E motor engages without touching throttle

[Gee]

Was gifted a gently used pedal assist e-bike……my first. When I turn on the key and start to pedal, the motor engages (in turbo mode!) without me touching the handlebar grip throttle. Thoughts?

 

[Django]

Please add some details, (make, model, year….).

 

[Gee]

I’m sure this is not a good sign, but there is no brand name (make/model) anywhere on the bike. There is a serial number stamped on the front of the frame. The bike appears to be in really good condition and when just pedaling tracks perfectly straight. But when I turn the key to on and begin pedaling, the motor engages unexpectedly (since I don’t have my hand on the throttle).
what can I do to adjust this?

 

[Django]

I’m sure this is not a good sign, but there is no brand name (make/model) anywhere on the bike. There is a serial number stamped on the front of the frame. The bike appears to be in really good condition and when just pedaling tracks perfectly straight. But when I turn the key to on and begin pedaling, the motor engages unexpectedly (since I don’t have my hand on the throttle).
what can I do to adjust this?

Posting some pictures might help someone to identify it. Does the motor, battery or any component have any identification?

 

[Gee]

Please add some details, (make, model, year….).

Thanks for responding! No brand or model identification anywhere on the bike. There is a serial number. The bike appears to be “as new” condition and is a joy to ride when just pedaling. But when I turn on the key to motor and begin pedaling, the motor engages at a high rate of speed without me even touching the throttle control.

 

[Django]

I suppose that it could be a defective throttle. Some throttles are easily disconnected, (unplugged). I would try disconnecting the throttle first.

Does the motor input stop when braking or when shifting?

 

[HumanPerson]

No markings on the hub motor?

 

[Gee]

I suppose that it could be a defective throttle. Some throttles are easily disconnected, (unplugged). I would try disconnecting the throttle first.

Does the motor input stop when braking or when shifting?

The motor input stops when I stop pedaling. If I keep pedaling, no matter how fast or slowly I pedal, the motor keeps producing a high rate of output. If I stop pedaling, I just coast.

 

[Videolester]

Isn't that the way a pedal assist system is supposed to work?

 

[Osgood71]

Sounds like it is working as designed.

 

[ERidesOn2]

I guess we can rule out it being a torque sensing mid drive system, with levels of assist. I'd try what the gentleman above suggested, taking a closer look at the throttle. Otherwise it might just be a poor design. There's plenty of them out there. Good luck!

 

[Freddy1]

Isn't that the way a pedal assist system is supposed to work?

My thoughts exactly. Without any details, what is the PAS level setting on the display? If its a KT type display and set to "5" (maximum) what its doing is exactly what its supposed to do, apply full power when you start pedaling.

Also check the C1 programming setting if it is a KT type display.

 

[Osgood71]

That's exactly the way my bike works, and it is supposed to work that way.
There are 2 ways to engage the motor. Either begin pedaling, or press the thumb throttle switch.
The only reason to use the throttle is to engage the motor and make the bike go without pedaling.
As long as your PAS is turned on any level, the motor will engage to assist you even if you don't use the throttle to engage the motor.

 

[Hoggdoc]

I’m sure this is not a good sign, but there is no brand name (make/model) anywhere on the bike. There is a serial number stamped on the front of the frame. The bike appears to be in really good condition and when just pedaling tracks perfectly straight. But when I turn the key to on and begin pedaling, the motor engages unexpectedly (since I don’t have my hand on the throttle).
what can I do to adjust this?

As Osgood71 said it is suppose to do that it's called cadence sensing Pedal Assist. Do you have some sort of control pad on the handlebars that would allow you to change the Pedal Assist levels?

You have bee asked for pictures before, provide pictures of the handle bars and all attached to them. Also detailed pictures from both sides of the pedal/crank area. More shot of the front and rear wheel areas focusing on the hubs and brake areas.

Without these pictures I seriously doubt anyone here can be of any assistance. Possibly you can find a store in your area that sells and repairs ebikes they maybe be able to help you figure out how to operate this bike.

 

[knightrider]

I have 4 bafang mid drive units. One of them will accelerate briefly when you first turn unit on and move the cranks about 1/4 round. This happens even if the pas is not selected. Will do this upon start up everytime. Always has since I got the unit from Luna. Only one of 4 that does this.





Also have 3 aventon hubs and nar one of them does this. I think it is a glitch in programming or controller. Who knows. It is what it is. Electrical and Mech. things sometime have a mind of their own it seems.