TongSheng Tsdz screeching noise.

[PeterPi]

I built the bike in 2020 but it's been laid up for almost a year. I rode it for about a mile today and whilst cycling up a slight slope the motor started to make a screeching noise like the gears were not meshing maybe. I freewheeled it down the slope back to home, and as soon as I attempted to pedal** the screeching noise returned.

Does anyone have a clue what is going on? Sounds like it's going to have to be stripped down whatever is amiss.

** an edit: as originally I attempted to "peddle" it, but no one wanted to buy the sound.

TIA Peter

 

[Bikes4two]

I built the bike in 2020 but it's been laid up for almost a year. I rode it for about a mile today and whilst cycling up a slight slope the motor started to make a screeching noise like the gears were not meshing maybe. I freewheeled it down the slope back to home, and as soon as I attempted to peddle the screeching noise returned.

Does anyone have a clue what is going on? Sounds like it's going to have to be stripped down whatever is amiss.

TIA Peter

• Assuiming there's nothin else wrong with the drive train I think a strip-down is inevitable
• On the non-drive side take of the crank arm and then the motor cover to reveal the main gear wheel.
• This area can be prone to water ingress and it's possible that there was minor corrosion going on before you 'parked up' for a year and now the pinion or main gear have suffered further corrosion
• The seal on the drive side (where the motor and 'blue gear are' are better sealed, but whilst you have your tools out, you may as well have a quick inspection.

Let us know how you get on - it's always useful to know what caused the noise.

 

[PeterPi]

• Assuiming there's nothin else wrong with the drive train I think a strip-down is inevitable
• On the non-drive side take of the crank arm and then the motor cover to reveal the main gear wheel.
• This area can be prone to water ingress and it's possible that there was minor corrosion going on before you 'parked up' for a year and now the pinion or main gear have suffered further corrosion
• The seal on the drive side (where the motor and 'blue gear are' are better sealed, but whilst you have your tools out, you may as well have a quick inspection.

Let us know how you get on - it's always useful to know what caused the noise.

Thanks for the swift reply. I'll try to record the sound before I do the dissembly. It might help if/when I post the strip down video.

 

[PeterPi]

This is what it sounds like, but only when I press the left pedal.

Not so much a screech as the sound of someone squeaking one out.

 

[pedalfettal]

This thread might be worth reading...

Pedelecs - Tsdz2 Creaking Noise

 

[PeterPi]

I've done an inspection and partial disassembly but all seems good. Could it be the clutch in the blue nylon gear? Do they fail?

TIA Pete

 

[Bikes4two]

I've done an inspection and partial disassembly but all seems good. Could it be the clutch in the blue nylon gear? Do they fail?

TIA Pete

• I think (and understand why) you are clutching at straws here.
• In that audio clip: how near to the noise source was the recording microphone (just trying to understand the depth/volume of the creaking noise)?
• From a mechanical point of view I've never heard of a Blue Gear bearing failure before but in anycase the creaking sound doesn't really match the noises you'd expect from such a failure.
• The creaking noise itself is more likely the whole motor not being secured adequately either in the bottom bracket or the bridge plate across the chainstay area not siting squarly.
• On this last point (the bridge plate), on one bike that I installed the motor on, the frame tubes were 'lugged' and the bridge plate just overlapped a tip of one of the lugs rather than the plate sitting squarely on the frame tubes, resulting in a creak not unlike yours and under the same circumstances.
• In the pic below you can see an example of lugged tubes. On my bike the 'pointy' bit of the lug was on the top of the tubes (rather than on the side as shown in the pic) and the bridge plate was just catching the tip of one of the lugs. I eventurally filed of the offending tips and all was quiet.
• 

 

[PeterPi]

• I think (and understand why) you are clutching at straws here.
• In that audio clip: how near to the noise source was the recording microphone (just trying to understand the depth/volume of the creaking noise)?
• From a mechanical point of view I've never heard of a Blue Gear bearing failure before but in anycase the creaking sound doesn't really match the noises you'd expect from such a failure.
• The creaking noise itself is more likely the whole motor not being secured adequately either in the bottom bracket or the bridge plate across the chainstay area not siting squarly.
• On this last point (the bridge plate), on one bike that I installed the motor on, the frame tubes were 'lugged' and the bridge plate just overlapped a tip of one of the lugs rather than the plate sitting squarely on the frame tubes, resulting in a creak not unlike yours and under the same circumstances.
• In the pic below you can see an example of lugged tubes. On my bike the 'pointy' bit of the lug was on the top of the tubes (rather than on the side as shown in the pic) and the bridge plate was just catching the tip of one of the lugs. I eventurally filed of the offending tips and all was quiet.
• View attachment 51647

OK, thanks for the heads up. I'm persuaded that I have been looking in the wrong place. At least I've had a look at the insides of the motor, all the better when I really need to strip it down.

Thanks again.
Pete

 

[Bogmonster666]

It isn't the blue gear I am sure, it would not just make a noise on left pedal stroke. I'm with @Bikes4two, that sounds like the motor moving in the BB shell to me.

 

[Bikes4two]

• Bike noises like that can be a devil to find
• On my TSDZ2 I had what seemed like a sprag clutch failure in that on hard peddling the cranks would slip/skip a few teeth in the motor - a classic sprag clutch issue
• There's a YT vid somewhere with a guy stomping on the pedals to demonstrate this and the noise/symptoms matched my own
• So a strip down and sprag clutch change - not a minor task - on reassembly the problem was still there.
• It turned out to be the freehub in the rear wheel! I've never had that issue in tens of thousands of miles of cycling so I was easily persuaded to blame the tsdz2 . Lesson learnt.

 

[PeterPi]

I eventually got around to sorting this out, and there was nothing wrong with the clutch. It was as you, and others have said, a problem with the install. I think there were bolts which had slackened off as upon reassembly all is good.

Thanks for all the input.

 

[Bikes4two]

......... I think there were bolts which had slackened off as upon reassembly all is good.

Thanks for all the input.

That's all good to hear Peter - the cranks need tightening to 40nm and I use a torque wrench to ensure the correct tightness.

The large m33 nut used to hold the motor in place using the supplied spanner also needs to be to 40nm but you can't use a torque wrench for this. Once I've tightend this nut by hand as much as possible, I use a soft mallet to tighten the nut a further 1/4 turn.

 

[AndyBike]

This is what it sounds like, but only when I press the left pedal.

Not so much a screech as the sound of someone squeaking one out.

Yup. arse sounds.

 

[PeterPi]

I was a bit hasty with my assumed fix. Although everything needed tightening up I was unable to a prolonged test of the system until last week. The noise returned when I selected higher gears and I was pedaling quite hard. I changed the blue gear and decided to replace it with a metal one instead. As a result there is no more noise in any gear or on any gradient. I didn't have any lithium grease, so as it's now a metal to metal contact, I used normal automotive lubricating grease. Should I still use white lithium grease anyhow? I've got quite adept at stripping the motor down and reassembling it so it's no hardship to changing the grease.

TIA Peter

 

[saneagle]

I was a bit hasty with my assumed fix. Although everything needed tightening up I was unable to a prolonged test of the system until last week. The noise returned when I selected higher gears and I was pedaling quite hard. I changed the blue gear and decided to replace it with a metal one instead. As a result there is no more noise in any gear or on any gradient. I didn't have any lithium grease, so as it's now a metal to metal contact, I used normal automotive lubricating grease. Should I still use white lithium grease anyhow? I've got quite adept at stripping the motor down and reassembling it so it's no hardship to changing the grease.

TIA Peter

The white grease is for plastic gears. Normal grease is absorbed and expands them, but is correct for metal gears.

 

[PeterPi]

The white grease is for plastic gears. Normal grease is absorbed and expands them, but is correct for metal gears.

Thanks for the info. One thing I have notices is there is a bit more of a whine from the motor, which I assume is now due metal gears that are meshing. I'll put some more grease in there just to be on the safe side.

 

[saneagle]

Thanks for the info. One thing I have notices is there is a bit more of a whine from the motor, which I assume is now due metal gears that are meshing. I'll put some more grease in there just to be on the safe side.

Whine sounds like gears, but more often is the commutation pulses from the controller. You notice it more with motors that have a low reduction ratio - say 5:1 - and it's very much less when you use a sine wave controller. Whatever you have, it should go away as the motor speeds up. When the commutation pulses are a much higher frequency, your ears can't hear the pulses. If your motor wines at high speed, that's unusual.

 

[PeterPi]

Whine sounds like gears, but more often is the commutation pulses from the controller. You notice it more with motors that have a low reduction ratio - say 5:1 - and it's very much less when you use a sine wave controller. Whatever you have, it should go away as the motor speeds up. When the commutation pulses are a much higher frequency, your ears can't hear the pulses. If your motor whines at high speed, that's unusual.

I never thought about the waveform of the three phase supply, but I assume it's modified sine wave, which as you say is more likely to be noticable.

Thanks again.

 

[saneagle]

I never thought about the waveform of the three phase supply, but I assume it's modified sine wave, which as you say is more likely to be noticable.

Thanks again.

Cheap controllers give square wave commutation, which is what causes the wine. One or two of the more expensive ones do sine wave commutation. The former is like knocking the motor around with 20 knocks per rotation (100 per wheel turn), and the latter is more like pushing it round with 100 small pushes.

 

[Terol Jiang]

I built the bike in 2020 but it's been laid up for almost a year. I rode it for about a mile today and whilst cycling up a slight slope the motor started to make a screeching noise like the gears were not meshing maybe. I freewheeled it down the slope back to home, and as soon as I attempted to pedal** the screeching noise returned.

Does anyone have a clue what is going on? Sounds like it's going to have to be stripped down whatever is amiss.

** an edit: as originally I attempted to "peddle" it, but no one wanted to buy the sound.

TIA Peter

The gear has a problem, you need to use a new to replace. the TSDZ2 mid motor gear you need likes this