Second gen Bosch Performance CX question

nate_lynch

New Member
Hi all,

I'm considering getting an ebike with an older Bosch system, to offset the cost a bit, and I'm wondering about how much friction the reduction gearing system creates when pedaling unpowered. I do like the flexibility of pedaling unpowered, and in previous threads in the forum, Court mentioned this as a downside:

  • Part of the noise increase comes from a proprietary reduction gearing design inside the motor, the chainring is a smaller sprocket that spins at 2.5 revolutions for each crank revolution, and this introduces some friction drag, the drag is most relevant to moments when you might be pedaling without the motor turned on or pedaling above the maximum supported speed of 20mph (32km/h)
Does anyone have experience with it? I'm wondering if it would be so much to render it unenjoyable and if I should stick with one of the newer Active Line motors, or if it will just require a bit of extra effort that I could overcome.
 

JohnDoe1983

Active Member
Mine on a flat surface at my age pedalling in lower gear will bring me home. Not fun but safe. Hope to never have to test it in real situation.
 

rich c

Well-Known Member
I've ridden a few miles at 0 assist, but it's my final card in stretching battery range. It lets me have some assist to make it up slight grades. I would not want to do any climbing without some assist. I do consider it unenjoyable.
 

nate_lynch

New Member
Thanks! Good to know it's not just like riding in an imperfect gear. I think I'll look more towards the active line or just wait until the newer performance line bikes get discounted a bit. Much appreciated.
 

rich c

Well-Known Member
Thanks! Good to know it's not just like riding in an imperfect gear. I think I'll look more towards the active line or just wait until the newer performance line bikes get discounted a bit. Much appreciated.
My Mom's family were Lynch people. Immigrated to Delaware and then latter to Central IL. Good luck with your choice.
 

nate_lynch

New Member
Ahh, probably also from Galway I’d bet - there’s a bank in the city with our name on it. Thanks, and slán go fóill
 

Ravi Kempaiah

Well-Known Member
I think I'll look more towards the active line or just wait until the newer performance line bikes get discounted a bit. Much appreciated.

If you have a Trek store nearby, you could demo one of their bikes with Bosch Gen 4 motor system.
Gen 2 motors felt like "you were riding your bike in quicksand" kind of feeling when you pedaled with assist off and they completely redesigned the system in 2019 and the Gen 4 is quicker to respond and accelerate.
In terms of instant engagement, it is very similar to Yamaha PW-X systems and quite smooth in power delivery.
Also, it has minimal resistance when pedaling un-powered. Also, it is quite a bit lighter.
Overall, it is a significant improvement over Gen 2 (I own several bikes with Gen 2 system) and before you make a decision, I suggest you try some bikes with the Bosch Gen 4.
 
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Tomi

New Member
The friction is not only gear loss, it would be 3-6%. The Gen2 friction is a magnetic like brake, you spin the motor as well, the loss is much bigger and somehow strange.
 

CityExplorer

Well-Known Member
if you want to save money get a motor from a different manufacturer, or find a deal on a Gen-4, don't look back on Bosch.