Another new TQ motor: hpr40

Anyone know the ballpark efficiency (Power out/Power in) of the TQ40. I read that the downside of the Harmonic Drive is efficiency at the lower end of the range. Thanks to TRW I understand the TQ motor is unique and curious to learn if the benefits of the TQ come with a cost of lower efficiency and range?
Officially it’s 90%. I’m still putting the data together from my rides, but it’s not seeming to be inefficient in terms of average meters gained per full charge compared to the Mahle, for example. I‘m likely to use meters gained/Wh to take into account the difference in battery capacity (290Wh TQ, 350Wh Mahle in the Gain I tested) between the systems in my comparison video, though I’ll report on the overall range in m of each system (as it applies to me) too.
 
Officially it’s 90%. I’m still putting the data together from my rides, but it’s not seeming to be inefficient in terms of average meters gained per full charge compared to the Mahle, for example. I‘m likely to use meters gained/Wh to take into account the difference in battery capacity (290Wh TQ, 350Wh Mahle in the Gain I tested) between the systems in my comparison video, though I’ll report on the overall range in m of each system (as it applies to me) too.

Thanks. 90% would be impressive. Looking forward to your upcoming reviews. And yes, comparing range can be difficult when you can't really measure Whr or Ahr or access the BMS data.
 
Anyone know the ballpark efficiency (Power out/Power in) of the TQ40. I read that the downside of the Harmonic Drive is efficiency at the lower end of the range. Thanks to TRW I understand the TQ motor is unique and curious to learn if the benefits of the TQ come with a cost of lower efficiency and range?


When Specialized rolled out the Creo2 they published this chart comparing their new motor’s efficiency with the TQ hpr50 and others. I saw a lot of room for misleading marketing hype and I asked Spec if I could see their test data and methodology. Like “rider cadence between 80 and 100”, and how that could mean one motor tested at 100 while another at 80, or one at low load and another at maximum load, different temperatures, etc. They said it’s for “internal use only”.

Then I emailed TQ and asked for their comment and I was told they prioritized quietness over efficiency but it was better than the Specialized chart showed. That sounded like an honest (perhaps incomplete) answer. So looking at the chart I assume the specialized 1.2 sl is up to 80% under ideal conditions, likely less under real world conditions. And my assumption is that the TQ 50 is less than that, but at least 65%, and that low figure is probably under the least favorable conditions. All based on my interpretation of a marketing chart with no data supporting it.

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Again, just from press blurb, but TQ claim a system efficiency of 80% on the HPR50, and we know that the ‘40 has a few differences in the motor (like the lack of a second freewheel/clutch) so I guess that’s where the claimed additional 10% efficiency comes from. I’d love to know the real figures!
Not really surprising Spesh press rate their main future rival for road bike motors very low…
 
Again, just from press blurb, but TQ claim a system efficiency of 80% on the HPR50, and we know that the ‘40 has a few differences in the motor (like the lack of a second freewheel/clutch) so I guess that’s where the claimed additional 10% efficiency comes from. I’d love to know the real figures!
Not really surprising Spesh press rate their main future rival for road bike motors very low…
Yes, it’s logical that the hpr40 will prove to be at least as efficient as the HPR50, likely better. Besides evolving motors, there are still gains to be made in battery technology which will increase range per battery size/weight = more miles per same physical size battery.
 
Here’s another test report I came across showing the efficiency o the HPR50.

Wow that is great stuff! I had a long phone call with the ‘40 Product Manager at TQ last week, trying to sort out those crazy claims of their customer services person, and one of the things I also wanted to check was whether they had addressed the derating that the HPR50 was known for. She said not only had the case design changed, to allow for greater cooling, but that also the 40 produced considerably less heat as it is rated at 200w and they had seen no derating in their testing. That would up the efficiency considerably. I’ll be looking out for Testmybike’s review of that one!
 
Wow that is great stuff! I had a long phone call with the ‘40 Product Manager at TQ last week, trying to sort out those crazy claims of their customer services person, and one of the things I also wanted to check was whether they had addressed the derating that the HPR50 was known for. She said not only had the case design changed, to allow for greater cooling, but that also the 40 produced considerably less heat as it is rated at 200w and they had seen no derating in their testing. That would up the efficiency considerably. I’ll be looking out for Testmybike’s review of that one!
It’s nice to get your input and analysis, both here and on your YouTube channel! And you’re so right about the heat/efficiency connection: basic physics says less heat = better electrical/mechanical conversion. Thanks for your reviews!
 
It’s nice to get your input and analysis, both here and on your YouTube channel! And you’re so right about the heat/efficiency connection: basic physics says less heat = better electrical/mechanical conversion. Thanks for your reviews!
Ditto, and Calcoaster thanks for the comparison data you provided.
 
That looks more like an average efficiency of 60-70% which should show up in real world testing of battery range. Anyone know the approximate average efficiency of the X-20. About the same, better, worse?
 
The testmybike site has a few other interesting articles.
 
While @stompandgo is a fine and nice guy, we have known @mschwett from his best side for several years now. Mark in an accomplished road cyclist who has owned many analog bikes and e-bikes, and was always approaching cycling from the engineering and scientific side; he was not interested in how a human would provide their watts but how many watts were required to accomplish the goal.

Mark has helped me a lot with planning for my hilly gravel races. It was him to make me aware the rider and the e-bike must provide enough combined power to allow climbing up a certain grade at a certain speed. The gearing ratio -- he correctly reasoned -- was only to provide the necessary cadence so the e-bike motor could run at the max efficiency. Additionally, a rider who could muster a high cadence, was expected to deliver more leg power to the cranks than a slow "grinder".

I respect @stompandgo as an experienced road cyclist and a coach as well as his expertise in the bicycle mechanics.

You two should shake your hands and become friends instead of going to war and Ignore.

Signed:
The one who is the most quarrelsome person on these Fora (except his sworn enemies) :D
 
That’s what they advertise- 200 watts peak or continuous. Meant for lightweight road bikes and riders who want some assist but still expect to work for it.
Calcoaster, something is either strange or... it is a marketing hype. The older Specialized SL 1.1 motor is providing 240 W peak mechanical power, which is 35 Nm at the reference angular speed of 6.28 rad/s (60 rpm). TQ HPR 40 is therefore weaker than the SL 1.1, and it has the torque of 31.8 Nm at 6.28 rad/s, certainly not 40 Nm. Interesting.
 
Calcoaster, something is either strange or... it is a marketing hype. The older Specialized SL 1.1 motor is providing 240 W peak mechanical power, which is 35 Nm at the reference angular speed of 6.28 rad/s (60 rpm). TQ HPR 40 is therefore weaker than the SL 1.1, and it has the torque of 31.8 Nm at 6.28 rad/s, certainly not 40 Nm. Interesting.
They claim 40nm and 200 watts peak and nominal for the hpr40. The hpr50 claims 50nm and 300w peak, 250w nominal. It’s upgrade now being used by trek and BMC, the hpr60 claims 60nm, 350 w peak and depending on the source, 250 or 300w nominal.

I read the reason for the two different nominal values for the hpr60 is related to the European rules limiting continuous power to 250w. Maybe their marketing uses different specs depending on where they are advertising.

I don’t know why the basic formula of torque = force X distance doesn’t always seem to work out when dissecting motor power ratings. Must be some magic involved.
 
I don’t know why the basic formula of torque = force X distance doesn’t always seem to work out when dissecting motor power ratings. Must be some magic involved.
The basic formula for torque in rotating systems is T = P / omega
where,
T = torque [Nm]
P = power [W]
omega = angular speed [radian/s]

Forget the 250 W. We are only talking the motor mechanical peak power. The only thing that matters is the max motor power. Torque is a marketing gimmick to hide the actual peak power from the legislators. Torque without the angular speed is of no meaning. Therefore:
  • TQ HPR 40 with 200 W of power is the weakest motor. Torque @60 rpm or 1 Hz or 1/s (6.28 rad/s) is 31.8 Nm
  • Specialized SL 1.1, 240 W goes next; torque 38.2 Nm
  • TQ HPR 50, 300 W; torque 47.8 Nm
  • Specialized SL 1.2, 320 W; torque 51 Nm
  • TQ HPR 60, 350 W; torque 55.7 Nm.
That's all. "Torque" is gaslighting. It would be a real parameter only if the mfg gave the reference angular speed, or RPM at the motor spindle (these are equivalent).
 
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