Bike takes off without engaging throttle

[tony234]

Hey gang anybody have there bike take off without throttle engaged? Parked my bike and July son came over and told me my bike took off! It did and dumped a few feet ahead. It will periodically engage without using either assist or throttle!

 

[tomjasz]

If I leave my system turned on and there is any movement where the pedals rotate the PAS will kick in and the bike will seemingly propel itself. I've NEVER experienced any movement with the system turned off.

 

[Sedgeway]

Hey gang anybody have there bike take off without throttle engaged? Parked my bike and July son came over and told me my bike took off! It did and dumped a few feet ahead. It will periodically engage without using either assist or throttle!

Hi I have a bafang mid drive the problem I had was when stopped peddling the motor would keep going until applied brake, the problem located to the Pas sensor board in the motor , required new one but this just a suggestion

 

[tony234]

Hi I have a bafang mid drive the problem I had was when stopped peddling the motor would keep going until applied brake, the problem located to the Pas sensor board in the motor , required new one but this just a suggestion

Thanks for the info!! I will look at all the options. I unplugged the pas and throttle so far no issue after I plugged it back in.

 

[6zfshdb]

I had this happen twice. The problem turned out to be moisture in the throttle cable connector which caused erratic motor behavior. As you experienced, the bike would sometimes take off on it's own.

The fix was to unplug the connector and dry it out with a heat gun or hair drier. The manufacturer sent a repair kit which included heat shrink tubing to keep moisture out of the connector.

As Thomas Jaszewski suggests, as a safety precaution, I've gotten in the habit of turning off the PAS & throttle when dismounting the bike.

 

[harryS]

Had it happen several times.

1) Bike went thru water and throttle connector got wet. Bike ran on its own.

2) Folded another bike for first time and throttle connector gets stretched. One of the three wires came loose. It was the ground wire. Bike took off. Later I found that almost all throttles will do that if the ground wire breaks off or is loose.

 

[Gordon71]

Wouldn't turning off the battery prevent that from happening?

 

[harryS]

It's also why we have brake cutoffs.

 

[rich c]

Sticky freewheel can also cause this kind of event.

 

[tomjasz]

Wouldn't turning off the battery prevent that from happening?

Eggs Ackley!

 

[tony234]

I really appreciate everybody’s input I’m gonna mess around with that today see if there’s any wet throttle issues happening!I’ve disconnected all the PAS and throttle connections both at the controller and from the throttle to the connector going to the controller! I will also look for moisture!! Shutting the bike off is definitely a habit I’m going to get into all the time but I feel for customers who may not have this knowledge and that damn bike takes off where other people are around...

 

[tony234]

Sticky freewheel can also cause this kind of event.

The issue is also while riding it goes full throttle so that only works when it’s parked now I do it all the time even after I fix it I will just in case........

 

[6zfshdb]

Often, there isn't any visible moisture in the connector. Use a heat gun or hair drier on it anyway to be sure. It doesn't take much to cause problems.

 

[tony234]

Ok! I have removed both pas and throttle connections to try drying! Thanks for the info!!!

 

[tomjasz]

Get some Boeshield or ACF50 once sorted and treat each connection. This will provide protection from water and moisture issues.

 

[tony234]

I absolutely will do this!! I think it was my PAS cables. Unhooked from the controller and took off from the bike. Just using the throttle it seems to be working fine. I will continue to test and then if it is resolved look for a new pas sensor! Thank you for all the help everyone!’ Fingers crossed!!

 

[tony234]

I think it was my pedal assist I found one on eBay and another one on Amazon I think they’re the same thing!!

 

[Onostiff84]

It's also why we have brake cutoffs.

A wire on same harness could cause it happen

 

[PCeBiker]

I had this happen twice. The problem turned out to be moisture in the throttle cable connector which caused erratic motor behavior. As you experienced, the bike would sometimes take off on it's own.

The fix was to unplug the connector and dry it out with a heat gun or hair drier. The manufacturer sent a repair kit which included heat shrink tubing to keep moisture out of the connector.

As Thomas Jaszewski suggests, as a safety precaution, I've gotten in the habit of turning off the PAS & throttle when dismounting the bike.

Had it happen several times.

1) Bike went thru water and throttle connector got wet. Bike ran on its own.

2) Folded another bike for first time and throttle connector gets stretched. One of the three wires came loose. It was the ground wire. Bike took off.

Later I found that almost all throttles will do that if the ground wire breaks off or is loose.

I did a bunch of research and testing on e-bike throttles and found that All my Hal sensor throttles behaved the same way, but a proper motor speed controller using the right resistors and potentiometer doesn't do it.

I followed @6zfshdb 's throttle schematics,..

Adding a Rotary Dial Speed Control

I occasionally get a cramp in my right hand when using my half grip twist throttle. As a remedy, I built this small control box as an alternate way to adjust speed. In doing some research, I discovered a 3 wire hall effect throttle can be emulated with a variable resistor. I wired the control...

forums.electricbikereview.com

,.. and the basic throttle information and the "Speed Set" or "Throttle" parameters found on Every type of controller stating that throttle voltage ranges from ~1v to ~4v ,..

My first hub motor e-bike has a proprietary throttle with the connector plugs reversed.
It turned out that the voltage was also reversed, in that the throttle output is ~1V at full throttle and ~4V at zero throttle.

Das Kit Switch Throttle Pinout

Does anyone know the pinout for the Das Kit switch throttle? Specifically, I know which pin is +5V, but I don't know which pin is signal and which pin is ground. I cant' find the diagram online. I tried to switch to a Bafang half twist throttle, but it didn't work so I'm thinking Banfang...

forums.electricbikereview.com

When the ground wire is disconnected on my Das-Kit throttle, the throttle goes to zero instead of full throttle.

And I found out that the reversed throttle is for a mid-drive motor and Das-Kit just adjusted their software to work with it.

It's a much safer design to go to zero throttle when the ground is disconnected.



With a proper Speed Controller, the voltage goes to 5V when the ground is disconnected, and that triggers a fault in the controller to shut off the power.
Or with a mid-drive throttle, the voltage goes to 0V which also triggers a fault in the controller



The voltage SHOULD go to zero or 5 volts when the ground is disconnected, not 1 volt or 4 volts.

The Entire built-in safety of a 1-4 volt throttle input is negated with a Hal sensor throttle.

And there's No Damn reason why they can't redesign the Hal sensor circuit so it goes to 5 volts with no ground.

The throttle is being fed 5 volts.
It should put out 5 volts with no ground.

1) Bike went thru water and throttle connector got wet. Bike ran on its own.

Water could still affect the throttle and make it go, but if they used a mid-drive type throttle on a hub motor (like my hub drive Et.Cycle with a Das-Kit throttle), then the ebike would probably slow down when it got wet not power up ?

 

[6zfshdb]

I've found that different controllers (and throttles) react differently to erroneous HAL signals. Most resistors aren't affected substantially by water, that's why you don't get the same behavior.

I'm not really sure why bike makers don't use variable resistance in throttles instead of the HAL effect. You get the same result but with a lower risk of failure. Cost maybe?