TQ motor

[AntonioAlfaro]

Grinding Noise

What seemed perfect ceased to be so. My odometer has crossed the 1000 km mark, and in the last three rides, a terrifying noise started coming from the TQ50 motor of my 2023 Domane+ SLR. For a moment, I thought some mechanism inside the engine was being ground because it was an abnormal noise I had never heard before. After my initial terror subsided a bit and and thinking about my return home, I began to notice that this deafening noise occurred under certain circumstances, but most of the time or when the motor was in OFF mode, it did not happen. I found that the grinding noise was correlated with my cadence, the power from both me and the motor, and the rear gear ratio. The noise didn't occur when I was climbing a hill, applying power to the pedals. It happens when you're on a flat slope, stop pedaling for a moment, and then start rolling again. When you begin pedaling again, there seems to be a kind of desynchronization between the motor and the pedal axle, and the grinding noise appears. It's as if there are unsuccessful attempts to engage the motor with the transmission axle. During these moments, I observe that I'm delivering some power, I'm over-rotating, and the motor is delivering very little power (no more than about 10W). However, if I shift to a higher gear, reducing rotation and increasing the power delivered by the motor, the noise disappears completely. As long as the motor is delivering enough power (more than 30W, I'd say), the dreadful grinding noise doesn't occur.

Is this an intrinsic characteristic of the TQ50 motor? Is it a design flaw? Is it a software issue with motor control? Is it normal and should one simply avoid the conditions in which it occurs?

I'd like to know if anyone in this forum is experiencing the same noise.

 

[Stefan Mikes]

I cannot say anything about the TQ50 motor behaviour Antonio. I only noticed the Specialized SL 1.1 motor hates to be delivering too little power. If the SL motor delivers more than 30 W (as it is in your case), the motor appears to be working normally. If it is OFF, no noise. However, in the very low assistance region, the SL motor emits grinding noise (as if it was starting and stopping its operation). The same might be the case of your TQ50 motor.

 

[AntonioAlfaro]

Thank you, Stefan, for sharing your observation related to the Specialized SL. It seems to be a similar behavior. How have you resolved it in your case?

 

[Stefan Mikes]

Thank you, Stefan, for sharing your observation related to the Specialized SL. It seems to be a similar behavior. How have you resolved it in your case?

I have realised that the motor has its operational limits and will not work properly at a very low assistance demand. For instance, asking the motor to work at 15% assistance (it is the rider times 0.27) with my typical leg power up to 100 W demands the motor to provide 27 W or less, which the motor cannot deliver. When I pedal stronger, the motor gets into its normal operational regime. Additionally, the SL motor has the "max motor power cap". If that is also 15%, the 240 W mechanical motor power is capped at 36 W. With the 15/15% assistance, the motor is constantly in the transition zone between the non-operational and operational state, making the grinding noise.

I am well off by setting the assistance to 30/60% (it is the rider power times 0.54 with the motor power capped at 144 W). With such a setting, the motor is in the operational regime at all times. If I need less assistance than that, I simply put the motor in the OFF state and am pedalling on my own leg power.

 

[AntonioAlfaro]

Thank you, Stefan. I understand what you're saying, and I find it very valid. What generally catches my attention is that if, indeed, at low assistance demand the motor doesn't perform well, why don't they restrict those configuration zones via software?

 

[Stefan Mikes]

Thank you, Stefan. I understand what you're saying, and I find it very valid. What generally catches my attention is that if, indeed, at low assistance demand the motor doesn't perform well, why don't they restrict those configuration zones via software?

No reason. The motor goes on and off to meet your desired assistance demand and you'd probably figure it out yourself it was not the correct way to operate the e-bike motor. I do not think you could damage the motor that way. For one, the default ECO assistance on SL 1.1 motors is 35/35% (well within the operating range of the motor).

Also, fancy a strong rider on an SL e-bike. The person would input 200 W at the 15% assistance: the assistance demand would be 54 W, again well in the motor operating range. I only wonder why a 200 W rider would need an e-bike in the first place...

 

[AntonioAlfaro]

Searching a bit in various forums, especially in MTB forums that use the TQ50 motor, I come across the fact that this same issue is well-known to them, and they have even received a response from the manufacturer clarifying their stance. I am attaching a YouTube link where I found the following response from TQ:

"@RobRidesEMTB
To add - the motors are near silent on descents - barely any noticeable rattles (especially compared with Shimano / Bosch)Also, TQ responded to a small number users experiencing noises. Here’s what they said:

Hey Rob! Just wanted to give you a quick heads up regarding the noise discussionsWe are currently working on this topic. It has no influence on the motor’s performance or durability and seams to be no more than a peculiarity of one of the sprag clutches of our motor. If the motor’s assist is very low (less than ~ 10W) it seams that the electric motors torque is not enough to rotate the clutch, but not fully engage it. This can lead to the weird rattling/grinding noise. The forces in such a scenario are however extremely low and do not put any mentionable wear on the internals of the motor. From everything we know and all the 1000s of field testing kilometers we have already done this issue is nothing to worry about. Nevertheless the low noise is one of our strongest USPs and we are working on a solution. We believe that some tweaks in the motor controller algorithm could reduce or even completely remove this noise. Our goal is to roll out a software update before the end of this year.
"

 

[Stefan Mikes]

Searching a bit in various forums, especially in MTB forums that use the TQ50 motor, I come across the fact that this same issue is well-known to them, and they have even received a response from the manufacturer clarifying their stance. I am attaching a YouTube link where I found the following response from TQ:

"@RobRidesEMTB
To add - the motors are near silent on descents - barely any noticeable rattles (especially compared with Shimano / Bosch)Also, TQ responded to a small number users experiencing noises. Here’s what they said:

Hey Rob! Just wanted to give you a quick heads up regarding the noise discussionsWe are currently working on this topic. It has no influence on the motor’s performance or durability and seams to be no more than a peculiarity of one of the sprag clutches of our motor. If the motor’s assist is very low (less than ~ 10W) it seams that the electric motors torque is not enough to rotate the clutch, but not fully engage it. This can lead to the weird rattling/grinding noise. The forces in such a scenario are however extremely low and do not put any mentionable wear on the internals of the motor. From everything we know and all the 1000s of field testing kilometers we have already done this issue is nothing to worry about. Nevertheless the low noise is one of our strongest USPs and we are working on a solution. We believe that some tweaks in the motor controller algorithm could reduce or even completely remove this noise. Our goal is to roll out a software update before the end of this year.
"

A good explanation Antonio! Thank you!

 

[AntonioAlfaro]

I also found this interesting discussion:

TQ HPR50 Grinding Noise

OK, I''ve just now figured the factors that produce the grind sound, for me. Any time, and for me every time, the pedal rate and force i apply on the crank fall below what's needed to activate the motor, the grind sound occurs. For example this will occur while riding on a level surface in a...

www.emtbforums.com

 

[AntonioAlfaro]

I am tricking the motor. I don't allow the assistance power to drop to low levels where the grinding noise occurs. I achieve this by quickly shifting to higher gears so that my legs are always delivering power. Also, on easy segments of the route, I turn off the motor.

 

[AntonioAlfaro]

For those who like real data, I conducted a test on the Domane+ SLR 2023 until the battery was completely depleted. Two purposes; 1) To determine at what battery percentage the assistance disconnects, 2) To determine the real total battery capacity in Wh. During the test, I thought I would be notified in some way when the battery reached 15% remaining, but that didn't happen. The system continued to work normally regardless of the level of assistance used, and I reached 5% remaining without any issues. However, just as I passed to 4% remaining battery, the assistance cut off. The e-bike started to function like a regular bicycle. The display showed 0% battery.
For me this is an important piece of information to consider when planning a new ride and wanting to avoid surprises. So, remember the magic number: 5%. Back at home, I started charging the battery until it was back to 100%, and the energy required for that was 335 Wh. This data is equally important in planning new routes, as it represents the actual maximum available capacity (not 360Wh as we might be tempted to think). I hope this modest measurement is useful to you. Regards.

 

[AntonioAlfaro]

I must say that before conducting this test, I was searching for information on the web, and the only thing I managed to find was an FAQ document from Trek, which is on the Domane+SLR 2023 page in the Service section. In that document, there is a very interesting answer that says: "
Are there any other special instructions for the battery?
Please note that the battery will only last to about 15% capacity the first time it is depleted. So
don’t be alarmed if the range on your first ride is a little shorter than expected. After the first
full depletion and subsequent charging, the battery management system will “learn” what it
needs to know and will deplete all the way to 0% on future rides.
Also note that any time the battery reaches less than 10% charge, the motor output will be
reduced to 110 watts. The battery level indicator will flash to indicate Low Battery mode.
".
It seems that in the first deep discharge, the system cuts off before reaching 0%, but in subsequent deep discharges, the system reaches 0%. This aligns with what you report having observed.

 

[AntonioAlfaro]

Full Discharge, Second Test: As you may recall, the purpose of the first discharge test was to verify the discharge percentage at which the TQ system would cut off during the first deep discharge. The cutoff was confirmed at 5%. Today, in the second deep discharge test, we aim to determine the percentage of discharge at which the system cuts off (TQ says ....the battery management system will “learn” what it needs to know and will deplete all the way to 0% on future rides). This second test confirms that the system cuts off when reaching 0% discharge, thus aligning with the manufacturer's specifications. With this verified data, you can now plan your journeys with accurate final values. Regards.

 

[Sean McIllwain]

I just purchased the Pinarello Nytro E5 (same TQ motor as the Domane+ SLR) and am having multiple issues after just 275 miles.

• I have the dreadful grinding noise. It did not make this noise until recently.
  
  
• The motor doesn’t always supply consistent power. I was climbing at a very steady pace and it started to surge and then drag. I’ve also began noticing this on the flats. It can feel perfect for awhile and then soddenly, it feels off, as if the motor power is not being supplied smoothly.
  
  
• A few times; the motor didn’t turn on at all. Top tube screen was on, but no power. Restarting the bike corrected it.
  
  
• Once the motor quit and presented an error code after I took a break on a climb. Tried restarting but the error codes kept popping up. As I was riding to my shop, I tried restarting once more and the motor was back. As I had expected the errors to stay displayed, I didn’t take note of the exact codes

Anybody experiencing these issues?

 

[AntonioAlfaro]

I just purchased the Pinarello Nytro E5 (same TQ motor as the Domane+ SLR) and am having multiple issues after just 275 miles.

• I have the dreadful grinding noise. It did not make this noise until recently.
  
  
• The motor doesn’t always supply consistent power. I was climbing at a very steady pace and it started to surge and then drag. I’ve also began noticing this on the flats. It can feel perfect for awhile and then soddenly, it feels off, as if the motor power is not being supplied smoothly.
  
  
• A few times; the motor didn’t turn on at all. Top tube screen was on, but no power. Restarting the bike corrected it.
  
  
• Once the motor quit and presented an error code after I took a break on a climb. Tried restarting but the error codes kept popping up. As I was riding to my shop, I tried restarting once more and the motor was back. As I had expected the errors to stay displayed, I didn’t take note of the exact codes

Anybody experiencing these issues?

Hello Sean, in general terms, I would recommend that your system undergo a diagnostic by the vendor. They have tools and software to carry this out without much complication. I've read from TQ that when errors like in your case arise, the system should be diagnosed, and often it's due to a lack of software updates.

 

[Sean McIllwain]

Thanks Antonio. I took my Nytro to my dealer with these issues. Other than being cleaner, the bike came back still exhibiting these problems. I’m beyond disappointed as my dealer is one of Boulder’s oldest and highly regarded. Not to mention, I’ve spent tens of thousands of dollars with them over the years.

I’ve had a Specialized Creo for 3 years that is a joy to ride. I had the same expectations from the TQ powered Nytro. So far, it’s no contest

 

[AntonioAlfaro]

Thanks Antonio. I took my Nytro to my dealer with these issues. Other than being cleaner, the bike came back still exhibiting these problems. I’m beyond disappointed as my dealer is one of Boulder’s oldest and highly regarded. Not to mention, I’ve spent tens of thousands of dollars with them over the years.

I’ve had a Specialized Creo for 3 years that is a joy to ride. I had the same expectations from the TQ powered Nytro. So far, it’s no contest

Sean, demand that they give you the printed report of the diagnostic result performed with the "TQ Service Tool". Otherwise it would mean that they do not have that tool and would not be providing the required service.

 

[AntonioAlfaro]

Sean, demand that they give you the printed report of the diagnostic result performed with the "TQ Service Tool". Otherwise it would mean that they do not have that tool and would not be providing the required service.

Sean, please find here info about latest software realeses. Also check for the error codes if not updated.

Software updates for e-bikes with TQ-HPR50

The latest software updates for TQ e-bike components. Bring your e-bike up to date and use the full range of functions. View updates now!

www.tq-ebike.com

 

[Sean McIllwain]

Sean, please find here info about latest software realeses. Also check for the error codes if not updated.

Software updates for e-bikes with TQ-HPR50

The latest software updates for TQ e-bike components. Bring your e-bike up to date and use the full range of functions. View updates now!

www.tq-ebike.com

Thanks again, Antonio!

 

[Sean McIllwain]

Sean, please find here info about latest software realeses. Also check for the error codes if not updated.

Software updates for e-bikes with TQ-HPR50

The latest software updates for TQ e-bike components. Bring your e-bike up to date and use the full range of functions. View updates now!

www.tq-ebike.com

Sean, please find here info about latest software realeses. Also check for the error codes if not updated.

Software updates for e-bikes with TQ-HPR50

The latest software updates for TQ e-bike components. Bring your e-bike up to date and use the full range of functions. View updates now!

www.tq-ebike.com

Turns out. my dealer does not have the TQ Service Tool. Moving forward, I don’t see how they can offer me proper service. The only fair solution I can think of is to refund me so I can find a manufacturer/dealer that can assist me in the future. Would love to others’ thoughts?