Tuning PAS

Dynz

Dynz

Member
Region
United Kingdom
I was wondering if anyone has tuned their PAS to be a bit more reactive than stock. I find that the motor takes a bit too long to kick in after initially starting to pedal (like half a rotation of the crank arms) , and keeps engaging for a bit too long after I've stopped pedaling.
This has felt dangerous at times, especially when having to suddenly slow down in traffic. I don't use the brake sensors by the way.

Can someone recommend a more smooth programming setting?
 
To get the motor to engage more quickly adjust the Start Degree to a lower number. 5 gives you about a quarter crank and I like this number because it allows me to shift under no load after coasting or an unplanned breaking situation such as a suicidal squirrel crossing.
On the BBS02B the motor run on after pedaling is caused by the Stop Delay setting. Problem being is if you go below 20 ( or possibly 25) it makes the PAS act weird and jumpy. I've left mine at 25 for this reason. This also assists in no load shifting if you shift and stop pedaling at the same time as the run on will make the shift as the motor disengages. I feel it also smooths things out. Remember your break stops the motor instantly and I've come to appreciate the smoothness added by the run on.
Current Decay and Stop Decay also add a minute bit of run on but also make for a much smother PAS experience. 6 and 10 respectively seem to work well when used with my other settings.
Raising the Keep Current to 90 -100 also make for a smother experience in my opinion.
Understand that there are many variables such as bike and rider weight, gearing and style of riding to name a few that affect how PAS feels to a rider.
I ride to exercise and want minimal PAS intervention. . .only to assist on hills or when I start to tire. . . so these settings end up being very personal


RER.jpg
8
 
Gonna give these a go, cheers. Weather has been horrible over the past few weeks, itching to ride dude!
 
Dynz said:
Gonna give these a go, cheers. Weather has been horrible over the past few weeks, itching to ride dude!
Click to expand...
Keep in mind that these interact with the settings on page 1 so YMMV.
Also keep in mind that I try to shift gears as if I'm pedaling without a motor. . these all affect how the motor feels.
What's your style of riding? Or what do you want the motor to do for you?
Yeah it sucks when the weather doesn't cooperate. It's been beautiful here so I've been making up for slackin' all winter.
 
Dynz said:
Gonna give these a go, cheers. Weather has been horrible over the past few weeks, itching to ride dude!
Click to expand...
That was all good info.

Here are some more links
https://electricbike-blog.com/2015/06/26/a-hackers-guide-to-programming-the-bbs02/
https://talesontwowheels.com/2021/01/18/bbshd_settings_programming/
https://electricbike-blog.com/2016/...assist-on-singletrack-without-getting-killed/

Im in the final stages of a BBSHD build and will be exploring all this info very soon.
 
linklemming said:
That was all good info.

Here are some more links
https://electricbike-blog.com/2015/06/26/a-hackers-guide-to-programming-the-bbs02/
https://talesontwowheels.com/2021/01/18/bbshd_settings_programming/
https://electricbike-blog.com/2016/...assist-on-singletrack-without-getting-killed/

Im in the final stages of a BBSHD build and will be exploring all this info very soon.
Click to expand...
Those are all great references and probably what all of us have read in order to get a better understanding.
 
Did I miss something? Like the part where our OP stated he's working with a Bafang mid drive?

In my experience, MANY (most?) PAS systems are NOT adjustable. No way, no how. If you'd like to mess with that delay prior to the assist turning on, check out the PAS sensor. Count the magnets on the ring. Then find one with MORE magnets and try that.

The way that delay works, is the controller is counting the number of magnets passing the sensor prior to it starting. Lets say it's looking for 3-4 magnets to pass the sensor prior to turning the power on, and you disk has 6-8 magnets. If you were to install, say a 12 magnet sensor, the controller would still be looking at those first 3-4 magnets. Now though, instead of those 3-4 magnets being 1/2 a turn of the crank, using a 12 magnet sensor those 3-4 pulses will only be 1/4 of a turn of the crank....
 
Gionnirocket said:
Or maybe pick up a bbs for Michigan
Click to expand...
Oh man, I AM in the process of picking out another bike. I didn't know it showed already. Ton's of indecision of course, but I have to tell you nothing final, but it's likely going to be a geared hub drive, and possibly a torque assist equipped geared hub. Don't want to drag this topic off course with all that though....
 
Gionnirocket said:
To get the motor to engage more quickly adjust the Start Degree to a lower number. 5 gives you about a quarter crank and I like this number because it allows me to shift under no load after coasting or an unplanned breaking situation such as a suicidal squirrel crossing.
On the BBS02B the motor run on after pedaling is caused by the Stop Delay setting. Problem being is if you go below 20 ( or possibly 25) it makes the PAS act weird and jumpy. I've left mine at 25 for this reason. This also assists in no load shifting if you shift and stop pedaling at the same time as the run on will make the shift as the motor disengages. I feel it also smooths things out. Remember your break stops the motor instantly and I've come to appreciate the smoothness added by the run on.
Current Decay and Stop Decay also add a minute bit of run on but also make for a much smother PAS experience. 6 and 10 respectively seem to work well when used with my other settings.
Raising the Keep Current to 90 -100 also make for a smother experience in my opinion.
Understand that there are many variables such as bike and rider weight, gearing and style of riding to name a few that affect how PAS feels to a rider.
I ride to exercise and want minimal PAS intervention. . .only to assist on hills or when I start to tire. . . so these settings end up being very personal


View attachment 883838
Click to expand...
Forgot to mention - I changed my settings to your recommended ones and it made for quite a difference! Good shout man!
 
You got lucky... usually I'm only right on the first Tuesday of the month 🙃

Now tweak it to your style. Don't give too much weight to number values and just take note of how any change you make feels. The oddity is the settings interact and I don't think it fully understood....but with a little experimenting you can get it to do what you want.
 
😂
It's proper hard you know!
As someone else said it's more of a manual. Gonna change the 9v minimum on the throttle back to 11v as it's easier that way to pull the wheel up.
 
Dynz said:
😂
It's proper hard you know!
As someone else said it's more of a manual. Gonna change the 9v minimum on the throttle back to 11v as it's easier that way to pull the wheel up.
Click to expand...
I'm sure it is... It's been 40 years for me and it's only going to get longer.
I guess you could also adjust the Throttle Start Current... but go easy as you can take out the controller getting too aggressive.
 
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