Why are the 9 speed levels set out like this?

Manc44

Pedelecer
Jun 21, 2021
141
24
I was testing my new kit and it's a typical Bafang rear hub with the P850C display and YCSV126-001-48T controller.

Here's the speeds the wheel was doing at each power level 1 to 9 with the bike upside down and no stress on the wheel:

Level 1 = 11.5 MPH
Level 2 = 11.5 MPH
Level 3 = 11.5 MPH
Level 4 = 16 MPH
Level 5 = 21 MPH
Level 6 = 21 MPH
Level 7 = 21 MPH
Level 8 = 26 MPH
Level 9 = 29 MPH

Also, sometimes level 1 doesn't work, but if I go up to level 2 then back to 1, it does.

All I really want is to get up hills, I have no interest in going over 15 MPH. I know "You should have got a mid-drive" but I wanted to keep all my gears and not be completely reliant on the motor, which I would be if I had to do away with my middle and granny chainrings.

If those first three levels all go at 11.5 MPH, does 2 and 3 actually give more power than level 1?

Because I was testing the wheel just spinning it's own weight, the wattage usage was hardly even registering.

I suppose I'll find out when I use the kit properly, I just wondered why it spun at the exact same speed on all 3 of the lowest settings.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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It's a speed controller by the looks of it and I would say is set up for 5 PAS speed levels, each level will have the same current delivery.
 

Manc44

Pedelecer
Jun 21, 2021
141
24
It's a speed controller by the looks of it and I would say is set up for 5 PAS speed levels, each level will have the same current delivery.
Cheers Nealh. By default the P850C was set to 5.

I never even thought to try it on 5 and 3 to see what the MPH was.:rolleyes:
 

AndyBike

Esteemed Pedelecer
Nov 8, 2020
1,474
633
Torque ?
 

Manc44

Pedelecer
Jun 21, 2021
141
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I don't think my setup is capable of it :p

Tonight I properly tested every level:

Here are the speeds the rear wheel goes at with the bike upside down and the wheel only pushing its own weight:

Three Levels:
1 = 11.5 MPH
2 = 21 MPH
3 = 29 MPH

Five Levels:
1 = 11.5 MPH
2 = 16 MPH
3 = 21 MPH
4 = 26 MPH
5 = 29 MPH

Nine Levels:
1 = 11.5 MPH
2 = 11.5 MPH
3 = 11.5 MPH
4 = 16 MPH
5 = 21 MPH
6 = 21 MPH
7 = 21 MPH
8 = 26 MPH
9 = 29 MPH

There’s no point using 9 levels because the 5 level setting includes every available speed increment. Using it on 9 levels is just making it more complicated than it needs to be.

Now I have seen posts about this controller being too powerful on the PAS on level 1, but the wheel only spins the exact same MPH it does on full throttle on those same levels 1/2/3/4/5. I've yet to take it out and ride it yet but everything's working. Like a dozy sod I tightened the crankset back on forgetting to tighten the BB cups so that's the first thing to sort next.
 

AndyBike

Esteemed Pedelecer
Nov 8, 2020
1,474
633
There’s no point using 9 levels because the 5 level setting includes every available speed increment. Using it on 9 levels is just making it more complicated than it needs to be.
For sure. No idea what the manufacturer is coming from there. Must be marketing or such.
My Scott has 4 .eco,tour,emtb(a kind of automatic gearbox) and turbo. I think the assistanse range is Eco - 60%,Tour-170%, emtb 170-340% and Turbo-340%, and im using Tour for the most part,which is offering about 65-70 miles on a 625w battery.
 

Manc44

Pedelecer
Jun 21, 2021
141
24
...im using Tour for the most part,which is offering about 65-70 miles on a 625w battery.
My aim was to always get a 50 mile range and I got a 48V/25Ah (1200Wh) battery, which may or may not be far too big. If it turns out I'm getting even close to your figures, I'll be swapping it out for something 2/3 of the weight. Thing is my fitness levels are bad... which was the whole point of putting a 5KG battery pack on, I know I can hammer it on full blast and not worry about the range. The slightest sniff of an incline and I'm going to be using it.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
21,080
8,616
61
West Sx RH
Now I have seen posts about this controller being too powerful on the PAS on level 1, but the wheel only spins the exact same MPH it does on full throttle on those same levels 1/2/3/4/5. I've yet to take it out and ride it yet but everything's working. Like a dozy sod I tightened the crankset back on forgetting to tighten the BB cups so that's the first thing to sort next.
In PAS 1it's not the speed that folks are concerned about, it's the abrupt full power that provides max torque and acceleration at low speed. For some it is too much and takes them unawares as it's not a gentle nudge from behind but a whacking shove.

Where as with torque simulation controller like the KT it is far different, In PAS 1 only 13% of the rated current is provided. The take off is controlled and relaxed and if one prefers a bit more oomph then PAS 2 is 20% or PAS 3 33% .
 
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Manc44

Pedelecer
Jun 21, 2021
141
24
OK that makes sense cheers Nealh. I think the first thing I'll be swapping out is this controller.

I was almost in tears tonight - I put the whole kit on the bike and got an 08H error. I thought I might have yanked a wire out of a component or snipped through one, in the end it was the 1T4 plug not pushed fully together.
 
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