Bafang/Bosch PAS

[satcat]

Hi, Does anyone know how the PAS levels of a Bafang motor compared with Bosch ones.
I presume Bosch "turbo" level is the same as Bafang PAS level 9., but what about the other Bosch levels, Eco, Sports, how to they compare with Bafang levels ?

 

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[matthewslack]

Hi, Does anyone know how the PAS levels of a Bafang motor compared with Bosch ones.
I presume Bosch "turbo" level is the same as Bafang PAS level 9., but what about the other Bosch levels, Eco, Sports, how to they compare with Bafang levels ?

Bosch does not have PAS levels, because it is a torque sensor system. It measures how hard the rider is pedaling, and the motor adds a multiple of that - up to 400% in the higher Bosch modes. If the rider pedals harder, the motor automatically adds more. If the rider eases off, so does the motor.

Each bafang PAS level is a fixed amount of either power or torque - can't remember which, but someone will know! - so if the rider pedals harder or eases off, the motor stays the same. If the rider wants a different level of help, they must change the PAS setting.

So completely different to ride. The actual amount of assistance is configurable for both systems. Easy on a bafang, via a phone app I think for the bosch.

Both systems (assuming lowest power bafang BBS01) are nominally 250W continuous, but both will give more power during short periods like hills or acceleration from rest.

 

[The Silverfox]

Bosch does not have PAS levels, because it is a torque sensor system. It measures how hard the rider is pedaling, and the motor adds a multiple of that - up to 400% in the higher Bosch modes. If the rider pedals harder, the motor automatically adds more. If the rider eases off, so does the motor.

Each bafang PAS level is a fixed amount of either power or torque - can't remember which, but someone will know! - so if the rider pedals harder or eases off, the motor stays the same. If the rider wants a different level of help, they must change the PAS setting.

So completely different to ride. The actual amount of assistance is configurable for both systems. Easy on a bafang, via a phone app I think for the bosch.

Both systems (assuming lowest power bafang BBS01) are nominally 250W continuous, but both will give more power during short periods like hills or acceleration from rest.

Bosch power modes are only configurable via an app if you have the Nyon display or the Bosch Smart System.

 

[matthewslack]

Bosch power modes are only configurable via an app if you have the Nyon display or the Bosch Smart System.

Everything I've read about modern Bosch bikes gives me the impression most riders would never need to adjust anything as the standard modes cover a very wide range of situations.

 

[The Silverfox]

Everything I've read about modern Bosch bikes gives me the impression most riders would never need to adjust anything as the standard modes cover a very wide range of situations.

Absolutely. I have the Nyon so could adjust the modes but I don't see any reason to make any adjustments, the four modes I have are more than I need. I mainly ride with PAS off then when I'm tired towards the end of a ride and have a hill I switch it to Eco. Very occasionally, for a long, steep hill I switch it into eMTB. Those two modes cover pretty much any situation.

 

[sjpt]

For the (cadence sensor) Bafang motor it depends a lot on the controller, how it is programmed and how it responds to the sensor.

 

[Nealh]

Bosh has power levels used in a not so dissimilar way that current control is used on cadence PAS systems, the bosh eco level is a different power mode then the turbo or emtb mode. If the modes didn't offer varying power/ effort in each level then it would be pointless having them.

 

[guerney]

Hi, Does anyone know how the PAS levels of a Bafang motor compared with Bosch ones.
I presume Bosch "turbo" level is the same as Bafang PAS level 9., but what about the other Bosch levels, Eco, Sports, how to they compare with Bafang levels ?

You can set up Bafang power levels however you like, here's mine - I only ever use lower levels when running very low on battery. For my bike, 8% current is enough to get me home, otherwise I use level 9.

 

[Nealh]

You have though no real high torque levels set, all are set for max 100% speed in the basic tab. If one sets the higher current limits to a lower speed level like 60% or so one should theoretically gain more torque, one can't really have max speed and current. Much like a battery one can have a 17ah battery but one one won't get all those ah if used in max current draw mode so it's a trade off off range over power.

 

[guerney]

You have though no real high torque levels set, all are set for max 100% speed in the basic tab. If one sets the higher current limits to a lower speed level like 60% or so one should theoretically gain more torque, one can't really have max speed and current. Much like a battery one can have a 17ah battery but one one won't get all those ah if used in max current draw mode so it's a trade off off range over power.

I'm always willing to try other settings... I've been mucking about with these settings all year - in use, I get increasing levels of torque with levels 1 to 9. The battery struggles to supply enough current at level 9 sometimes on steep hills, but only when running low on battery, but otherwise level 9 gets me a bike which flies along the road with no effort expended. Which saves my old knees. I might experiment with the speed limits on the low levels/my eco modes. At level 1, it's programmed to provide (or attempt) 8% of 15A. The"Speed limit" is the percentage of cutoff assistance of the speed limit (15mph), set by either the display or the controller firmware - in my case the display controls the speed limit. I'm sure that my 19.2ah (LG MH1 cells, as you correctly deduced) battery's ability will decrease as it degrades, but at the moment it's coping well (despite being stinky since purchase). For very long journeys when I'm running very low on battery, I set "Keep current" to 60% ie level 1 would be 8% of 60% of 15A, providing assistance to 100% of the speed limit of 15mph. Since changing "Keep current" to 100% of 15A, I mostly use level 7 (80% of 15A) - I must be getting fitter, despite my non-efforts.

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[Nealh]

If using the bike for towing heavy veg and using hills, go for more torque. Try using high current with a much lower speed set in the limit tab, then one should gain better current supply at the expense of the motor also trying to maintain speed.
Mix and match the setting so you have 5 or 6 fast power settings for non towing and 2 or 3 for power/torque with low speed. Try setting the last 3 settings for towing and the first 1/2 dozen for speed and power on the flat.

 

[guerney]

If using the bike for towing heavy veg and using hills, go for more torque. Try using high current with a much lower speed set in the limit tab, then one should gain better current supply at the expense of the motor also trying to maintain speed.
Mix and match the setting so you have 5 or 6 fast power settings for non towing and 2 or 3 for power/torque with low speed. Try setting the last 3 settings for towing and the first 1/2 dozen for speed and power on the flat.

That's very useful! Yes, I'll fiddle about with these settings more later on in the year. It's great that the Android app would allow me to reprogram on the the roadside, leaning against a Homcom folding trailer full of pumpkins - I must load that onto my phone.

 

[satcat]

Thanks all for explaining how bafang and Bosch systems differ.
I have the bafang 250w 36v, I have changed all my speed limits to 100% and left everything else alone.
I have also taken my throttle off. (stops me cheating)
I find 3 PAS levels are enough and mostly use PAS 2.