BBS01 brake cutout working on throttle, not on PAS

Here's a weird one. I've nearly finished my BBS01 install and I've used brake sensors for hydraulic brake levers. When I use the throttle the brake cutouts work fine, but not when using PAS. If I'm turning the crank (the bike's up on a stand ) I can pull the brake lever and the motor continues to fight against the brake. The sensors are obviously working fine as when using throttle and touching the brake the motor cuts out instantaneously.

Has anybody else seen this behaviour? It's not something that can be adjusted in the programming as far as I'm aware (I have a cable I can use if necessary).

Michael

mfj197 said:

Here's a weird one. I've nearly finished my BBS01 install and I've used brake sensors for hydraulic brake levers. When I use the throttle the brake cutouts work fine, but not when using PAS. If I'm turning the crank (the bike's up on a stand ) I can pull the brake lever and the motor continues to fight against the brake. The sensors are obviously working fine as when using throttle and touching the brake the motor cuts out instantaneously.

Has anybody else seen this behaviour? It's not something that can be adjusted in the programming as far as I'm aware (I have a cable I can use if necessary).

Michael

Click to expand...

Nobody else experienced this?

I've never had this issue. I pull the lever, the motor seems to cut? Kinda hard to test on a stand, but quite often I will squeeze the brake when manoveuring round pedestrian crossing buttons and the motor definitely cuts and doesn't force against it? I have disconnected my throttle... not sure if it makes a difference

Thanks Lurkin, that's just the sort of reply I needed. It is difficult to test on a stand unless it's the front brake you pull whilst turning the cranks. I thought that the brake cutouts should prevent the motor kicking in when pedalling, but mine doesn't behave that way. I'm a bit concerned for exactly the sort of scenario you mention - coming up to obstacles, roundabouts, crossings, turnings, people, congested traffic. I need to be able to move (pedalling) without being shot forwards into oncoming traffic! Yes I can reduce the assistance level, but I shouldn't need to do this for every single junction!

Michael

Edit: I might try disconnecting my throttle too to see if the situation changes.

Have a look through the programming thread, where all the changeable parameters are listed. Maybe there's one for the way the brake switch works.

d8veh said:

Have a look through the programming thread, where all the changeable parameters are listed. Maybe there's one for the way the brake switch works.

Click to expand...

Thanks d8veh. I've pored over that thread but to no avail, and have read the programming of my own controller and nothing seems awry. The only funny is the controller reports a firmware version I haven't seen reported anywhere before.

Michael

Hmm had a bit of a play on max assist on the way home tonight.

I have hydraulic brakes with sensors as well btw.

Definitely cuts assist as when I'm pedaling with the brake on it does nothing. However, take the brake off in a low (easy pedal) gear, it bucks forward and wants to go!.

Its definitely sensitive though. I have a decent gap between on and off because my brakes are in need of a bleed (new pads on order). I am also using a different magnet, as the original washer went missing during testing. I am using a flash tiny little neodymium magnet (its actually a replacement for a spoke magnet for a speedo for road bikes) which I've snuck onto the end of the inner edge of the brake lever. Magnet is so strong theres no need for glue or anything- its actually pretty hard to get out! Just got to work out a nice way to mount the sensor and it should end up looking profesh.

I'd be testing that first than programming. I know I had to fiddle with mine to get the positioning right. I found the distance testing was more important than magnet type/strength (no, getting a really powerful magnet isn't the answer, I just used what was at hand) I.e. get it on a stand with the throttle plugged in and work out the minimum squeeze before it cuts the throttle. Then see if you can do the same with pedal assist with the throttle plugged in... then without.

I am wondering if there is some treatment thats different due to stand awkwardness. Maybe go to a quiet, flat xarpark/industrial zone for safe physical testing?

Can also use a rubber band to hold the brake on for testing- more hands to operate other things.

Get it working correctly. Turning down the assist is not a solution, your more likely to have an accident whilst mucking about and being distracted by it.

Lurkin, I do appreciate you trying it out and confirming the behaviour I'm seeing isn't normal. I completely agree, I really don't want to be messing around with power levels every time I come up to a junction with any traffic. Besides, I'm riding in my old motorcycle gauntlets through the winter here and I very much doubt I'd have the dexterity to press the controller buttons easily!

I actually tested it last night with an original brake lever with cutoff rather than the hydraulic sensor cutoffs I have mounted, just to completely put to bed the notion that it was the brake sensors. Exactly the same behaviour - motor cuts off when using throttle but doesn't when pedalling. It's pretty easy to test up on the stand as I just spin the cranks whilst holding the front brake on, or last night whilst holding the original brake lever engaged in my hand!

As I mention above I connected the programming cable and read the controller - nothing gives any indication of affecting the PAS motor cutoff. The only thing I noticed is mine has a firmware version which I haven't seen anywhere else - "V2.A.M.t" . I wonder if this custom firmware is the culprit?

Get it working correctly. Turning down the assist is not a solution, your more likely to have an accident whilst mucking about and being distracted by it.

Click to expand...

So true.

Michael

And now it gets even more weird when I try riding the bike. Pulling either brake lever causes the BBS01 to stop reading the speed sensor, resulting in the displayed speed dropping to 0 (even when still moving along). Worse than that, if I pull the brake continuously for a short while whilst pedalling the display flags up Error 21, which is the speed sensor error. Indeed if I put the bike up on the stand and turn the cranks the speed sensor does its normal thing of flashing once per wheel revolution, but when I pull either brake lever it stops flashing.

I'm not so sure it's just a firmware issue now. Maybe there's some dodgy wiring in there.

Michael

Pretty weird and beyond me. Mine came with a loom which could only plug into the correct items... no drama at all there. Perhaps get a multimeter and workout what is going where, per wire/pin. Then verify if it's meant to go there. In any case
, could cut down the potential problems with wiring.

Definitely weird, and mine came with the standard loom too. The brakes are of course on a different cable altogether from the speed sensor, so if it's messed up wiring it will be inside the motor. I've emailed the company I bought it from as it will need to go back if it can't be resolved.

Thanks for your help Lurkin.

Michael

Just to finally update and close this one, it was actually the hydraulic brake sensors that were faulty. My supplier took my motor back and was able to recreate the problem using an early brake sensor identical to the ones they had sent me. They then tried it with a later version of the sensor and it worked fine, cutting power under PAS. The later versions look identical. They have sent the motor back together with a pair of the working sensors and all is well.

I had checked the brake sensors by unplugging one of the early hydraulic ones and plugging in the brake lever which came with the kit - it too didn't work. However the other hydraulic brake sensor was still plugged in to the loom and I guess that was what caused the original brake lever not to work.

Michael

Well done!

- Build thread!
- Spreadsheet of KMs!

I'll put up a build thread soon. What's a KM?

Michael

FWIW, I wonder what actually caused the problem? I doubt it was just the brake sensor, regardless of what they said.

It makes no sense that it could be the sensor, because the sensor worked: it allowed the controller to detect brake lever engagement, and that's all that should matter.

After the sensor is detected "on" by the controller, then it would process that for both the PAS *and* the throttle usage based on it's programming (factory or user, whichever applies).

Since it *did* work for throttle but not for PAS, the sensors worked, but the controller did not do the same reaction output for both speed command inputs.

That says that it was a problem within the controller itself somewhere, either hardware or a setting.

My guess is that they actually just changed settings, or swapped out the controller, to fix the problem. They may have *also* changed the brake sensors, but those should not make a difference to the problem itself.


It would have to be a very strange design of controller to have the sensor be the problem, since it did actually work (just not on both).

I'm not the only person who has had this problem with the brake sensors. One of the users on the UK Pedelecs forum where I am a member had exactly the same symptoms, with the same sensors bought from the same supplier. To use his words in this post "my original setup did work when the thumb throttle was in use, but not when the bike was being pedalled". He resolved his issues by reverting to the brake sensors provided with the kit.

As I understand it these sensors are not just a switch, they are a hall effect sensor. I guess it could have been drawing too much current from the controller, there may have been capacitance / inductance issues, incorrect pull up/pull down resistor or whatever. The fact that the speed sensor stopped being read when the brake was pulled may suggest a short to ground of the feed supply when the switch was activated or something like that, as I guess both the speed sensor and the brake sensors are fed from the same 5V supply.

I still have the original faulty sensors so could test them again, although I've removed the throttle from the bike and weatherproofed the blank plug on the loom so don't really want to plug it in again!

Michael