EMTB mode Bosch gen4 cx

[fibersnap]

Perhaps I did not look hard enough, but I'm confused by Bosch's description of EMTB mode. I have gen4 cx with Purion in a 2022 Orbea Wild h30.
Does EMTB adjust only "in the moment" - i.e. does it only care how hard I am pushing on the pedals? Or is there some other considerations, like speed, battery left etc?
Sometimes the bike feels more sluggish even if I'm always in emtb, so I'm curious if the controller is "thinking for me" and trying to get me to produce more of my own wattage?
Basically, if I'm being a lazy fatass, does Purion give me a gentle nudge by lowering output?
Thanks!

 

[JP-NZ]

From Bosch's own website..

The eMTB mode provides you with targeted support for eMountain biking and always delivers power exactly when you need it. Whether on steep sections or individual obstacles. This is precisely when it delivers up to 340% of the rider's own power and a maximum torque of 85 Nm. This is how the power for the Uphill Flow is created.

How much power the eMTB mode provides depends on the pedal pressure. Sensors measure the load more than 1,000 times per second to achieve the optimal motor response: fast, but particularly sensitive power delivery that adapts to your needs. Because maximum torque is available over a very wide cadence range, you'll make better progress in any riding situation.

 

[Bones]

And if you get the emtb plus software update it gives you an extra 20% battery saving at the expense of limiting boost mode.
So you're fat arse will suffer a bit more

 

[Shark58]

Does EMTB adjust only "in the moment" - i.e. does it only care how hard I am pushing on the pedals?

Yes.

? Or is there some other considerations, like speed, battery left etc?

No.

The eMTB mode reacts solely to rider input and dynamically moves the support factor between 140% (TOUR) and 340% (TURBO) up and down.

To give you an indication how hard you need to work: To reach the maximum of 340% support you will need to input over 190 W when the regular eMTB mode is installed. In case you have the eMTB mode for short cranks (165 mm or less) installed you still need to input about 180 W to get 340% from the motor.

 

[Yoak]

A few factors to consider. If the battery has less than 20 or 25% (I don´t remember) left you get less power from the motor. If you pass the local "speed limit" on the motor (25km/h in Europe) it feels like you have breaks on. One last thing is that if you have been rolling without using pedals and you are in a (to) low gear the motor can feel sluggish before you get the crank arms up to a higher cadence

 

[Mikerb]

as a bove power increases with crank torque but cadence also has a role to play. Whereas in turbo you can get significant motor assist at relatively low cadences, in EMTB mode you need to maintain a higher cadence to get decent motor support. It just means in EMTB you are better of spinning than grinding because of you grind and the bike hits a sticky muddy section, a head wind, or a gradient, it will feel like the power quickly drops. If you spin that will not happen.

 

[Yoak]

And higher cadence will help your motor last longer as it’s under less stress

 

[fibersnap]

A few factors to consider. If the battery has less than 20 or 25% (I don´t remember) left you get less power from the motor. If you pass the local "speed limit" on the motor (25km/h in Europe) it feels like you have breaks on. One last thing is that if you have been rolling without using pedals and you are in a (to) low gear the motor can feel sluggish before you get the crank arms up to a higher cadence

Is the torque reduction in response to low battery only feature of the newer smart system? I have the plain purion.
I'd hate getting less power at end of ride - I can look at display and make decision to drop power myself.
I suppose though that this may be a battery longevity saving feature as the battery is down there may be some problems providing peak voltage?

 

[Yoak]

I’m 99% sure it’s like that with the previous system as well. I used to have it