Tsdz2 brass gear change (weird high pitched hum)

Brian park

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Oct 12, 2018
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Hi All

Not sure if this is a common problem or maybe not even a problem but having changed to a brass Gear cog, I cant help but be quite self conscious when I set off on my commute. The motor is properly loud for the first 5 minutes under load. Lots of torque initially which seems to dwindle along with the whirring/humming sound. Thereafter I'm pretty sure I'm not getting the full motor power for the rest of the journey (10 miles)
Same issue happens from every cold start. Does anyone have an insight into what might be going on here? More grease necessary? Something else I cant think of or should be looking for?

Thanks guys!
 

Nealh

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Changing to the brass gear is a known issue and yes the motor is noticeably louder in use. Over on Endless sphere they will likely have an answer for you.

As aside it is known that heat/over heating can have an effect on power. It is advised to fit a heat temp sensor and to carry out the heat conduction mods, over time any excessive heat will demagnetise the coils evident by the browning/miscolouring of said windings.
 
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Nealh

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What is your perceived cadence ? To high cadence can lead to lack of power under stock settings, 60rpm - 90rpm is it's approx. cadence. Once one gets near to the top end then the overall motor rpm of 4000 is reached and then power will back off.
 
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Nealh

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Bikes4two

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Out of interest, why did you change to a brass gear - was the blue one knackered? If it was, how many miles had you done?

What power/voltage is your motor BTW?

The brass gear is reported by many as being noisier. Some also think that keeping the blue gear is a safety feature (as like a fuse is in an electrical circuit) and will wear earlier to prevent damage to more expensive gear parts.

I looked at my blue gear after 1500km and it was in perfect condition.

I've yet to use my motor in warm weather so as yet I've not experienced the need for extra cooling - I'll have to wait and see on that one. I do wonder under what circumstances (motor power, voltage, assist level, ambient temperature, mountain or flat route) those needing cooling are riding in?
 

Brian park

Pedelecer
Oct 12, 2018
38
6
52
Out of interest, why did you change to a brass gear - was the blue one knackered? If it was, how many miles had you done?

What power/voltage is your motor BTW?

The brass gear is reported by many as being noisier. Some also think that keeping the blue gear is a safety feature (as like a fuse is in an electrical circuit) and will wear earlier to prevent damage to more expensive gear parts.

I looked at my blue gear after 1500km and it was in perfect condition.

I've yet to use my motor in warm weather so as yet I've not experienced the need for extra cooling - I'll have to wait and see on that one. I do wonder under what circumstances (motor power, voltage, assist level, ambient temperature, mountain or flat route) those needing cooling are riding in?
Well. Its a bit of a saga. Originally had a TSDz2 750w motor which I used for a year and after 3000km the blue gear wore so badly I lost all assist. Ordered a brass gear only to find I couldn't open the motor as the crappy Allen bolts rounded and had corroded and fused to the body of the motor. Bought new motor and immediately fitted the brass gear (and greased all the bolt threads!).
All was fine until I noticed the first few minutes of riding started to produce a loud whine, which died away especially if I put some effort into the cranks.
I am pretty sure the torque also dies away too though but have no way to measure that other than my gut feeling and feedback through the cranks.
My Bosch 250w bike screams up inclines that the tsdz2 struggles with. I was just wondering whether that is normal or whether I need to open up the motor and check all the bits are in the right place.
My guilty conscience tells me it's something I've done wrong!
 
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Brian park

Pedelecer
Oct 12, 2018
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52
What is your perceived cadence ? To high cadence can lead to lack of power under stock settings, 60rpm - 90rpm is it's approx. cadence.Once one gets ear to the top end then the overall motor rpm of 4000 is reached and then power will back off.
It's when I'm going up hills I notice the power drop-off so cadence is very low
 

Brian park

Pedelecer
Oct 12, 2018
38
6
52
Changing to the brass gear is a known issue and yes the motor is noticeably louder in use. Over on Endless sphere they will likely have an answer for you.

As aside it is known that heat/over heating can have an effect on power. It is advised to fit a heat temp sensor and to carry out the heat conduction mods, over time any excessive heat will demagnetise the coils evident by the browning/miscolouring of said windings.
Should the motor feel warm to the touch after a period of usage (40mins)?
 

Nealh

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Because of the poor temperature conductivity inside motor (too many air voids), if one is feeling a warm motor externally then the internal winding temp is going to be high. Don't forget the motor has firmware settings that will automatically reduce power and finally shut down power when it gets too hot, the min temp in the firmware is 65c when power is reduced and at 80c the motor shuts down. At the higher figure is when the motor windings ca start burning and demagnetise, once this occurs the motor is damaged.
 

Brian park

Pedelecer
Oct 12, 2018
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Because of the poor temperature conductivity inside motor (too many air voids), if one is feeling a warm motor externally then the internal winding temp is going to be high. Don't forget the motor has firmware settings that will automatically reduce power and finally shut down power when it gets too hot, the min temp in the firmware is 65c when power is reduced and at 80c the motor shuts down. At the higher figure is when the motor windings ca start burning and demagnetise, once this occurs the motor is damaged.
Definitely not 65c - more like 40c as in pleasantly warm to touch on after being out in the cold. How can I check if the windings are damaged? Are there any pics maybe?
 

Nealh

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At a third or quarter or so of the price of a bosh, one can't compare the tsdz2. There is no comparison as build quality is chalk and cheese, the endearing features of the tsdz is it is relatively cheap to buy and easy to repair with OSF to adjust core parameters to better suit ones riding style.
Temp is a well documented issue and as little as 400w of power can cause issues as can setting the current too high. There are various threads on ES and all are long it is worth delving into them as bedtime reading to digest more in to keeping them running.
Even motors with stock screens benefit from the basic OSF tinkering but from all sides which I read a temp sensor and the basic added heat pads/conduction transfer internally is all but a must so when riding one can observe the temp and adjust riding style/power applied to keep below 60c.
 
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Nealh

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Definitely not 65c - more like 40c as in pleasantly warm to touch on after being out in the cold. How can I check if the windings are damaged? Are there any pics maybe?
That what you are feeling is the outside shell temp, the inside core temp will be much higher and a real hot potato to handle as the conductivity flow is low. Air conductivity is poor and approx 0.24 w/mk, the heat mods use thermal conductive pliable pads that vary from 4w/mk up to 16 w/mk to shed the heat faster to the outer ali shell. The forum users say the mods work and most can keep internal heat < 60c by this method and adapting the power usage.
 
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Nealh

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Should the motor feel warm to the touch after a period of usage (40mins)?
Quite easily reading the threads, all depends on current used/power and terrain amongst a few of the variables.
 

Nealh

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Nealh

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Aug 7, 2014
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West Sx RH
At the least being that there are known issues with build quality and heat issues a heat sensor is the minimum to fit. One doesn't have to use the OSF stuff to accomplish this, but can easily add a battery operated temp sensor with a small display or opt for the one that require 5v power supply. The latter one can use a spare 5v and Gnd supply left vacant on the controller pcb.
 

Brian park

Pedelecer
Oct 12, 2018
38
6
52
At the least being that there are known issues with build quality and heat issues a heat sensor is the minimum to fit. One doesn't have to use the OSF stuff to accomplish this, but can easily add a battery operated temp sensor with a small display or opt for the one that require 5v power supply. The latter one can use a spare 5v and Gnd supply left vacant on the controller pcb.
Crikey! I never knew I was going down such a rabbit hole. Naively I assumed it was a fit and forget system. Best start reading the posts and do some proper swatting!
 

Brian park

Pedelecer
Oct 12, 2018
38
6
52
At a third or quarter or so of the price of a bosh, one can't compare the tsdz2. There is no comparison as build quality is chalk and cheese, the endearing features of the tsdz is it is relatively cheap to buy and easy to repair with OSF to adjust core parameters to better suit ones riding style.
Temp is a well documented issue and as little as 400w of power can cause issues as can setting the current too high. There are various threads on ES and all are long it is worth delving into them as bedtime reading to digest more in to keeping them running.
Even motors with stock screens benefit from the basic OSF tinkering but from all sides which I read a temp sensor and the basic added heat pads/conduction transfer internally is all but a must so when riding one can observe the temp and adjust riding style/power applied to keep below 60c.
So effectively, without a temp sensor I should regulate my power usage and go easy when I notice the motor is giving out less assist to the cranks than I feel it should? Getting a temp sensor fitted feels like a bit of a pain but I may be wrong!
 

Bikes4two

Esteemed Pedelecer
Feb 21, 2020
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Well. Its a bit of a saga. Originally had a TSDz2 750w motor which I used for a year and after 3000km the blue gear wore so badly I lost all assist. Ordered a brass gear only to find I couldn't open the motor as the crappy Allen bolts rounded and had corroded and fused to the body of the motor.
3000km on a 750w motor and I'm guessing no maintenance such as a bit of a strip-down and re-grease (hence the seized Allen bolts). It's arguable whether that sort of maintenance should be needed, but from other forums and youtube, regular checking for grease, worn gearing and bearings looks to be a wise thing for those so inclined (preventative maintenance vs 'if it in't broke don't fix it').

Bought new motor and immediately fitted the brass gear (and greased all the bolt threads!).
My guilty conscience tells me it's something I've done wrong!
I suppose you could always refit the blue gear to see if the noise goes?
My Bosch 250w bike screams up inclines that the tsdz2 struggles with. I was just wondering whether that is normal or whether I need to open up the motor and check all the bits are in the right place.
I ride with other 250w Bosch motor riders and my TSDZ2 seems to perform as well as theirs - hmmm?
 
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Nealh

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The tdsz2 is engineered pretty poorly and not only the nylon gear is an issue, as mentioned a mildly warm day will lead to toasting the motor. The crankshaft is known to sheer on the rhs as well and various bearings /needle cages can fail.
Without any mods the motor has to be babied, the cheapish price/plenty of spares and the fact it is a TS drive is the reason why it is liked along with techy's who have OSF'd it for all to do.
 
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