New Bosch Drives, Battery & ABS
- Thread starter E-Wheels
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E-Wheels
Well-Known Member
What I found interesting and curious is the departure from the small chain ring in the new design. I have always assumed the efficiency and reliability that the Bosch system is known for was gained from the ability of allowing the motor to spin faster as most electric motors perform better at higher RPM. Another question to ponder is now that the new design has gone with the bigger chain ring and has achieved a quieter drive does that suggest they are also using a belt in the motor similar to the Brose system
Ravi Kempaiah
Well-Known Member
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- Canada
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- Halifax
You're mistaken!
The motor still runs at high rpm but the gearing is different.
And if you thought Bosch was the most efficient, then you certainly need to put more saddle time on the other systems
Trail Cruiser
Well-Known Member
The Bosch drive is unique compared to other mid drives on how the transmission of power is directed.
The traditional mid drive systems (all mid drives except Bosch) utilizes the regular chain ring and the electric drive undergoes a 2 stage gear reduction process before it joins the human foot power at the chain ring. When the motor is off, it feels just like a regular bicycle (a note worthy advantage over Bosch) with your every pedal effort transmitted directly to the chain ring.
The Bosch is different since not only is the motor geared down but the pedal power is also geared up so that both meet at the in-between ratio (the Bosch chain ring) where it rotates at 2.5 times faster than the pedal speed. If the motor is off, the pedal power is geared up before it goes to the small chain ring. Compared to the direct foot-to-chain ring drive of traditional mid drives, the Bosch losses some mechanical efficiency along the process. So Bosch is not ideal if you intend to switch the motor off most of the time (plus there is unnecessary wear and tear of the gears when you do it).
However, there is a positive side to it. Because of the way the motor is geared, it has a higher transmission efficiency compared to the 2 stage gear reduction of the traditional mid drives. The Bosch motor is more efficient in sending power down to the rear wheels. If you intend to use your pedal assist even at the lowest level, then the Bosch mid drive is more efficient.
But that's all going to change since the new Bosch is rumored to use the standard chain ring.
The traditional mid drive systems (all mid drives except Bosch) utilizes the regular chain ring and the electric drive undergoes a 2 stage gear reduction process before it joins the human foot power at the chain ring. When the motor is off, it feels just like a regular bicycle (a note worthy advantage over Bosch) with your every pedal effort transmitted directly to the chain ring.
The Bosch is different since not only is the motor geared down but the pedal power is also geared up so that both meet at the in-between ratio (the Bosch chain ring) where it rotates at 2.5 times faster than the pedal speed. If the motor is off, the pedal power is geared up before it goes to the small chain ring. Compared to the direct foot-to-chain ring drive of traditional mid drives, the Bosch losses some mechanical efficiency along the process. So Bosch is not ideal if you intend to switch the motor off most of the time (plus there is unnecessary wear and tear of the gears when you do it).
However, there is a positive side to it. Because of the way the motor is geared, it has a higher transmission efficiency compared to the 2 stage gear reduction of the traditional mid drives. The Bosch motor is more efficient in sending power down to the rear wheels. If you intend to use your pedal assist even at the lowest level, then the Bosch mid drive is more efficient.
But that's all going to change since the new Bosch is rumored to use the standard chain ring.
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E-Wheels
Well-Known Member
@Ravi, I only stated the Bosch system was efficient....not the most efficient.You're mistaken!
The motor still runs at high rpm but the gearing is different.
And if you thought Bosch was the most efficient, then you certainly need to put more saddle time on the other systems
I assumed that the progression to the larger chainring would mean less motor & transmission RPM and therefore the benefit of less noise. If this is not the case then the broader question is why the change. Whatever the reason hoping the new drive continues to support the positive reputation that the Bosch system has in the ebike space
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Could Bosch be attempting to widen their market with the new 'entry level' drive? Since one aspect of the new motor is a quieter experience for the user, they may be aiming for manufacturers that design for the rental market at hotels, theme parks and vacation destinations. Since most of these end users just want to tool around at a reasonable speed and enjoy the scenery, this might suit the bill. On the other hand, the mountain bike types are not that impacted with the current design performance line (including CX) motors, thus the two prong approach.
We shall see.
We shall see.
Anybody in the industry heard anything about Bosch's plans for bringing the PowerTube batteries to the US market? Manufacturers are starting to announce their 2018 lineups with October/November releases for PowerTube models. Bosch's US ebike (Link Removed - No Longer Exists) makes no mention of the new batteries (or new Active Line motor) while their international (Link Removed - No Longer Exists) does. I wonder if this is going to be like the Nyon. I've been wanting to upgrade from my 2015 Specialized Turbo X to a mid-drive. In my testing, I prefer the Bosch motors to the others, but aesthetically I want an integrated battery. I got very excited when I first saw this thread, but once I saw Riese and Muller's new Chargers and Superchargers weren't going to be available in the US, I had a feeling it was because of a lack of Bosch support.
I've thought about this since I read the same notice about the R&M Charger being delayed for US release. I think Bosch is playing the long game here, knowing that our market is in its infancy relative to Europe. They may not want to risk the brand by releasing cutting edge products first in America. They are well established in Europe, so a product that may be less durable (take Nyon, for example) might be acceptable there, since the repair/replace network is ubiquitous. From what I understand, Bosch has contracted with Magura to act as a warranty representative here in the States; their contract may impose some limitations on the allowed product range.
Chris Nolte
Well-Known Member
The issue is that Bosch has taken the prudent move of getting UL certification on their batteries. No other ebike motor system supplier does this and I think it makes sense, but the trouble is the testing is very stringent and time consuming. It helps me rest easy when I know my shop is full of batteries that have been tested extensively and backed by a 60 Billion dollar company.
That being said this is a fast moving market and many are looking for the latest and greatest like most markets related to tech.
Hopefully we'll have more news soon after some key meetings in the coming months.
That being said this is a fast moving market and many are looking for the latest and greatest like most markets related to tech.
Hopefully we'll have more news soon after some key meetings in the coming months.
Trail Cruiser
Well-Known Member
Still prefer the classic battery shape over the power tube since a spare battery fits nicely in a back pack and is easier to carry. Here's the 2018 Trek with the classic battery.
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