THE NEW PERFORMANCE CX RACE, FOR EBIKE RACING

https://www.emtbforums.com/the-new-performance-cx-race-for-ebike-racing/

This is the mid drive haters society in here.

i did not think it would even get 1 reply lol

I don't know anyone that hates mid-drive I'm certainly a fan for the right application. The issue for me with Bosch is the proprietary nature of their products and throw away bikes when the bikes are uneconomic to repair. I wouldn't apply the same criticisms to many kit mid-drive motors. Mid-drive motors can be a fantastic choice and definitely the right choice for an off-road e-mountain bike.

 

I did notice this;

 

'The Performance CX Race is still a legal motor with 250W nominal power and the 25km/h cut-off speed. But Bosch have maximized the time we get full motor power. '

 

The nominal power bit again seems suspect to say the least. If you are delivering full power for longer and drawing very high current from the battery how does this not effect the legal rating of 250W?

 

I believe the 250W nominal rating is farcical legislation but how come premium ebikes get away with it but a cheap Chinese ebike gets hammered when it takes far less out of its battery, in fact typically cheaper lower spec cells not capable of such high current and overall a much lower Watt hour battery pack too.

 

Bosch is a pretty despicable company, they were a major player in the diesel gate scandal, put a spy in Dyson to try and learn secrets and have often paid huge fines for anti-competitive practices this could be an upcoming ebike scandal when someone actually takes time to look at their so called nominal rating.

 

As hub motors especially direct drive have more surface area to dissipate heat they heat up slower so if a 250W mid-drive motor allows for 800W then hub motors should be allowed a higher wattage rating again because they can take higher wattage for longer over their nominal rating.

 

To me this reads as Bosch have got away with their higher wattage ebike motors before so are pushing the envelope even more to what they can get away with to give themselves an even greater competitive advantage over their competitors. Yet Bosch have a long history of being a very dishonest company that ignores legislation more so than many of its competitors.

Here we go down the rabbit hole of definitions.

As I understand it the 250w rating of motors is what that motor can take continuously without overheating.

So, a motor that can run at 800w that doesn't hot complies with this 250w rating. Then, if stamped by the manufacturer as 250w, it is legal.

This is what makes the nominal power definition bonkers - as far as i can see, it's meaningless.

 

It is power that does the work. Would a more precise way be to limit the power output of contollers? Not current as a 10A controller at 36v outputs less power than a 10A at 48v.

However, if controllers were limited to an output of 250w, given inefficiencies in the system, I certainly would no longer be cycling the hills of west Wales.

 

I do agree about Bosch though. I wouldn't go near their locked in products.

In practice, if 25km/h is securely implemented, power beyond 250W has limited use. Brilliantly useful for hill climbing, very beneficial for accelerating cargo bikes from rest, and in all cases gets you to maximum speed that bit quicker.

 

Designing to cope with peaks somewhat above 250W should result in better reliability as most of the time the motor and controller are operating well below the limits of destruction.

Here we go down the rabbit hole of definitions.

As I understand it the 250w rating of motors is what that motor can take continuously without overheating.

So, a motor that can run at 800w that doesn't hot complies with this 250w rating. Then, if stamped by the manufacturer as 250w, it is legal.

This is what makes the nominal power definition bonkers - as far as i can see, it's meaningless.

 

It is power that does the work. Would a more precise way be to limit the power output of contollers? Not current as a 10A controller at 36v outputs less power than a 10A at 48v.

However, if controllers were limited to an output of 250w, given inefficiencies in the system, I certainly would no longer be cycling the hills of west Wales.

 

I do agree about Bosch though. I wouldn't go near their locked in products.

 

If a vacuum cleaner has a nominal rating of 1500W you don't expect to see it pull 5000W for extended periods. Looking at most geared hub ebikes if they have a 7A controller (36Vx7A=250W) they have a maximum current rating of 12-14A about twice they aren't drawing 22A from the battery for extended periods.

 

Lets say Bosch were bought to task and their ebike motors had to be restricted to 500W peak, maybe 600W for very short spikes of current that is going to be a significant drop in torque performance so again leaving people with a product inferior to how originally sold same as dieselgate where 17 million Bosch devices were designed to function illegally with regard vehicle fuel mixtures and changing parameters when the device knew it was being tested. Operating illegally to give themselves a competitive advantage.

From what I've read Bosch 250W controllers are 20A (or [mention=11305]soundwave[/mention] 's is), therefore I wonder if Bosch are using some sort of buffer to increase and sustain higher power for longer periods of time? Some electric and hybrid supercars boost performance for short bursts using supercapacitors. Otherwise the power of Bosch ebike motors stated on this thread make no sense.

 

https://www.engineeringtoolbox.com/electrical-motor-calculator-d_832.html

Power (Watts) = Torque (N.m) x Speed (RPM) / 9.5488

 

If you read, for example EN15194, its the mechanical output power that measured under certain conditions. (Its rather complicated).

EN15194.pdf

Edited October 1, 20223 yr by Sturmey

there is a sclass bosch gen 4 with a 28mph cut off speed that is also gen4 with the same controller just with different software settings for higher top speed both motors are the same bar this.

 

and its the same with the race motor but limited to 15mph and you get a extra 60% assistance up to 400% done via the software and 150g lighter limited numbers and no parts available so out of warranty it would be a bin job and if you race bikes in events most manufactures will void the warranty anyway.

 

race class means it can hit over 28mph which this so called new bosch motor is not it is just marketing bs and if they opened up the software like bafang you could set it to 800% assistance or just rip out the controller and use a 3rd party one and dump 40A in to it.

 

my bike would be classed as race as with a dongle i can hit near 40 mph at max rpm but some ppl just dont like this fact and it will do no damage to my motor either as the last one lasted 8 years and did not die.

there is a sclass bosch gen 4 with a 28mph cut off speed that is also gen4 with the same controller just with different software settings for higher top speed both motors are the same bar this.

 

and its the same with the race motor but limited to 15mph and you get a extra 60% assistance up to 400% done via the software and 150g lighter limited numbers and no parts available so out of warranty it would be a bin job and if you race bikes in events most manufactures will void the warranty anyway.

 

race class means it can hit over 28mph which this so called new bosch motor is not it is just marketing bs and if they opened up the software like bafang you could set it to 800% assistance or just rip out the controller and use a 3rd party one and dump 40A in to it.

 

my bike would be classed as race as with a dongle i can hit near 40 mph at max rpm but some ppl just dont like this fact and it will do no damage to my motor either as the last one lasted 8 years and did not die.

 

I've just ordered these sheepskin earpads for my Sennheiser HD600 headphones - I bet they'll only last about a year, as usual

 

https://www.amazon.co.uk/Replacement-Sennheiser-Headphones-Sheepskin-Cushions/dp/B07G5X8YD9/ref=

https://www.ebay.co.uk/itm/255338237388?hash=item3b73584dcc:g:dcsAAOSwt1ph5lfy&amdata=enc%3AAQAHAAAA4Py9522UaOzaOUM%2BKM8aEwekeZmDDqcprzZOC1v9SYDXC5uGBH1FoGdZZq3NiSbwtEh88MxFRmrmqbwzrPW0xcjP%2Bj5eFy1fSU0pIQn2MFpiNd4L9qHgWLQuzCcc6pYavzykG5BRtFwy4MHIrVOJxoLHoCDIbl6T58PaQ6uNwyHTGo1LcWt7TMUXfxT%2BLFCZCuV68kOmL3pFS7RsoI7Ai5s6lXh%2FOx7o3iFraL9DAJUeMz26Mis6IgjQYo2X6D7%2BxEl%2BfKZ%2Fmvd5%2BRasbL%2FNANqQL%2FM95uNGrh8mTObhZ2Xt%7Ctkp%3ABk9SR6L9r8HyYA

https://www.ebay.co.uk/itm/255338237388?hash=item3b73584dcc:g:dcsAAOSwt1ph5lfy&amdata=enc%3AAQAHAAAA4Py9522UaOzaOUM%2BKM8aEwekeZmDDqcprzZOC1v9SYDXC5uGBH1FoGdZZq3NiSbwtEh88MxFRmrmqbwzrPW0xcjP%2Bj5eFy1fSU0pIQn2MFpiNd4L9qHgWLQuzCcc6pYavzykG5BRtFwy4MHIrVOJxoLHoCDIbl6T58PaQ6uNwyHTGo1LcWt7TMUXfxT%2BLFCZCuV68kOmL3pFS7RsoI7Ai5s6lXh%2FOx7o3iFraL9DAJUeMz26Mis6IgjQYo2X6D7%2BxEl%2BfKZ%2Fmvd5%2BRasbL%2FNANqQL%2FM95uNGrh8mTObhZ2Xt%7Ctkp%3ABk9SR6L9r8HyYA

 

Got those, they feel icky, which is why I went with sheepskin this time - Sennheiser's original velour pads feel brilliant, and that's usually what I buy... but trying to find genuine spare parts has become a freaking nightmare now that Sennheiser have sold product licensing to that German hearing aid company. No driver capsules on sale anywhere now, and complete headband units are impossible to source in the UK. I'll go with Beyer Dynamic and Sony next time. Trouble is, these HD600 still sound better than anything else I've tried. Bloody annoying.

some places in Germany want you to order 200 euros worth of stuff even to post it to the uk and others charge so much it is just not worth bothering anymore.

 

i need a new head band as paint has chipped off like they all do but im not paying crazy postage prices to get one.

 

like everything these days they expect you to throw it in the bin and buy new no matter what it cost out of warranty.

My carbon headband splintered after it fell off the desk too many times, and is now being held together at the top with zipties, until I get around to repairing it with epoxy. One of the reasons I bought them in the first place - aside from the very neutral mostly flat frequency response, was because at the time every part was replaceable... now that feature is gone, I may actually have to buy something else (which won't be as good) when these drivers get fuggy.

bosch are doing the same thing as going forward with the smart system the new frame batts wont work with the older motors and locked out via software..

 

so when they stop making the older batts that's it i got a new one this year but when thats dead no bike.

 

https://www.audiosanctuary.co.uk/sennheiser-replacement-foam-headband-pad-for-hd650.html

Edited October 1, 20223 yr by soundwave

I certainly hope right to repair laws will be passed by the time you need a new battery... if that dimwit Truss doesn't block them for being anti-business.

dont worry that is getting sorted cant say much but buy then i will be able to get it recelled in the uk so can keep this thing going forever

 

3rd party batts are out there but made in germany and no postage.

If not, you could go on a German holiday and bring one back in hand luggage.

if it comes to that i wont have any other option but a company in Germany can recell them for about 500 euro but again no postage.

From what I've read Bosch 250W controllers are 20A (or [mention=11305]soundwave[/mention] 's is), therefore I wonder if Bosch are using some sort of buffer to increase and sustain higher power for longer periods of time? Some electric and hybrid supercars boost performance for short bursts using supercapacitors. Otherwise the power of Bosch ebike motors stated on this thread make no sense.

 

https://www.engineeringtoolbox.com/electrical-motor-calculator-d_832.html

20A at 36V is 720W, but from what I've read on other forums some Bosch motors have been measured at 22A current draw despite being 250W nominal rated power, that is likely peak power for short periods. When you look around at nominal vs maximum rated power its normally approximately a double difference for most motors i.e. 250W would allow for a peak of 500W for short periods perhaps 600W for a few seconds just as a momentary surge. However for a Bosch motor used off-road climbing a steep incline or hill the motor is operating perhaps at 800W for quite some time. I'd be interested to see how Bosch calculate their 250W rating, their mathematics and why can't other manufacturers use the same formula?

 

As I said before a direct drive hub motor has no internal gearing and a larger surface area so heats more slowly so even if rated to 250W nominal maybe able to maintain 500W for longer as the heat build up is slower before it would have to thermally throttle itself.

 

Looking at that standard posted elsewhere they show a power curve diagram with 250W shown and the curve only peaks at around 300-325W looking at that diagram. That standard is incredibly vague though with regard power rating of motors it refers to another standard on how motors are rated 60034-1:2022.

Power (Watts) = Torque (N.m) x Speed (RPM) / 9.5488

 

If you read, for example EN15194, its the mechanical output power that measured under certain conditions. (Its rather complicated).

 

Looking at that standard there are test procedures about how the motor functions with regard pedalling and applying power but that is not the electrical characteristics as far as I can see. Elsewhere they state maximum 48V system and refer to 60034-1 for how motor ratings are calculated which is purely focused on electrical motor ratings. That standard I guess would give clear indication of how the nominal power of a motor should be rated. The formula you give above looks like a watt rating for a human rider and how its calculated.

Here we go down the rabbit hole of definitions.

As I understand it the 250w rating of motors is what that motor can take continuously without overheating.

So, a motor that can run at 800w that doesn't hot complies with this 250w rating. Then, if stamped by the manufacturer as 250w, it is legal.

This is what makes the nominal power definition bonkers - as far as i can see, it's meaningless.

 

It is power that does the work. Would a more precise way be to limit the power output of contollers? Not current as a 10A controller at 36v outputs less power than a 10A at 48v.

However, if controllers were limited to an output of 250w, given inefficiencies in the system, I certainly would no longer be cycling the hills of west Wales.

 

I do agree about Bosch though. I wouldn't go near their locked in products.

I don't think it would at all. (if Ltd to 250w be useless on your hills)

I have a power meter built into my Giant Fathom and agreed it does occasionally see well above 250 w (most I, ve see n is 607 w) but that is when I, m going almost bonkers, spinning crank at 110 rpm on steep prolonged hills. (in Derbyshire) If I take it steady and keep cadence around 70,I can easily (steadily) climb any hill and power reading stays below 250.

And, I, d guess I, m amongst heavier riders at 105kg and certainly not fit taking my AF into account.

Look at it from your battery's point of view. I get over 2 hours hard riding even on my 400 wh battery. That's well under 250 w average. I, ll up load some power /cadence graphs... It actually amazes me how much help even 200w actually gives.

I think current rules /legislation is fine. My pedelec legal mtbs do fantastic job. All of them.

 

That 283 w max corresponded to a cadence of 103..You can see from graph nearly all climbing is done well under the 250 w threshold.

Edited October 2, 20223 yr by Zlatan

Looking at that standard there are test procedures about how the motor functions with regard pedalling and applying power but that is not the electrical characteristics as far as I can see. Elsewhere they state maximum 48V system and refer to 60034-1 for how motor ratings are calculated which is purely focused on electrical motor ratings. That standard I guess would give clear indication of how the nominal power of a motor should be rated. The formula you give above looks like a watt rating for a human rider and how its calculated.

The German forum has more info on same. The 48v max is to reduce electrocution risk. Its always mechanic power thats measured. There is no actual direct limit on maximum power. I have translated for your convenience. This I presume is the European standard. I'm not sure how much of it is applicable to England.

https://www.pedelecforum.de/wiki/doku.php?id=e-motor:nenndauerleistung#messung

 

1. Maximum rated continuous power

1.1. definition

The "maximum rated continuous power" relevant for pedelecs is defined as follows in Article 3 No. 35 of European Regulation No. 168/2013 on the approval and market surveillance of two-wheel, three-wheel and four-wheel vehicles of January 15 , 2013, valid from January 1, 2016:

• For the purposes of this Regulation […] the expression […] “maximum rated continuous power” means the maximum power over 30 minutes at the output shaft of an electric motor as defined in UN-ECE Regulation No 85; ...
  

1.2. Measurement

UN-ECE regulation no. 85 as far as relevant for pedelecs: PDF version

- Clause 2.3. (to be measured is the mechanical power):

• "Useful power" is the power that is determined on a test stand on the crankshaft or a corresponding component at a corresponding engine speed
  

- Clause 2.4. (the rated continuous power is defined):

• "Maximum 30-minute power" is the maximum useful power of an electric propulsion system at DC voltage, as defined in paragraph 5.3.1., that a propulsion system can deliver over a period of 30 minutes on average.
  

- Clause 5.3. Description of tests to measure net power and maximum 30-minute power of electric propulsion systems

• The electrical drive system must be equipped in accordance with Annex 6. ...
  

- Clause 5.3.2. Determination of the highest 30-minute effort

• 5.3.2.1. The engine and all its equipment shall be conditioned for at least four hours at a temperature of 25 ± 5 °C.
  
• 5.3.2.2. The electric propulsion system must be operated on the test bench at a power level which, according to the manufacturer's specifications, most closely corresponds to the maximum 30-minute power level. The speed shall be in a range where the net power is more than 90% of the maximum power measured in accordance with paragraph 5.3.1. This speed must have been recommended by the manufacturer.
  
• 5.3.2.3. Power and speed are to be recorded. The power shall be within ± 5% of the power value at the start of the test. The 30-minute peak performance is the average performance over the 30-minute period.
  

- APPENDIX 6 METHODS OF MEASUREMENT OF NETWORK POWER AND PEAK 30 MINUTE POWER OF ELECTRIC PROPULSION SYSTEMS (here the critical thermal component is now defined):

• 2.5.4. … For air-cooled drive systems, the temperature must be maintained at a point specified by the manufacturer to within + 0/- 20 K of the maximum value specified by the manufacturer. ...
  
• 2.5.6. If necessary, an auxiliary cooling system may be used to maintain the temperature within the limits given in paragraphs 2.5.4 and 2.5.5.
  

Explanation:

The decisive (limiting) parameter for the maximum rated continuous power defined here is the thermal component.

Starting from the 25°C of the 4-hour pre-tempering, the temperature may rise by a maximum of 20 K (1K = 1°C) during the measurement. At the start of the measurement (without the auxiliary cooling system), the engine has a temperature of 25°C, so the manufacturer can only specify 45° as the maximum value for exhausting the range. At the start of the measurement it is -20 below the 45, ie at 25°, in the following 30 minutes the motor may then reach a maximum of 45°. With the auxiliary cooling system according to 2.5.6 (this must then probably be started at the beginning of the measurement), the engine temperature may first drop, but then must not rise above 20K from the lowest point reached.

Put simply, the engine, operated with 250 W, may only produce enough waste heat that the engine temperature does not rise more than 20°C within 30 minutes. In addition to the waste heat produced, the decisive factor is the "cooling capacity" of the housing.

With additional cooling ribs on the housing of a "250 W continuous power motor" you could, for example, significantly increase the heat dissipation, operate it with more than 250 W and still keep to the 20K → more than 250 W nominal continuous power → no more pedelecs.

This method according to UN/ECE No. 85 roughly corresponds to the previously applicable "S1 continuous operation", see Section 2.2 below

(Manfred, 04/23/2017)

1.3. Conclusion

The maximum peak power is legally unlimited for EU pedelecs. Since the legally only relevant maximum continuous power is determined under laboratory conditions at 25 °C ± 5 °C, when driving at lower temperatures and with stronger airflow, significantly higher maximum continuous power than the maximum continuous power can be achieved.

When determining the maximum rated continuous power of 250W, the manufacturers are given a great deal of discretion. According to UN-ECE regulation no. 85 number 5.3.1.3. immediately before the start of the test, run the engine on the dynamometer for three minutes with the power output being 80 per cent of the maximum power at the manufacturer's recommended speed . When determining the highest 30-minute power according to clause 5.3.2.2. the electric propulsion system must be operated on the test bench at a power which, according to the manufacturer's specifications , most closely corresponds to the maximum 30-minute power. The speed shall be in a range where the net power is more than 90% of the maximum power measured in accordance with paragraph 5.3.1.This speed must have been recommended by the manufacturer. Incidentally, an alternative determination of the maximum rated continuous power according to DIN EN 15194:2009-06 Appendix D is possible outdated version, newer version unfortunately not publicly accessible .

This practice-oriented European legal situation enables current pedelec drives with a rated continuous power of 250 W as specified by the manufacturer to have a maximum power that in practice is around four times the rated continuous power, depending on the drive system: subject of motor characteristics and maximum power ; Forum post on the BionX ; another forum post on the BionX ; https://www.velomotion.de/magazin/2022/04/e-mtb-antriebe-2022-test/

Thread on the topic: 250 W rated continuous power of the pedelec - legal basis and measurement

2. Operating modes in general

 

2.1 Basics

The international regulation IEC 60034-1 (corresponds to the European EN 60034-1) was applied to the determination of the maximum rated continuous power until the introduction of the above-mentioned special regulations.

There are specific operating modes for each motor, ie alternation between load and rest periods. When determining the load limits, an ambient temperature of 40 degrees without additional active cooling is assumed. Also see https://de.wikipedia.org/wiki/Nennbetriebsart

2.2. S1 continuous operation

Operation with a constant load condition, the duration of which is sufficient to reach thermal equilibrium. See also IEC 60034-1 clause 4.2.1 and: forum post

2.3. S2 short-term operation

Operation with a constant load condition, but which does not last long enough to reach thermal equilibrium and a subsequent pause, which lasts until the engine temperature differs by no more than 2K from the temperature of the coolant.

2.4. S3 intermittent operation

Operation made up of a sequence of similar operating times, each of which includes a period of constant load and a pause, where the starting current

does not appreciably affect heating.

The German forum has more info on same. The 48v max is to reduce electrocution risk. Its always mechanic power thats measured. There is no actual direct limit on maximum power. I have translated for your convenience. This I presume is the European standard. I'm not sure how much of it is applicable to England.

https://www.pedelecforum.de/wiki/doku.php?id=e-motor:nenndauerleistung#messung

 

does not appreciably affect heating.

 

That reads like overly complex and manipulative legislation but I guess direct drive hub motors are more limited because they dissipate more heat according to that standard because of their greater surface area. I've seen other legislation not pedelec based ebikes and seemed much easier to navigate. The sooner the UK moves away from such awful EU legislation the better. However that reads as 1000W peak power allowed under very careful conditions of the motor which perhaps are not viable to manufacture currently perhaps a motor and components that generates less heat, less friction etc. So its like legislation designed to make manufacturing more complicated and expensive and make ebikes less accessible to consumers because of higher pricing. Simple logical legislation is consumer friendly and this is a long way from it. Overly complex designs have poor reliability, high maintenance costs and are scrapped sooner. They also lead to more proprietary and anti-competitive components. This legislation seems to give an unfair competitive advantage to premium high end ebikes and how much power they can deliver.

 

Perhaps this is why so many institutions around Europe have given up on ebike legislation enforcement. The UK there is little enforcement and you see people in Europe who have built ebike kits that are throttle only and have no issues where they are. It's like a wholesale rejection and lack of understanding of this abysmal legislation. The power characteristics are now ignored except for excessively powerful ebikes and the maximum 15.5mph check is purely focused on.