Dual Sport+ Issue When Standing

[Drozdster]

My wife just bought the Dual Sport+ and I have the Specialize Vado SL. We both are very fit and hardly ever use the motor unless we are tired and going up a hill. She loves everything about it but one thing. As she stands up to pedal on a hill we both noticed a loud clicking sound and the cadence didn't look smooth. I thought maybe a loose bottom bracket.

I checked the bottom bracket and all felt tight. So I took it for a ride up a hill standing and putting a lot of pressure on the pedals and felt something I never felt before in all my 50 years of riding. It seemed like when your foot got to the top of the stroke, it wanted to go back ever so slightly, and than go forward, which gave it a "jerky" motion. Did this with no power and "1" power. I didn't need to increase the power level anymore because it seemed like it did this only when put under some force.

It did it both ways. Clipped and unclipped. Didn't seem to make a difference.

It wasn't always consistent, but when it happened it was very annoying. It is very hard to explain because I never felt anything like it.

Anyone ever get a feeling like this on ANY bike? Something I am not aware of?

 

[Stefan Mikes]

My wife just bought the Dual Sport+ and I have the Specialize Vado SL. We both are very fit and hardly ever use the motor unless we are tired and going up a hill. She loves everything about it but one thing. As she stands up to pedal on a hill we both noticed a loud clicking sound and the cadence didn't look smooth. I thought maybe a loose bottom bracket.

I checked the bottom bracket and all felt tight. So I took it for a ride up a hill standing and putting a lot of pressure on the pedals and felt something I never felt before in all my 50 years of riding. It seemed like when your foot got to the top of the stroke, it wanted to go back ever so slightly, and than go forward, which gave it a "jerky" motion. Did this with no power and "1" power. I didn't need to increase the power level anymore because it seemed like it did this only when put under some force.

It did it both ways. Clipped and unclipped. Didn't seem to make a difference.

It wasn't always consistent, but when it happened it was very annoying. It is very hard to explain because I never felt anything like it.

Anyone ever get a feeling like this on ANY bike? Something I am not aware of?

Sorry to hear about your issues! I cannot explain the phenomenon right now so only let me tell you I have never needed to pedal standing on an e-bike to climb... I understand you have no issues with your Vado SL? (Just let me tell you the Dual Sport+ as a hub-drive low power e-bike is not an ideal climber...)

What could be the cadence of your wife uphill? Very low?

 

[PedalUma]

I had something similar to this two days ago. It was the needle bearings inside a nylon step-down 'blue' gear. I replaced all the bearings in the motor and repacked the grease including the main gear. Now it is super quiet and smooth. I also replaced the $65 bare motor while it was open. Why not? On rereading OP it could be a broken tooth on the main gear at top-dead-center. Is it still under warranty?

 

[Drozdster]

Sorry to hear about your issues! I cannot explain the phenomenon right now so only let me tell you I have never needed to pedal standing on an e-bike to climb... I understand you have no issues with your Vado SL? (Just let me tell you the Dual Sport+ as a hub-drive low power e-bike is not an ideal climber...)

What could be the cadence of your wife uphill? Very low?

We just both like to stand going up hills to change body position and relieve some muscles while activating others. Kind of like sitting, than standing at your desk.

She had the SL originally but for her, the Trek feels smoother when engaging and more than enough power. She has it on 1 mostly, occasionally seeing 2. It is pretty hilly here in CT where we ride.

And yes, her cadence does reduce while standing, as does mine, but it just feels good to get out of the saddle.

 

[Drozdster]

I had something similar to this two days ago. It was the needle bearings inside a nylon step-down 'blue' gear. I replaced all the bearings in the motor and repacked the grease including the main gear. Now it is super quiet and smooth. I also replaced the $65 bare motor while it was open. Why not? On rereading OP it could be a broken tooth on the main gear at top-dead-center. Is it still under warranty?

This is interesting, I guess it is possible. Yes it is still under warranty as it is a week or 2 old. Noticed the problem on our first ride, paid a little more attention to it on our second outing. It is just going to be hard to explain it to the LBS and it will be hard to duplicate because there are no big hills near the LBS when I bring it in.

Maybe I have never felt it on any other bike I have had because this is the first with a rear motor. Not sure if it is common problem with rear drive and others don't notice it because they don't stand on hills?

 

[Stefan Mikes]

And yes, her cadence does reduce while standing, as does mine, but it just feels good to get out of the saddle.

I ride standing on the pedals while riding on the flat pretty often. Not pedalling.
My guess was slow cadence of your wife combined with the burst on pedal strokes could make the cadence sensor be switching the motor off and on during the climb.

 

[Drozdster]

Good point, but I did try it with the motor off and felt the same effect. I will experiment more to try and narrow it down.. And actually this bike has a torque sensor.

 

[Stefan Mikes]

And actually this bike has a torque sensor.

Users report that torque sensor just works on the on/off principle...

 

[Drozdster]

Thanks for the input. I kind of sensed the same thing myself but just thought it was me. But my wife likes the feeling and that is all that matters. LOL

 

[PedalUma]

Oh, it is a rear motor. Without a photo and context I assumed a mid. Then it is likely the cadence sensor. Funny thing, there was a rear motor cadence sensor bike that was bucking like a wild horse. It turned out that half of the magnets on the cadence wheel were in the wrong polarization.

 

[Drozdster]

So I went to my LBS and he had the answer. The cadence not being "smooth" happened all the time after I experimented more. There seemed to be a lag. The LBS told me that the rear hub only had 3 pawls so it didn't catch immediately when pedaling. Made sense to me.