Bosch eBike Systems Motor Comparison

[Admin]

Hi guys! I was in Irvine, California today visiting Bosch eBike Systems and got to test ride all of their motors back to back... so, I made a video about it! 2018 is the first year for the redesigned Active Line and Active Line Plus, which are extremely quiet. They are much lighter, physically smaller, and use a 1 to 1 chainring so pedaling with the bike off or above the top assisted speed of 20 mph isn't impacted by reduction gearing (as it is with the older Active Line motors and all current Performance Line motors. My experience has been that the reduction drag isn't that big of a deal, but it's something that does differentiate Bosch from all other mid-motor manufacturers except for TTIUM, which I reviewed last year on the PESU Monster.

Good things about Bosch Electric Bike Motors:

• Extremely responsive (senses rear wheel speed, pedal cadence, and pedal torque, 1,000+ times per second)
• Offers shift detection (listens for pedal torque change and shifter tension changes to reduce motor power and protect your chain, sprockets, and derailleur)
• Very reliable, I hear e-bike shops tell me that they require less maintenance and that getting parts is relatively easy
• Excellent two-year warranty with many service centers

Trade-offs about the Bosch E-Bike Motors:

• One of the most expensive drive systems (becoming cheaper now that they have the less powerful Active Line options)
• Not compatible with any throttle systems, they only support Class 1 and Class 3 type of ebikes
• Relatively heavy at 8.8 lbs for the Performance Line drive units, the new Active Line are lighter at 7.1 and 6.3 lbs
• The Performance Line motors are louder because of the reduction gearing, and this also creates some friction and drag when unassisted or above motor supported speeds

Bosch has a great chart of all the motor specs for each model that you can explore here, but I also took a screenshot because this page may change over time as Bosch introduces new ebike motors or makes adjustments to their website. I'll drop in to answer questions and stuff here over time, but I always appreciate hearing your thoughts and experiences. I'll be traveling most of this month and posting reviews and stuff whenever I can



Other technical details about the Bosch drive system follow, all measurements are related to 2018 products and may describe prior years.

• Performance Line motors and the first generation of Active Line have a 180 mm Q Factor or "thread point" which is the distance between the pedal attachment points on the crank arms, when measured parallel to the bottom bracket axle. This is somewhere in the middle when compared to the Yamaha PW-X with 168 mm, the Shimano E8000 with 175 mm, Brose T and S with 190 mm, and Panasonic with 207 mm. My understanding is that a traditional non-electric mountain bike Q Factor would be 147 mm, but with Plus sized tires and fat tires, many have become wider.
• Performance Line motors and the first generation of Active Line motors have a standard ISIS Drive splined spindle but the new smaller Active Line and Active Line Plus motors have a Bosch-developed Mini ISIS Drive splined spindle. What I'm talking about here is the design for how crank arms slide onto the spindle, splined designs offer more ridges than square tapered and as a result are sturdier, more reliable, and more responsive.
• Performance Line motors and the first generation of Active Line motors used a reduction gearing system that made the chainring turn 2.5 times for each crank revolution but the new smaller Active Line and Active Line Plus have a standard sized chainring that spins 1 to 1, does not introduce gearing friction when pedaling unassisted or above the maximum supported speed, and can be pedaled backwards to actually move the chain through the rear gearing setup whereas the other systems just freewheel backwards. I was told that one benefit of the older design was improved chain retention but I heard about some cases of chain suck and it definitely brought the chain closer to the right chain stay, causing increased contact and paint chipping on many frame designs. Part of what makes the new Active Line motors so compact and lightweight is that they do not contain as many gears.

Feel free to suggest corrections, share the Q Factor of the new Active Line motors, or add additional technical detail with your comments below and I'll work to update this main entry ongoing

 

[Lynn Recker]

Looking at their webpage here. And remembering some of your prior reviews, especially of Riese & Mueller ebikes with Chris at Propel, brings some confusion to my mind. R&M produce speed pedelec's with the Nuvinci and Rohloff hub gears systems, but Bosch doesn't list hub gear system spec's under its Performance Line Speed motor. Is it just that Bosch doesn't list that spec, but the motor is still usable - and at the same spec's as the derailleur system?

And why would the spec's be lower for a hub gear system compared to a derailleur?

And furthermore, the hub gear system spec does not include shift detection? Is that technically true for the motor unit or is it just that a hub gear system doesn't provide the feedback to the motor that a derailleur system would?

I also remember that you tested a bike (possibly with a the ebike's factory rep - or maybe Chris) and they mentioned that hub gear systems like the Nuvinci did not provide the power that a good derailleur system would with the same motor. Looking at the Bosch drive-units page, one is led to believe that Bosch drive-units meant for use with hub gear systems are "de-tuned" in some way. Is that true and is that why that person (the rep or Chris) then said the performance with the Nuvinci was less than the derailleur system? Or is it just that the use of the different gearing systems translates the power differently? Though I cannot see how that would happen. If it's actually a "detuned" Bosch drive-unit/motor for the hub gear systems, what's to stop a company from buying the version for the derailleur system and puting it on their hub gear ebikes instead? Are some ebike producers doing just that?

Or does it have to do with the size of a chain sprocket vs that used for a Gates belt drive?

The more you know... you know, the less you know. This just got me full of it! Questions, that is.

 

[Johnny]

Active line would be great for road bikes or hybrid commuters since it doesn't have much drag without power. Also for a fit rider the active line will be plenty, result in a slightly lighter bike. They need to offer a derestricted 28mph version.

 

[VirgilCaine]

I wonder how the active line and active line plus compare to the Brose as far as noise level ?

 

[Admin]

I wonder how the active line and active line plus compare to the Brose as far as noise level ?

My experience is that they are similar, and quieter at high RPM. Brose is super quiet at lower RPM but the T and S drive units offer a lot more power and torque, up to 90 Nm, and higher ~120 pedal RPM support, so it's understandable that they can get louder... but not much. Here's a video comparison I made showing the mountain drive units back to back, including Brose:

 

[Admin]

Active line would be great for road bikes or hybrid commuters since it doesn't have much drag without power. Also for a fit rider the active line will be plenty, result in a slightly lighter bike. They need to offer a derestricted 28mph version.

Yeah! I could see Bosch moving more of their designs to a full sized chainring long term, I do think that the smaller sprockets offer super-quick start and stop power as well as a mechanical advantage for the motor. Bosch was one of the first big companies to develop a high performance mid-drive and perhaps the reduction gearing was necessary to make it work early on. Jonathan was chatting with me about the Active naming and suggested that these motors are great for active riders, just like you suggested. I think they offer a balance of no-resistance with gentler input, so it can sort of trick you into feeling "freer" even though you're not getting as much support as the Performance Line motors. I have ridden all of the current-gen ebike motors and the Yamaha, Shimano, Brose, and Bafang all use 1 to 1 gearing and have no drag... but you still feel the wind resistance and a hard change when going from assisted 20 mph to unassisted 21 mph. I think that a lot of it is mental, there's not a lot of friction in the reduction gearing system and the 165 to 175 mm crank arms give you an enormous mechanical advantage over the gears.

 

[Voz]

Coupling the Bosch Performance Speed with a Nuvinci hub is possible and compatible. I currently am riding a loaner bike with that configuration. The drive has a warranty that has been extended from 2 to 5 years, so the bike manufacturer is totally confident that this is authorized by Bosch.

This being said, I absolutely would not recommend choosing this configuration if you want to climb steep hills. The 350W Bosch Performance Speed is really fairly weak and needs proper gearing. I stall on a 8% grade hill every morning with this combo (BPS + N380) simply because there is a 20km/h downwind.

The BPS + N380 combo is really very pleasant in small rolling hills, but I would never buy it for anything more challenging. The motor simply doesn’t have enough torque and power.

Hi there. I was thinking about upgrading my Bosch CX bike from the 11-36 gears to either an Alfine 8 or Nuvinci N380. How do you feel the CX would handle the 8%+ hills?

Also, would you happen to know if Shimano DI2 or Nuvinci Hsync/Harmony will plug right into the Bosch motor and work as an auto? I have seen bike manufacturers offering Alfine DI2 & Nuvinci integrated but am not sure if it will work adding these hubs aftermarket?

 

[VirgilCaine]

Great stuff ! That's the review I was hoping to see. Thanks so much.

 

[Admin]

Looking at their webpage here. And, remembering some of your prior reviews, especially of Riese & Mueller ebikes with Chris at Propel, brings some confusion to my mind. R&M produce speed pedelec's with the Nuvinci and Rohloff hub gears systems, but Bosch doesn't list hub gear system spec's under its Performance Line Speed motor. Is it just that Bosch doesn't list that spec, but the motor is still usable - and at the same spec's as the derailleur system?

And why would the spec's be lower for a hub gear system compared to a derailleur?

And furthermore, the hub gear system spec does not include shift detection? Is that technically true for the motor unit or is it just that a hub gear system doesn't provide the feedback to the motor that a derailleur system would?

I also remember that you tested a bike (possibly with a the ebike's factory rep - or maybe Chris) and they mentioned that hub gear systems like the Nuvinci did not provide the power that a good derailleur system would with the same motor. Looking at the Bosch drive-units page, one is led to believe that Bosch drive-units meant for use with hub gear systems are "de-tuned" in some way. Is that true and is that why that person (the rep or Chris) then said the performance with the Nuvinci was less than the derailleur system? Or is it just that the use of the different gearing systems translates the power differently? Though I cannot see how that would happen. If it's actually a "detuned" Bosch drive-unit/motor for the hub gear systems, what's to stop a company from buying the version for the derailleur system and puting it on their hub gear ebikes instead? Are some ebike producers doing just that?

Or does it have to do with the size of a chain sprocket vs that used for a Gates belt drive?

The more you know... you know, the less you know. This just got me full of it! Questions, that is.

Hi Lynn, I got a reply back from Bosch that might help to clarify and answer your question:

• IGH is indeed compatible / usable with PL Speed (though not listed in our Product Catalogue)
• PL Speed is slightly de-tuned when using IGH vs. derailleur to protect the drivetrain due to lack of shift detection. Shift detection not possible using IGH.
• eBike manufacturers are trained to install the slightly detuned “PL Speed with IGH” when coupled on bikes with IGH.

 

[Alaskan]

I am awaiting a Rise & Muller Nevo Nuvinci GH with the Bosch CX drive .

Is anyone aware if Bosch has de-tuned wattage or torque or somehow compromised the CX drive system when it is coupled with a Nuvinci CVT?

Given that I live at the top of a fairly steep hill, this gives rise to a mite of concern.

 

[Voz]

I would recommend a demo. It depends how important hills are for you. If you have an occasional 10% grade, you’ll do just fine. Now the CX has more torque than the Speed line, and that will no doubt help. Your fitness level and weight makes a difference too. I weigh 220 for 6ft, am over 50 and moderately fit. On a windless day, I’ll struggle starting at 10-12% with the Nuvinci. But on a windy day the Performance Speed combined with N380 is really tough. It’s not my bike (mine is in workshop) but I have about 2000 kilometers on it, between rides this summer and this winter. Overall I like the Nuvinci a lot, but feel that if want to climb with it frequently you need a pretty strong motor. An 11-42 cassette pairs nicely with the Bosch Performance Speed, as it masks the relative lack of torque of the 28mph drive. I’ve ridden the Haibike Xduro S5.0 on hills and had no major complaints.

Not sure I could comment on Bosch + Alfine 8 as I’ve used it wth an E6000 a lot. I’ve no idea if the two are able to communicate in order to sync the gearshifts.

Thanks, that is an excellent real world experience. Maybe I will just stick with the 11-36. I agree that a ride demo is required before committing to this upgrade. We are the same weight, age and fitness so your review is good for me.

 

[Voz]

I made a video of a hill climb this summer. The climb peaks off at about 15% grade. It's with the Bosch Performance Speed 45km/h + N380. In the video you can see that under 10% grade, I was basically doing Ok. But above, it got really tough. Windless day, of course. The grade isn't always 100% correct, due to walls and other obstacles. But it's more or less correct for the part of the climb up to 15% grade.

I had watched your video a few times before when researching Nuvinci!

I am thinking that the CX mid drive would cope a little better than the Performance Speed?

Have you tackled that hill with the usual 11-36 cassette setup and if so what was the comparison?

Cheers

 

[e-boy]

Court ,
What's you pick for on road hilly terrain ?

I assume the results would be the same .

 

[Dmitri]

Looking at their webpage here. And remembering some of your prior reviews, especially of Riese & Mueller ebikes with Chris at Propel, brings some confusion to my mind. R&M produce speed pedelec's with the Nuvinci and Rohloff hub gears systems, but Bosch doesn't list hub gear system spec's under its Performance Line Speed motor. Is it just that Bosch doesn't list that spec, but the motor is still usable - and at the same spec's as the derailleur system?

And why would the spec's be lower for a hub gear system compared to a derailleur?

And furthermore, the hub gear system spec does not include shift detection? Is that technically true for the motor unit or is it just that a hub gear system doesn't provide the feedback to the motor that a derailleur system would?

Maybe I can answer some of the questions here:

• The Bosch manufacturer's documentation does in fact include the gear hub in the list of possible applications for the CX motor except CX Speed. Of course, we know that manufacturers such as Heisenberg (now Nikolai) do Rohloff+Speed so we know it's possible.
• Rohloff has plenty of additional requirements on its hubs, particularly to have a chain tensioner. Notice how very few manufacturers actually add one.
• Rohloff also requires a snubber wheel when used with the Gates drive. And yet, notice how e.g. Heisenberg Fully does not actually use one.
• Regarding shift detection, I don't know about other hubs, but you cannot shift Rohloff under load. At all. You cannot even have your foot pressing on a pedal, let alone have the motor working. The only shift-detecting Rohloff system is of course the Rohloff E-14 which integrates with Bosch... this has only just come out, we need to see how it is.

TL;DR Bosch doesn't list some things and manufacturers can and will ignore build recommendations.

 

[Islandrog]

Looking at their webpage here. And remembering some of your prior reviews, especially of Riese & Mueller ebikes with Chris at Propel, brings some confusion to my mind. R&M produce speed pedelec's with the Nuvinci and Rohloff hub gears systems, but Bosch doesn't list hub gear system spec's under its Performance Line Speed motor. Is it just that Bosch doesn't list that spec, but the motor is still usable - and at the same spec's as the derailleur system?

And why would the spec's be lower for a hub gear system compared to a derailleur?

And furthermore, the hub gear system spec does not include shift detection? Is that technically true for the motor unit or is it just that a hub gear system doesn't provide the feedback to the motor that a derailleur system would?

I also remember that you tested a bike (possibly with a the ebike's factory rep - or maybe Chris) and they mentioned that hub gear systems like the Nuvinci did not provide the power that a good derailleur system would with the same motor. Looking at the Bosch drive-units page, one is led to believe that Bosch drive-units meant for use with hub gear systems are "de-tuned" in some way. Is that true and is that why that person (the rep or Chris) then said the performance with the Nuvinci was less than the derailleur system? Or is it just that the use of the different gearing systems translates the power differently? Though I cannot see how that would happen. If it's actually a "detuned" Bosch drive-unit/motor for the hub gear systems, what's to stop a company from buying the version for the derailleur system and puting it on their hub gear ebikes instead? Are some ebike producers doing just that?

Or does it have to do with the size of a chain sprocket vs that used for a Gates belt drive?

The more you know... you know, the less you know. This just got me full of it! Questions, that is.

Currently riding an Electra Townie Go 8i (Shimano 8 speed internal gear) with the Bosch PL motor. Found this Bosch page that gives performance of each of the Bosch engines comparing internal and derailleur specs. You have to scroll down....
https://www.bosch-ebike.com/us/products/performance-line/

 

[Rune]

………..

The Performance Line motors are louder because of the reduction gearing, and this also creates some friction and drag when unassisted or above motor supported speeds

…………...

Performance Line motors and the first generation of Active Line motors used a reduction gearing system that made the chainring turn 2.5 times for each crank revolution but the new smaller Active Line and Active Line Plus have a standard sized chainring that spins 1 to 1, does not introduce gearing friction when pedaling unassisted or above the maximum supported speed, …...

Could this drag be quantified and compared to other motors? I have seen one test that compared the total drag or loss of pedal power between pedal and back wheel for a few bikes, but not for just the motor.

 

[Dmitri]

Here's something else that's interesting: we don't see many Bosch-driven fatbikes, but apparently the way to support a larger chainline is to physically position the motor to the right of the frame (I kid you not!) and then use spacers (Miranda) and cranks with different Q factors.