Pedal assist on Bafang BBS01 - 02, is it real pedal assist?

Wolf66

New Member
Hi everyone,

So I currently have a cheap chinese ebike with throttle and "PAS". The throttle is working fine, however PAS on this bike doesnt really feel like pedal assist and it feels more like a second way to activate the motor at a set speed limit. So as soon as i start pedal, it pushes me really hard as if it was another way to go with throttle, you know this is not real IDEAL Pedal Assist like Bosch Brose systems. So it is pointless to use this "Pedal assist" and i just use soft throttle, the acceleration for pedal assist on this bike is too fast too aggressive.
For this reason im considering a DIY ebike as an option for my next ebike using this bafang kits, however the only thing im not sure is if this is real pedal assist like PAS 1 gives me 50 watts support, pas 2 gives me 100-150 watts, etc etc, and not just activate full motor power up to the top speed limit for each level which is how it works in my cheap bike.
I believe that with a good PAS system, i will be able to dramatically increase my range as opposed to going full throttle all the way without the option to pedal assist and save battery.

I also found out that Rad powerbikes have true pedal assist on top of the throttle compared to my 48v ebike were pas is literally useless and is only usable for its throttle. I know that Rad powerbikes use a good Chinese quality ebike system but im wondering if Bafang 8fun DIY kits also have this same technology of advanced pedal assist.

So do you guys know if Bafang kits do have advanced pedal assist?
If so what kind of range should i expect with PAS, would it be similar to Rad powerbikes range estimates if i were to go with 750w bbs02 48v 14ah battery? what if i go with a 350w motor?

I havent been able to find other range tests from 48v systems using various Pedal assists to give me an idea, only from rad bikes tests i could get some idea, but if you know anything about the bafang pas, please let me know!
 

dAz63

Member
The BBSxx motors use cadence sensing, it senses your pedaling which activates the motor to whatever level assist you have set it to, yes you can ghost pedal where you can pedal with no effort, no a bad idea it you have bad knees for example of like a friend of mine where the left crank fell off, he was able to move the right pedal back and forth to activate the motor to get home.

Then you have torque sensing which the Bafang Ultra motors use and the same on Bosch, Brose, Yamaha and Shimano motors, these sense the pressure on the pedal which turn the motor on to the level set by the assist and pressure from your foot, so if you are cycling along on the flat with little effort then the motor is not drawing much power, but you come to a rise or suddenly need to sprint through an intersection then the motor will immediately respond with more power.
 

harryS

Well-Known Member
If you think the RAD's work for you, I think you will find the Bafang BBS02 to be similar. Mine came default with only a overpowered 3 level PAS, but that can be changed in setup to a 9 level system, where each level has a maximum speed. If you ride below that max, you can ghost pedal with no effort with the cadence acting as an on/off switch. If you ride above it, then it feels like you have pedal input. With a programming cable, one can adjust the power delivery at each PAS level, but I never cared to do so.

I am not saying that a bicycling purist will like the cadence system. I've installed some controllers with awful cadence systems that I just took and never used. Still, I've owned over a half dozen ebikes with cadence systems and am used to them.

As for range, that depends on speed.
 

Wolf66

New Member
If you think the RAD's work for you, I think you will find the Bafang BBS02 to be similar. Mine came default with only a overpowered 3 level PAS, but that can be changed in setup to a 9 level system, where each level has a maximum speed. If you ride below that max, you can ghost pedal with no effort with the cadence acting as an on/off switch. If you ride above it, then it feels like you have pedal input. With a programming cable, one can adjust the power delivery at each PAS level, but I never cared to do so.

Im not sure I understood..
so would that be programming controlling the speed limit for each 9 pedal assist levels?
because if thats the case then the motor is still providing 750w power until it reaches a set speed limit based on pedal assist level.
For example at level 1 pas, it will be 8mph top speed however the motor still accelerates like a beast because we are not controlling the motor output power, only the speed limit for each level.
When this happens, PAS 1 still feels like an aggressive acceleration and thats not what happens with the Rads. With a rad bike PAS 1 makes the bike as if it never came with a 750w motor because it forces the motor to provide like 10% of its nominal 750w without affecting top speed which is 20mph, this combined with cadence torque sensing, allows the bike to accelerate in a more natural way like in the Bosch bikes. This means you can reach 20mph on pas 1 with only 50 watts of assistance as opposed to set 10 mph speed limit but the motor still accelerates with 750w mad power and continues until it reaches 10 mph, which you will then need to pedal more if you wanted to reach 20mph.
 

WilliamT

Active Member
It sounds like that system was mainly designed for throttle only and the PAS was an after thought.

It's probably programmed to run 100% of the power until each level's speed is reached.

My experience with RAD is that each level runs at a fixed percentage of the total battery watts. As you get closer to the max speed for that level, the assist slowly lowers until you reach zero.

With my BBS02 and BBSHD units, the level of assist runs at a fixed percentage of the max power similar to RAD. The only difference I notice is that it doesn't die down based on speed.

Other units, like my Bafang geared hub (G020.500.D), provide PAS assist based on speed. If I slow down my speed, the assist increases gradually to help you maintain a constant speed. Once you reached the level of assist top speed, the assist goes to zero. This works great when your climbing. If I can't pedal as fast uphill, the assist gives me the difference that I need. On flats, it saves battery life as I maintain my speed on my own with no drag from the unit. My usage goes from 12 watt/mile to 6 watts/mile.

Knowing the total watts available from the battery (amps x voltage), you can divide by the average watt/mile (rule of thumb is 20) to estimate the range.
 
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harryS

Well-Known Member
The BBS01-BBS02-BBSHD use the movement of the pedals as an on/off switch just like the RAD that you rode, and also your current e-bike. There are no cadence systems, as far as I know, that actually care about how fast or how hard you press the pedals.

Some cadence systems set a current limit for the motor in the lower assist levels. If you can pedal at this upper limit, then the pedaling feels more natural with you and the motor sharing the load. By default, it's like a speed limit, but with a mid drive that speed depends on the gears used. On a hub motor where the gearing is fixed, it is a real speed. Pedal harder and the motor keeps spinning, but no faster. The extra speed comes from you.

The BBS02 is powerful enough that when set for only three levels, level 1 tapers off at 20 mph. With 9 levels, that level tapers off around 13-14 mph, and this depends on your gearing. There is further user adjustment on the BBS where one can adjust the current in each level. Never had the desire to do that. Requires a PC amd a programming cable.

I don't consider my BBS02 very sophisticated. Mine came programmed from the seller to have throttle always active. RIde it with PAS turned off and feather in throttle as needed. That's probably the most natural. Ride it in PAS 3 if tired. You can cruise around 16 mph and if you become untired, you can pedal a little harder and go faster.
 

Thomas Jaszewski

Well-Known Member
I have some files, 28 or so of .el, BBSxx programming files but can't seem to upload them. Message me with an email address and I'll share them.
 

Richard JM

New Member
Hi all, I ride a BBSO2 500w, 36v this is the second Bafang motor I have owned the first was a 250 w it did not have the power I wanted for off road riding, the 500 is good it will keep up with the more expensive bikes, no problem! Because I ride with two different groups I need different power settings to suit the different riding styles, because of this I use 9 power settings, this gives me a bigger rang of different settings ,I use my USB cable (specialy made for the job ) plug in my computer go to settings and adjust my power settings to suit my needs.the object is to be able to peddle constantly at the seed we are cruising at with out over powering or under powering ! You can get all the information you need on utube .
Hope this helps Richard.
 

Erdbeeren

New Member
Hi, just looking for some clarification regarding the lower levels of assist with the BBS02. Will the motor provide a lower level if assist up to the max top speed? Or do the lower levels have the motor cut out at a lower top speed?