight it is at just ~7.05 lbs as well as its responsiveness. Even the battery packs tend to be light at ~6 lbs depending on whether you get the downtube mount or rear rack design. It uses an advance pedal assist system that measures pedal torque, cadence and wheel speed so it doesn’t require brake lever inhibitors. Much like the Impulse 2.0 system mentioned above, it relies more on torque so you’ll have to pedal actively to get the most power, up to 50 Nm of torque with low 50%, medium 100% and high 200% relative feedback. It opts for a more standard sized chainrings and as of this guide is only available in the 250 watt nominal size (with peak out put closer to 500 watts). Just like Bosch, it relies on software for shift sensing but this feature is only available with the Di2 electronic shifting mentioned earlier and not on traditional mechanical derailleurs or internally geared hubs. This is a big reason why I’ve ranked it below the Impulse system, shifting gears while pedaling with assist can stress the chain and derailleur, produce chunking mashing sounds. Unlike some of the other systems that don’t ease off as you reduce pedaling pressure, the Shimano STePs motor seems more refined and won’t stress the gears as much if you are pedaling gently just before shifting. This is not a motor that offers higher speed ~28 mph operation nor is it available in different power configurations… you’ll mostly find it on neighborhood and city bikes. One other gripe I have about the system is that the 2015-2016 models featured battery packs that had to be removed from the frame in order to charge! All of the other batteries for motors listed above could be charged while left on the frame which reduced the chances of dropping and saves time. You also have to power the battery on for the display to activate vs. doing it all from the button pad up on the bars. I’m told that the next generation of Shimano batteries will let you charge on-frame so here’s to 2017! One neat feature I appreciate about their control pad interface is that it can be used on either the left or right bar (it’s actually the same physical design as their electronic shifter mechanism) and the display panel is removable for safer storage, you can even turn off the backlighting and beeping if you’d like by holding the up and down arrows simultaneously to enter the menu system.

shimano-ebike-motor-left.jpeg shimano-ebike-motor-right.jpeg shimano-ebike-motor-bottom.jpeg shimano-ebike-button-pad.jpeg shimano-ebike-lcd-display.jpeg shimano-ebike-mid-mount-battery.jpeg shimano-ebike-rear-rack-battery.jpeg

Brose
This is a newer motor to me but one that’s popping up on a lot of electric bikes including the Specialized Turbo Levo and Bulls models. It’s compact, powerful and fairly quiet because a belt drive is used inside verses gears on most of the others. It’s a great performer as a motor but in combination with cassettes, chains and even internally geared hubs it causes me concern because there does not appear to be any sort of shift sensing. I’ve heard more aweful bangs and mashing with this motor than all of the others listed above and while it does offer similar advanced pedal assist (speed, cadence and torque) it’s not instant and may require an adjustment in ride style to reduce strain on your chain, sprockets and derailleur. One thing I do appreciate about the system is how well integrated it and the accompanying battery pack can be. It seems a lot more flexible than the Bosch, Shimano, Yamaha and Impulse systems but may be more difficult to get replacement packs for. I saw two different battery configurations on the Bulls bikes alone and that costs more money to manufacture. Still, the integrated batteries look great and bring weight even lower on frames for improved balance. Generally speaking, this mid-drive motor and accompanying systems seem more custom and things like chain rings, guides and even control interfaces are varied across bikes which can look cool and be stealthy but increase price and may have an impact on usability and familiarity that shops have across different models.

specialized-s-works-turbo-levo-fsr-6fattie-brose-mid-drive-motor.jpeg

TranzX
This system is very similar to the BBS02 in that it feels more like a cadence sensor and sort of bangs to start vs. being so smooth (at least in the higher levels of assist). It’s more affordable than the others for a reason and while it does not require shift sensors, the larger more standard sized chainring spins down slower than some. I used to promote the benefits of throttle operation on this motor with some of the IZIP electric bikes but starting in 2016 a lot of them seemed to disappear as manufacturers pushed for throttle regulation in the US so they could import exact models from the EU to reduce costs. That didn’t happen because Pedego introduced a separate bill to keep throttles and now we see a lot of mid-drives without assist and nothing special to offer other than a low price point. TranzX motors may also be found on Raleigh and Diamondback ebikes. Unfortunately, I have heard from users and some dealers that the TranzX system is also susceptible to a complete unit failure if used for heavier loads and climbing. I’m not sure exactly what the issue is but it sounds unrepairable and complete units have had to be replaced in many situations (so it’s nice that the unit is often warrantied for a year by the bicycle manufacturer using it).

This first group of images shows the oldest TranzX motor I’ve encountered called the M07, it is still used today on many ebikes because of the high torque output it offers. Many of the newer models have upgraded firmware that improves performance and smoothness.

tranzx-m07-ebike-motor-left.jpeg tranzx-m07-ebike-motor-right.jpeg tranzx-m07-ebike-motor-bottom.jpeg tranzx-m07-ebike-motor-button-pad.jpeg tranzx-m07-ebike-motor-lcd-display.jpeg tranzx-m07-ebike-motor-battery-pack.jpeg tranzx-m07-ebike-motor.jpeg

This second group of images shows the TranzX M16 GTA motor which is slightly lower torque, a bit more smooth than the M07 and much more responsive. I see it on city oriented bikes vs. trail and off-road for the M07.

tranzx-m16gta-mid-drive-ebike-motor-left.jpeg tranzx-m16gta-mid-drive-ebike-motor-right.jpeg tranzx-m16gta-mid-drive-ebike-motor-bottom.jpeg tranzx-m16gta-mid-drive-ebike-motor-button-pad.jpeg tranzx-m16gta-mid-drive-ebike-motor-display-panel.jpeg tranzx-m16gta-mid-drive-ebike-motor-rear-rack-battery.jpeg tranzx-m16gta-mid-drive-ebike-motor.jpeg

This final group of images shows the newest TranzX M25 which is more compact and lighter weight than the M07 and M16 models. It offers good torque and is found on the higher end speed-pedelec urban bikes.

tranzx-m25gts-electric-bike-motor-left.jpeg tranzx-m25gts-electric-bike-motor-right.jpeg tranzx-m25gts-electric-bike-motor-bottom.jpeg tranzx-m25gts-electric-bike-motor-button-interface.jpeg tranzx-m25gts-electric-bike-motor-display-interface.jpeg tranzx-m25gts-electric-bike-motor-integrated-battery-pack.jpeg tranzx-m25gts-electric-bike-motor.jpeg

Other Mid Drives (EVELO, iGo, eProdigy, Optibike etc.)
I’m not sure what to call this canister style mid-drive these canister and smaller circular mid-motors. In my opinion this type of product is best suited to neighborhood and urban use because it has a more limited RPM range. This causes similar problems to the Yamaha system mentioned earlier where you literally cannot hit 20 mph unless you’re using the highest gear. One upside with this system however (at least on the note of max-speed) is that you don’t have to push very hard on the pedals because they almost always rely on cadence sensors. One other positive with these systems is that they often allow for throttle mode as well! So it comes down to one of these low-end systems that do not have shift sensing and really aren’t all that powerful or fast, besides the EVELO 500 watt version, or one of the BBS02 8Fun kits if you want a throttle. These generic motors aren’t especially quiet and do not appear to be easy to work on (possibly a full swap vs. maintenance?) The benefits of having a middrive are greatly diluted by these factors and this is the level where getting a basic internally geared hub motor starts to look pretty good, especially given their mostly on-road use.

2014-evelo-aurora-cadence-sensors.jpg eprodigy-whistler-350-watt-mid-drive.jpg

Most of the feedback in this guide comes from me testing demo bikes back to back to back… doing my best with qualitative observation to determine how each rides. I mixed in some stats and details from reviews and acknowledge that the systems are all changing year over year and that I may be incorrect in certain cases. Please chime in with your thoughts and experiences so this guide can be as accurate as possible. It is not sponsored or weighted by any particular brand and my goal is to be unbiased and objective. One other mid-drive system worth calling out here is the Optibike SIMBB found on one of their custom models. Optibike also delivers one of the lower end middrives on their Pioneer bikes and some super powerful ones on their R-Series but I left them out because they operate on throttle only and are not street legal given the higher power and top speeds. The SIMBB by comparison is completely sealed and includes the batteries inside! It’s powerful and responsive but did not include shift sensing at the time this guide was created.
 

Court

Administrator
Staff member
#2
Following are some of the original comments that were made on that post:

MARCO
Hello, I write from Italy and I would like to know if you have any information on the mid kit Sunstar SO3 Japanese production, which should be the first and original engine Befang.

COURT
Hi Marco! I’ll keep an eye out for the Sunstar motor you mentioned, so far I have not seen nor heard of the company or the motor itself, which bikes did you see it on or is it just a kit?

JOHN VERRILLI
Hi Court, If you had to choose between the Shamino and Bosch motors do you have a preference on the two bikes I mentioned on the Cannondale Kinneto and the Felt sport-e with the Bosch motor. Thanks, John

COURT
Hi John, my preference with the 2015 and 2016 models would be for Bosch but I hear there’s a new Shimano system coming soon (maybe for 2017 in the US?) so I can’t speak further until I try it. Bosch has long been a leader in the space and they seem to be some of the most thought out, durable and widely available ebike drive systems around. In terms of brands, I feel that Felt does a good job and having tested the Sport-E I’d say it’s a solid bike :)

MARCO
Here’s another ebike kit worth checking out.

COURT
Thanks Marco, have you test ridden this or known anyone who has? It looks similar to the Bafang BBS0 mid drive motors I have seen here in America.

HONG QUAN
Hey Court,
You should write about the new Bafang mid-drive system. I know there aren’t many bikes using it yet, but the MAX motor is a huge improvement over the prior generation BBS motors. Let me know if you want a test ride!
Cheers,
Hong

COURT
Hi Hong, I’d love to check it out more in-depth. My time in SoCal doing reviews is limited but I’ll be heading to Colorado soon… Do you guys have a demo unit you could send out so I could review your bikes and learn more about the MAX motor? Use the contact form here and let’s work something out :)

HONG QUAN
Hi Court,
We don’t have any demo units right now, just beta bikes in some customers hands. Are you coming up for the EBike Expo in Palo Alto? I have your number so we’ll be in touch next month when our production bikes arrive.

JACK
Hi Court, Fifty cycles, an English bike store has an article on their bike blog here comparing the Impulse and Bosch motors. On paper, it seems like the Impulse is the clear winner. The Impulse has greater torque, greater battery capacity and range-125 miles in eco mode, and 1100 charges on its battery compared to only 500 on the Bosch. I would be interested in reading your take on this debate. Thanks. Jack

COURT
Hi Jack, cool! I don’t have time to read the article right now because I’m traveling for reviews but I agree that the Impulse system (especially the high-speed version) is awesome! I still like the smaller sprocket and more powerful feel of the Bosch system compared to Impulse but can’t deny that their shift sensing is superior (and adjustable). The battery durability thing isn’t something I’ve been able to thoroughly test, though I have only heard great things about the longevity of Bosch packs. In the US, more people seem to have Bosch so far but as Impulse becomes more available (with Kalkhoff and Focus expanding) that may change and I’d welcome more input :)

RONI
Hello. I’m from Israel, sorry for bad english. I have a KTM bike, with Panasonic hub Motor. My trip is an urban area with hills, and the system of Panasonic a little weak. I would like to buy a bike of Haibike.
  1. I am debating between: Yamaha or Bosch. In My area, no service these systems, so I need a reliable system. Which system do you recommend?
  2. Panasonic’s system has Pedaling resistance When engine stops working, above the 25 mph speed, and when the battery runs out, so also is it in Yamaha and Bosch?
Thanks Roni

COURT
Hi Roni, you may get less pedaling resistance from Yamaha because there is no conversion to match the sprocket size to cadence (notice how Bosch uses a slightly smaller sprocket in the front, it spins at a 2:1 ratio for what you pedal at). It’s not much extra resistance but there is some. You will also save some money with the Yamaha and that could be useful if you have to replace the system at some point given that they are not carried where you live. Yamaha has not been in the USA long enough for me to comment on durability but my guess is that it’s very good similar to Bosch. All ebike systems experience some slowdown as you ride faster because of air resistance and just the weight of the battery and motor vs. pedaling on a normal bike. I hope my answer helped you a bit and I wish you luck! Please let me know what you choose and how you like it so we can help others in a similar spot!

RONI
Hi Court, Thanks for the quick and detailed reply. I think the Yamaha and Bosch have magnetic resistance of the motor, I read the Brose has a detachment of the motor when the speed reaches 25 mph. (Speed limit), to prevent the magnetic resistance. Thanks Roni

COURT
Hi Roni, all of the Bosch powered ebikes I’ve tested have a traditional freewheel in the rear so you can definitely coast past 20 mph without any interference. I haven’t pedaled past 25 mph enough to comment on how the gearing responds in the centerdrive but my guess is that it works fine. I don’t think there’s much cogging since it’s geared but cannot say for sure. It sounds like you’re set on Yamaha or Brose, both systems work pretty well in my experience and I’ll be reviewing the Turbo Levo Comp and Expert soon which use Brose so keep an eye out :)

DAN NISSENBAUM
Can you purchase the Bosch motor just as a kit and install it on any bike?

COURT
Hi Dan, unfortunately I do not think you can. Bosch is particular about finding bicycle manufacturers and partnering with them at the B2B level. They don’t sell direct and are very protective of even showing the inside of the motor… Plus, even if you could get the motor battery, display etc. you’d need a custom frame to install it on because the mounting configuration is very specific and proprietary. The best bet to get Bosch would be to purchase a more affordable pre-made bike from Cube, Haibike or Felt. The only mid-drive kits I see as aftermarket are the BBS02 from Bafang and I like the E-Rad versions best because the width of bottom bracket can be customized and they offer shift sensing like Bosch and Impulse :)

DAN NISSENBAUM
Thanks very much for the comments and insight. Here is why I asked: Do you have a sense of how to judge this motor kit arranged as an Indiegogo campaign? Dan

JACK TYLER
For those of you reading this thorough guide on mid-drive motors (Thanks, Court!) you might want to see an equally thorough demo of the display systems on the two most common systems: Yamaha & Bosch. A Utah ebike store – Blue Monkey – has done a nice job of producing those demos and the links are below. While Court covers these displays in each of his reviews, the close-ups and screen annotations used in these demos make things crystal clear. Enjoy! Yamaha Display and
Bosch Display overivews. -Jack

COURT
Awesome, great links Jack! Thanks for including those, I love the guys at Blue Monkey, they produce some cool videos including these display guides :D

JOHN
Hi, john in texas, i have a bafang 750 on a road bike and i love it. looking for off road mountain bike not sure to make one with the bafang or buy one all made like the hibike, then which one, bosch or yamaha?

COURT
Hi John, with both Bosch and Yamaha you’ll get a Class 1 ebike that’s allowed in more places because you have to pedal in order to make it go. Building your own might not look as nice (with cables and bolt-on battery) but you’ll get a throttle. It also probably won’t be as smooth and responsive as Bosch followed by Yamaha. My personal favorite is Bosch or the new Brose motor system. I don’t miss the throttle so much and like blending in and using the bike in more places. Keep in mind, the top speed is 20 mph for these commercial ebikes vs. building your own, you can get more power and go faster. It depends on the laws, how you want to use it and where you plan to go :)

MARIO
Hi Court, Could you tell me a bit more about the engine used in Stromer ST1 bikes, I haven’t seen them mentioned in the article?

COURT
Hi Mario, I believe they use a 500 watt gearless, direct drive TDCM motor which is similar to what you’d find on A2B or some of the Specialized Turbo bikes (not the LEVO, just their road bikes). Specialized actually uses a GoSwiss Drive but it’s still gearless, offers regen and is very powerful but possibly lighter than Stromer. All of these motors are known for being durable because there are no gears moving around inside. This is a very basic intro, hope it helps you find more information, feel free to ask about it in the forums as some people really like the motors and build their own conversion with them :)

JOSH
I suggest you also check out the MPF drive, reputed for being quiet. I cannot speak to their responsiveness, but plan to test drive one this weekend, on the Butchers and Bicycles Mk1-E.

COURT
Nice, I’d love to hear how it works for you! Appreciate the heads up Josh :)

TOM MILAN
I own a Giant Trance 1, 2016. At age 72, I’ve decided to get some power assist in order to keep up with my buddies. I can get pretty good deals on a Specialized Levo and on the Giant electric mtb. Being a frugal sort, I am also thinking about converting my Trance using a Sabang BBSHD 1,000 watt system. I ride about 30 off-road miles per week. What is a good choice for my needs? Thanks for your help and your insightful reports.

COURT
Hi Tom! There’s a lot to consider here including style. I prefer to buy purpose built ebikes just because the wires are integrated and you get a warranty. Kits are alright and E-Rad makes one of the best Bafang BBSHD motor variants (in different sizes and with shift sensing). Of the two stock bikes you mentioned I have only tried the Turbo Levo to date and I love how quiet and good looking it is… it totally blends in which is nice.

JOHN VERRILLI
How does the Shamino motor in the Cannondale Kinneto compare with the Bosch motor in the Felt Sport-e 95 for top end speed on a flat road. Which bike will go further under the same conditions. Thanks, John Verrilli

COURT
Hi John! It looks like the Cannondale Kinneto is using the Shimano mid-drive… I haven’t tested that specific bike but I did try the Raleigh Misceo earlier this year and I believe it uses the same drive system. From my experience the battery design was disappointing because it couldn’t be charged on the bike and the motor was alright. It worked well enough for urban riding on paved streets and such. Hope this helps!

JENE GALVIN
Court, I’ve owned an Easy Motion Neo Carbon, Felt Sporte and Izip e3 Peak, the last two currently. But I’m thinking of selling them if I can find a replacement that combines most of their combined features: 28MPH, battery life and weight. I’m looking at the Raleigh Redux ie, but I’m wondering if the 250 watt Brose motor has enough power. I live in the hill country of Northern Kentucky. Do you know much about the power of that smaller wattage motor? Thanks for all the great e bike info you provide to us enthusiasts.

COURT
Hi Jene, sounds like you’ve got lots of experience with ebikes! I really enjoy th eBrose motor and have found that both it and the 250 watt rated Bosch motor from Europe still perform well. I’m not super heavy and I enjoy pedaling along but even climbing in the mountains, these motors have done a good job. I can understand why you’d be excited about the Class 3 bikes to go a little faster. If you’ like the Raleigh Redux ie then I’d say go for it! I haven’t tested the latest version yet and am excited to hopefully later this year :)

THOMAS JASZEWSKI
One more low priced kit is the BEWO. Not very common but decently supported but weak compared to the eRad. After three years of kits, primarily mid drive BBSxx series, I’m looking forward to a purpose built bike. I didn’t mind all the wires and such at first, but have come to be frustrated with the mess they can be. Also the maintenance. Every so often I snag a wire on something. The only kits that excite me these days are the BMC and MAC gear drive hub motors and their increased ability to handle some hills.. But with the external controllers they are definitely not neat. One thing we seldom mention when selling kits are the real costs of upgrading a frame to electric. By the time the fenders, lighting, rack, and other upgrades are done one can easily have spent the cost of a frame with integrated wiring. It’s easy to spend $2500-$3000. There are quite a few very nice prebuilts for those dollars. The only reasons I can see for kits are, cost, there are some really cheap kits. Next is speed and there seems to be a large market of folks that want to exceed the braking capacity of their bikes. The BBSHD is a great kit but like several others here it’s best detuned in my opinion, but it’s being souped up to run at much higher speeds. For me an unfortunate direction.

COURT
Hey Thomas! I’m with you, the purpose built ebikes feel more complete and I like they way they look. It usually costs a bit more up front but they tend to hold up well over time and I’m less excited about tinkering these days with work and other busy life stuff. Interesting point about “braking ability”. When you start looking at mainstream speed pedelecs they often upgrade the brakes to hydraulic and some even go from 9 mm skewers to thru-axles and other DOT approved hardware. In Europe they are much more strict and you can see the safety features sort of trickle down to the US markets. I’d love to hear what bike you end up focusing on and eventually getting. Are you in the market for a trail bike or more of an urban commuter type thing? I really liked the Stromer ST1 Limited which has lights, fenders, a quiet motor, regenerative braking, a hidden battery with all of the wires internally routed and decent support. I believe they have been on sale lately with the launch of the ST1 X coming up.

ROSS MOORE
I can’t find a review of the bafang bbs02. Have you done one? please reply to my email address. Thank you.

COURT
Hi Ross, I have indeed reviewed that motor but listed it under 8Fun vs. Bafang (same company, Bafang sells direct as 8Fun) here’s the review.

GERRY
As I read through your mid drive motor comments i wonder if you still would put the Brose motor so far below the Bosch because the Brose does not have shift sensing. You seemed to speak well of the Bulls bikes using the Brose mid drive motor this year (2017). Also it sounds like the Impulse motor won’t be used any more, that group reportedly has gone only to Bosch.
Since i live 300 miles from any ebike stores what i buy has to have a long life system. So if I’m interested in a long life quality motor, is Bosch really the only choice?
Thanks Court.

COURT
Hi Gerry! My personal favorite is Bosch for the features and durability (all dealers speak well of it) but Yamaha is also very reliable and trusted… Brose is probably on a similar level but the battery packs are not standardized like most Bosch and Yamaha which makes them more expensive. They look great, the motor is quiet and seems very well engineered, I trust it because big brands like Specialized, Easy Motion and Bulls use it. I think you are safe with any of those, or even one of the Shimano motors (they are coming out with some new ones at Interbike this year). I hope this helps, now should be a good time to get a deal on a 2017 electric bike since the 2018 stuff is just around the corner :)

RON
I’m looking to get a recumbent trike, I’m thinking the Trekker from Trident since it folds and seems to be a good value. Have you any other recommendations? I really like the idea of having a portable trike if I’m jumping on public transportation or going up stairs. With that in mind, I’m undecided about installing a rear hub or mid drive motor on this trike. Trident installs a rear hub but I’ve read and I think you’ve interviewed someone who says mid drives are more efficient with mix terrains. I’m in California and I currently have a Day 6 Dream 7 bike and I’m struggling with these gradual slopes. Do you know of any shops who sell drive kits? Oh, and do I know have to concern myself with class drives?
Thank you!
Ron

COURT
Hi Ron, I believe Day 6 sells converted electric bikes, but you could try to install a kit on your own too, they use E-RAD which I have done some reviews for here. As for trikes, the mid-drive is not used as often because there are usually two rear wheels, so it would only turn one of the two and getting it to work with the chain and mount properly at the often unique bottom bracket could prove difficult. It’s something you could ask about in the EBR forums or maybe ask the guys at E-RAD about. I hope this helps! I’d love to hear what you end up doing :)

JEFF MUELLER
I think I’d like a bike that gives me features I see in the Bafang BBS02. I’d like to be able to pick a setting that gives me over 20mph… I like the throttle feature. Sounds like competitors have other inputs they measure in their motors but don’t allow users higher speeds and a throttle.

COURT
Yeah, I think you’ve got it right mostly. There are mid-drive motors from Bosch and Brose that can reach ~28 mph but none of the big names (Bosch, Yamaha, Shimano, Brose) have throttle options because they are focused on the larger European markets right now.

NOEL
Hi Court, thanks much for the reviews!! Just out curiosity for Performance Line of Bosch mid-drives, are there significant differences between the internals for the 20mph and 28mph models… or is it just the difference in the cutoff speeds?

COURT
Hi Noel! My understanding is that the hardware is very similar (possibly the same) between Performance Line Cruise and Performance Line Speed but if you go up to the CX, there might be more copper winding. I think a lot of the difference is in software settings :)

TOM
Hi Court, how would you judge this fat bike (components: battery, motor,..)? In your opinion is it well assembled? Many thanks, Tom

COURT
Hi Tom! I can’t really say, the details are not written in English and at first glance, none of the motor or battery hardware is stuff that I recognize. A big part of my own buying and rating decision has to do with warranty and customer support. If this is a trusted brand where you live, perhaps it could be a good fit. It does interest me to see a belt drive on a fat tire bike. I wonder how they hold up in snow, mud, etc. and whether you’d be riding on that sort of terrain? If you do buy it, I’d love to hear your feedback and maybe see some closeup pictures in the Other Ebike Brands Forum and perhaps I’ll get a chance to see and test this thing some day too ;)
 
#3
Hi Court,
Don't see Bofelli motor mid-drive reviewed here. I'm looking at the all go carbon by m2s. Its rated 350 w min and 700 max. I'm 160lb and 5' 8" . like the weight of the bike. I do 80% ride streets and have 2-4 miles in the directions I go that rise 1500 feet over 4 mile. Also some mild trails . Just want to feel confident I can get up those hills ok. I'm dealing with back and some cardiac issues. Don't mind peddling and pushing some but want to feel I'm going to get enough help. Any opinion? thanks!
 
#4
@Jack Laurie, here's some info from a post by M2S' owner, Eric Crews:

"The bike features the Bofeili mid-drive motor that is rated for 250 watts, although the watt meter on the bike consistently shows watt output of over 650 watts when put on the highest pedal assist speed. The digital display / speed controller has five levels of assist that more-or-less corresponds to watt output. For example, on level 3, the bike puts out between 250 - 350 watts of power to help the cyclist maintain a fast cadence. If you shift into a harder gear, the watt output increases until the cadence returns to a faster pace or speed increases."

This is the same style of crank shaft motor used by Evelo & E-Prodigy.

The M2S website rates it at Torque: 65 Newton Meters, which is good but may not be enough for your particular needs.
Also the M2S site indicates that the All-Go Carbon has the 250watt Bofeili motor with a peak of 650 watts. If it had the 350 watt Bofeili motor that one is rated at 80 N-m of torque.

Boefili-mid-motor.jpg


Since power is critical for you, I'd try and test ride this bike first. It's so light weight and you aren't doing too many miles; however, my concern is that it might not be enough power. You could find a carbon fiber bike and put a strong Bafang BBSHD on it (rated at 1000 watts & 120 N-m torque) and not have to worry.
 
#5
Thank you for your response. Test riding it is not possible since they are on the other side of the country. There is a company "lunacycle" not to far away that sells kits. I wonder if there are any good hardtail and light (carbon fiber?) bikes that are known to work well with the bafang. I think even the 750Watt bbs02 might be enough. Interested more in 2.1"-2.3" tires as well.
 

Thomas Jaszewski

Well-Known Member
#6
Great article, and it cleared a couple of questions up for me. NEXT, perhaps if HONG QUAN is following he can explain. why parts accessibility is so difficult. Why BBS01's just a few years old are not supported. Dealers ares struggling for parts and information. No ties to changes and serial numbers, unannounced changes, and generally poor support. Yet BBSxx are largely purchased by kit builders. Some of us don't modify, just like the kits the way they are, but when repairs are needed we want parts in the hands of our dealers.
 

Thomas Jaszewski

Well-Known Member
#7
You could find a carbon fiber bike and put a strong Bafang BBSHD on it (rated at 1000 watts & 120 N-m torque) and not have to worry.
Be advised that the BBSHD can over power some swing arms. I think you are talking about hard tails so all may be good. However many carbon bikes have larger diameter bottom brackets making BBSxx kits a poor fit. They will also require adapters on most. Look for lists of bikes used. electricbike.com forum and endless_sphere have those lists.
 
#8
Court,
I love your reviews and the information you provide. On the Editors Choice section you still have a mid-drive category considering so many of the 2 wheeler selections are mid-drives? I suggest the honorable mention be subdived between mids and hubs.