Bosch CX - is it possible to reduce pedeling resistance with aftermarket mods

bikey850

Pedelecer
Aug 22, 2016
95
14
119
UK
Hi,

For those who have been inside the Bosch CX motors or know about how they work in a bit of detail...

Is it technically possible to reduce the pedeling resistance from the system by replacing any of ther internal components (gears, bearings, etc) to reduce the losses in the system? Is that where the pedeling resistance comes from?

Are there any aftermarket companies who would overhaul the motor but also be able to reduce the pedeling resistance at power cut-off? Is this possible with "better" components or is it simply not possible to modify the system to reduce these without a complete re-design?

I am asking as it would be good to send off a motor for overhaul/service and get it back with these improvements. I apprecaite that the waranty would be out the window at this point however a strong third party support network is available for Bosch motors.

Many thanks in advance for your thoughts.
 

soundwave

Esteemed Pedelecer
May 23, 2015
8,852
3,690

even if you put the best money can buy bearings in the hole motor assembly i doubt you would notice the difference as the mass of all the gears inside will still be there and still have to spin the motor gear with no power.

best option is to get a dongle and forget about it ;)
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
1,186
161
Basildon
The answer is no. It's the basic concept of the motor that causes the drag, where it has the drive sprocket not turned directly by the pedals.
 

Darren Hayward

Finding my (electric) wheels
Mar 25, 2015
9
0
56
It's not frustrating, its engineering. The CX motor gives 50% more torque than the ALP because its internally geared. You have to overcome the gearing to pedal unpowered. You can't have the extra power without the gearing. For anyone who expects to pedal unpowered the ALP is the better choice.


Darren
 

MarcusT

Finding my (electric) wheels
May 5, 2019
11
4
NE Italy
Engineering can still be frustrating, can it not?
I use my EMTB for hill climbing, so I appreciate the extra torque, but when I am on smooth flat roads and begin to feel that drag, it is...frustrating. o_O
 

Artstu

Esteemed Pedelecer
Aug 2, 2009
2,255
844
It's not frustrating, its engineering. The CX motor gives 50% more torque than the ALP because its internally geared. You have to overcome the gearing to pedal unpowered. You can't have the extra power without the gearing. For anyone who expects to pedal unpowered the ALP is the better choice.
I'm sure they could get as much from the active line style if they wanted to.
 

Nev

Esteemed Pedelecer
May 1, 2018
531
506
60
North Wales
I went for a ride the other day with a mate of mine, we are same age and similar levels of fitness. I was on an APL powered racing type bike he was on a CX powered mountain bike. On the flat, down hill or slight up hill gradients I was much faster than him. On steep hills however I could not live with him. That extra 50% of Torque makes a big difference when the going gets very steep.
 

Related Articles

Advertisers