Pas issue

martinev

martinev

100 W
Joined
Jun 24, 2022
Messages
115
I have a set up matched LCD to controller and I just can't stop the pas going to fast on any selection of settings
I have two set ups one with a s8661 and a sw900 with there matched (purchased as a pair )
but it just speeds away when I increase the pas with any of the settings 1-2-3 etc
any help greatly appreciated
 
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It just speeds up and its not progressive and I have to bring down the pas to level 1 and then that's not enough to power up on pas so I go it to level 20then tat shots off etc etc . 48v 1000watt voilamart hub. this is based on comparing to my Carrera crossfire.
 
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martinev said:
It just speeds up and its not progressive and I have to bring down the pas to level 1 and then that's not enough to power up on pas so I go it to level 20then tat shots off etc etc . 48v 1000watt voilamart hub. this is based on comparing to my Carrera crossfire.
Click to expand...
Are you saying that for every level above 1, PAS make the bike ride at the top speed the bike is capable of? What speed is that?
 
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What speed do you hit in pas level 1?
What speed do you hit in pas level 2?
What speed do you hit in pas level 3?
etc..

Your vague answer above isnt any clearer than the original post.

Your problem description could be interpreted a number of ways, perhaps your controller is speeding you upto max motor rpm in every pas level? OR maybe your controller is accelerating you upto each pas levels speed limit too violently for your comfort.
OR Something else???? Please clarify.
 
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Hi no its not going up to max speed but it increases by to much , yes Fill very fast I have to apply the brak (electric cut out power ) out ,, I am saying start off level 1 in settings (start off -0 ) so select 1 then start off but that's just not strong enough to take off from start so i press + to select 2 while peddling. And it goes tom 8 mph then select 2 goes to 16mph etc . I can have either 3 levels or 5 levels or 9 levels in my settings for (pedal assist ) but I've set it for 3. Maybe its putting to much power into the hub maybe I should adjust the amps its set on 12a
 
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martinev said:
Hi no its not going up to max speed but it increases by to much , yes Fill very fast I have to apply the brak (electric cut out power ) out ,, I am saying start off level 1 in settings (start off -0 ) so select 1 then start off but that's just not strong enough to take off from start so i press + to select 2 while peddling. And it goes tom 8 mph then select 2 goes to 16mph etc . I can have either 3 levels or 5 levels or 9 levels in my settings for (pedal assist ) but I've set it for 3. Maybe its putting to much power into the hub maybe I should adjust the amps its set on 12a
Click to expand...
The controller is using a speed based throttle and PAS. Many controllers use a speed vs power/current control (hence ESC, electronic speed control). With this control scheme, a throttle position or PAS level, equates to a speed, and the controller will provide full power until it reaches that speed. With a power or current control scheme, the throttle position equates to a power or current level, so you can control how quickly or slowly it accelerates, much like the gas pedal in your car. Current/power control is not as common in the cheaper silver box Chinese controllers. I use a Cycle Analyst, so it’s current feedback loop allows it to emulate all three control schemes so you can set the behavior according to your preference. Most programable controllers also allow modifying the behavior as well.
 
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AS said above most silverboxes using cadence sensors for pas input will limit pas levels by speed alone
As you have already reduced your controller to a 12a output limit? from what 20? 22a? and if thats not had a demonstrable effect? i cant see reducing it further would have much impact beyond limiting the speed and oomph you motor will provide to climb.

Perhaps Check out KT (Ketung) controllers which afaik offer the most configurable system at a reasonable-ish cost, but you will also need a compatible kt lcd display too. - this would let you limit the power output in the lower pas levels and you can check out how in any ktlcd manual such as the ktlcd 3 manual.pdf


Why are you relying on pas control, is it a legal requirement in your location? If not i would suggest ignoring pas control and simply fitting and using a twist throttle speed controller, you should find that much more intuitive and natural to ride. fwiw my own 'slightly dodgy' 1000w dinner plate drive bike is only throttle controlled, no pas, and its still a bit of a speed deamon out of the gate, but its manageable..
 
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Hi fill and Ehp
Thank you for you your input .yes E-HP that's exactly what's happening. Fill - I did have a working throttle remove the throttle I was testing pas only.. what's mt best option
 
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martinev said:
Hi fill and Ehp
Thank you for you your input .yes E-HP that's exactly what's happening.
Click to expand...
The Kunteng/KT controllers are affordable and use "torque simulation" which is their name for current based control. The power delivery for both throttle and PAS is pretty good. They aren't programable, but some performance parameters are tunable.
Note: always buy the controller and display as a set to ensure compatibility.
 
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If the throttle works, and allows you to deliver power to the motor for a comfortable ride, i would conclude the experiment with pas was a failure and go back to throttle speed control.

However If the throttle control was just as sharp a start as the pas experience, you may find a KT controller a worthwhile investment? just be mindful some sellers advertise the cheaper Square wave controllers without making the distinction. The square wave controllers work 'ok' but can be a bit clunky/noisy at lower speeds. The slightly more expensive Sine wave controllers are generally preferred.
 
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Ok I want the pas throttle is not me. But I want it to be as my Carrera crossfire bike.
I will look for a KT sine wave controller.thanks
 
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What about people mentioning torque sensor ? Rather than a rotation disc switching on and off there are lots of post about the pas being crap . basically it seems to just switch on and if from the disc single sent from the pedal crank .well that's why it's so aggressive and almost unpredictable.. my wife's halfords 2017 cross fire has a lovely transition when pedalling with pas . How's this achieved. thanks
 
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Not an expert just a bod who will browse the odd ebike ad etc.. but afaik there are torgue sensors and 'torque sensors'.

Real aftermarket Torque sensor options are not really budget, and are few on the ground, this is the only one im aware of available from a uk seller. tho again im not an expert..
bbts.jpg



If the Halfords bike is a top of the range performance machine with a high price its probably fitted with similar, but if a 'standard-ish' bike with a small plastic clip on sensor.. its probably a similar system to the 'power mode' provided by the KT controllers that respond to 'standard' cadence sensor input.. Which works well by all accounts.
 
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martinev said:
What about people mentioning torque sensor ? Rather than a rotation disc switching on and off there are lots of post about the pas being crap . basically it seems to just switch on and if from the disc single sent from the pedal crank .well that's why it's so aggressive and almost unpredictable.. my wife's halfords 2017 cross fire has a lovely transition when pedalling with pas . How's this achieved. thanks
Click to expand...
What is your budget?
 
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Grin has a smoking deal on a torque sensing bottom bracket. You may need to have a Cycle Analyst to get it working OK - or maybe not. I think the torque signal output that matches standard throttle signal voltages. The price us so low that I bought one as a spare. Maybe I'll try it out as a direct throttle input as a test when I get my Iron Horse back on the road.

"This torque sensing bottom bracket operates on the same magnetostrictive property as the THUN / NCTE sensors, which means it measures actual torsion in the spindle and as a result only measures the torque from the left crank. It includes a 18 pole quadrature cadence sensor, and has a wide voltage signal range for the torque measurement, sitting at 0.5-0.6V at rest and rising up above 4V at full torque."

Fischer AG Torque Sensing BB, 127mm

Excellent Deal Bottom Bracket Torque Sensor from Fischer-AG. Senses Left Crank Pedal Force Similar to THUN/NCTE and Requires Drilling Hole in Bottom Bracket for Cable Exit. 127mm Square Taper Spindle and 68mm BB Width.
ebikes.ca ebikes.ca
 
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E-HP said:
What is your budget?
Click to expand...
Depends I have no budget but if It becomes out of balance I will sell the bike I am converting
and keep the Halfords crossfire pic of my conversion white one and the Halfords crossfire bike attached
 

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wturber said:
Grin has a smoking deal on a torque sensing bottom bracket. You may need to have a Cycle Analyst to get it working OK - or maybe not. I think the torque signal output that matches standard throttle signal voltages. The price us so low that I bought one as a spare. Maybe I'll try it out as a direct throttle input when as a test as I get my Iron Horse back on the road.

"This torque sensing bottom bracket operates on the same magnetostrictive property as the THUN / NCTE sensors, which means it measures actual torsion in the spindle and as a result only measures the torque from the left crank. It includes a 18 pole quadrature cadence sensor, and has a wide voltage signal range for the torque measurement, sitting at 0.5-0.6V at rest and rising up above 4V at full torque."

Fischer AG Torque Sensing BB, 127mm

Excellent Deal Bottom Bracket Torque Sensor from Fischer-AG. Senses Left Crank Pedal Force Similar to THUN/NCTE and Requires Drilling Hole in Bottom Bracket for Cable Exit. 127mm Square Taper Spindle and 68mm BB Width.
ebikes.ca ebikes.ca
Click to expand...
Thanks for the heads up
 
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fill said:
Not an expert just a bod who will browse the odd ebike ad etc.. but afaik there are torgue sensors and 'torque sensors'.

Real aftermarket Torque sensor options are not really budget, and are few on the ground, this is the only one im aware of available from a uk seller. tho again im not an expert..
bbts.jpg



If the Halfords bike is a top of the range performance machine with a high price its probably fitted with similar, but if a 'standard-ish' bike with a small plastic clip on sensor.. its probably a similar system to the 'power mode' provided by the KT controllers that respond to 'standard' cadence sensor input.. Which works well by all accounts.
Click to expand...
Thanks fill
 
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martinev said:
Depends I have no budget but if It becomes out of balance I will sell the bike I am converting
and keep the Halfords crossfire pic of my conversion white one and the Halfords crossfire bike attached
Click to expand...
Then I'd get rid of the bike and take advantage of some of the excess inventory deals that are out there on a torque sensing middrive bikes. There's a lot of deals on pricing, and others where they throw in an extra battery, etc. If its for your wife, she deserves one, rather than some hokey conversion that either doesn't perform or looks like a pile of par and wires hanging off a factory ebike frame.

My neighbor bought another Brose motored ebike, since it was a fraction of what he paid for his first one 3 years ago. The torque sensing is impressive (he said better thank Bosche, Specialized, or any of the others he test rode).
 
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martinev said:
Depends I have no budget but if It becomes out of balance I will sell the bike I am converting
and keep the Halfords crossfire pic of my conversion white one and the Halfords crossfire bike attached
Click to expand...
SELL it now dont spend any more on it just refit the throttle and sell to a stranger for food delivery..
Dont sell to a friend or someone you like, if they get pulled over you will feel like crap..

You can get a faster and more torque-y bike with a 250w 36v rated motor and overvolting for an extra 30%power and speed with a 48v battery. And if more power is required you can still apply more amps too :) and all within the regs too so no problem getting insurance or automatically being in the wrong if involved in any accident due to ridding a dodgy bike. Just set the legal speed assist level and your fine.
 
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E-HP said:
Then I'd get rid of the bike and take advantage of some of the excess inventory deals that are out there on a torque sensing middrive bikes. There's a lot of deals on pricing, and others where they throw in an extra battery, etc. If its for your wife, she deserves one, rather than some hokey conversion that either doesn't perform or looks like a pile of par and wires hanging off a factory ebike frame.

My neighbor bought another Brose motored ebike, since it was a fraction of what he paid for his first one 3 years ago. The torque sensing is impressive (he said better thank Bosche, Specialized, or any of the others he test rode).
Click to expand...
There both my bikes, torque sensors are only a few quid , the wires hanging etc are of mid build testing , no the finished bike
 
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martinev said:
There both my bikes, torque sensors are only a few quid , the wires hanging etc are of mid build testing , no the finished bike
Click to expand...
Oop, sorry, mixed up with another thread, or maybe because both your bike and hers are crossfires (cross fires).

I estimate it will cost $250 to $350 US to implement torque sensing PAS on your bike. I have no idea what that is in quid. Note that your other bike doesn't have a torque sensor. It just uses a normal magnetic disc PAS. It's how the controller processes the signal that differs.

You could easily replicate the behavior of your other bike by adding a Cycle Analyst. That will allow you to implement the exact behavior described
"The power control in the system is delivered courtesy of an intuitive cadence sensor, which will adjust the power output based on the users pedalling speed. When the users cadence increases then the system will increase the power output."

You can also program how the PAS or throttle ramps up, and how it ramps back down. The CA can also support torque sensing PAS if you actually need it and want to spend the quid later. If you don't go the CA route, then you will need to swap out your controller.

I still think the KT controller and display will get you what you want, but the CA might do it better, or more closely replicate the Carrera.

I've been working on a PAS section in my FAQ, about a quarter of the way down the page. There's a short list of controllers that support torque sensors. The section above the PAS section has some info on Open Source Firmware, for displays and/or controllers. There are a couple of options there that implement torque sensors, if you're into modding the software and hardware.
endless-sphere.com

DIY Newb FAQ?

I think I've read through all of the stickies in the ebike forums, which provide great guidance. Yet, I see a lot a new folks getting into ebikes and posting questions that are not in the stickies, or are embedded somewhere among the existing stickies. Another observation is there are...
endless-sphere.com endless-sphere.com
 
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Hi E-HP. Great advise and very informative I will continue looking into the options you pointed out and end up with a better understanding so I can make my choice.. as the bike is now it's not a great ride..it's fast when I had the throttle connected . If you like that (40mph) and 1000w hub has plenty of torque ,but it's the pas for me all day long.
 
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