But is it even an e-bike?

The test is to apply 250w for 30 minutes at which point the temperature must have stabilised.

The  EPAC EN standard I’m looking at says the power is measured when the motor is at a stable temp, it can’t be over 250W at that point.

The  EPAC EN standard I’m looking at says the power is measured when the motor is at a stable temp, it can’t be over 250W at that point.

Assuming it’s EN 15194 then I don’t have access to that document anymore, but when you say it has to be at a stable temp, what power is being applied to it?

From what I remember it means as a condition of the test you apply not more than 250W for 30 minutes and at that point the temperature has to be stable.

It’ll be the power the battery and controller apply. There isn’t anything about running it at a set output eg 250W though it’d be the place to start if the motor manufacturer rates it at 250W. If it’s stable there (temp variation over an hour), run it harder and see if it’s still stable.

If it’s stable there (temp variation over an hour), run it harder and see if it’s still stable.

From what I remember the standard doesn’t say to do that though?

It just says to run it at 250W and see if it’s stable.  If it is it passes.

Like I said earlier, if you used a motor that was too small the temperature wouldn’t be stable at 250W and the motor would fail.  If it’s a test to determine an upper limit then motors that are below that limit should be fine but according to the wording that’s not the case.

As a vehicle, I think it’s a great idea for inner city delivery work. But a bike? It’s no more a bike than my car is.

Use them on the road, registered, with insurance and a suitably trained and licensed driver, perfect – no problem with that.

From what I remember the standard doesn’t say to do that though?

It just defines the spec to pass. The spec is max CRP of 250W and CRP is defined as the output of the motor at thermal equilibrium. The IEC doc defines running at thermal equilibrium so the test detail is in that.

It just says to run it at 250W and see if it’s stable.  If it is it passes.

It doesn’t say that exactly in the EPAC standard, but yes if you did that plus showed that it heated up when run over 250W output it’d pass.

Not a bike, remotely. Saw some e-trikes  doing deliveries in Belfast recently with a huge box on the back. They (and the riders) looked unsafe at best. The appear to pose a pretty big risk to pedestrians and riders/drivers to me.

Kinda feels like there needs to be a rule that to classify as an EPAC, it should be possible to propel the vehicle via the pedals with the battery disconnected.

Otherwise, the pedals are just a throttle and if that’s the case, how is a foot throttle different from a hand throttle and it therefore being classified as a motorbike?

(I should say I don’t have a problem with the concept if it reduces the number of delivery vans, but do very much feel like its not “electric pedal assist” if the pedals don’t work without the electric)

how is a foot throttle different from a hand throttle

One is twist and hold, the other has to be continually rotated so makes things like cornering under full power impractical. I don’t believe a series hybrid is outside the scope of what e-bikes are meant to be (and see my earlier point about how most speed-sensor hub motor ebikes will power you along the flat w/o a chain on them already).

If it were a foot press-pedal rather than trad cranks I would see the point .. but I wouldn’t be against that either – many people don’t buy e-bikes to pedal, they just want easier/convenient transport. No-one is asking for pedal e-cars to get a bit of exercise on the way to work. When it comes to urban transport I’m be in favour of EPAC power restricted throttle-only e-bikes. If people don’t want to pedal that’s fine, it’s still far better than driving and safer on the road than those sketchy tiny-wheeled e-scooters.

Size and weight of some cargo bikes do blur the lines, I get that. Overall I tend to look at all this as opportunities for clean, lighter weight transport options to replace cars rather than being too rigid on what an electric bike should be. The product possibilities can evolve faster than the standards and infrastructure and I’m not convinced that waiting for standards to catch up and infrastructure to be built first is the way to go in such a car-fixated world.

Size.

Cycle superhighways are pretty congested but due to the small footprint of a normal two wheeled bike, the different speeds of cycle traffic can pass each other.

They are too big a footprint to fit in many junctions and turnings, they also won’t pass through the anti terrorist measures on bridges or between bollards or restricted width paths.

These things are 90cm wide, aren’t they? MTB handlebars are 80cm – whack a pair of panniers on and they’ll be nudging 90cm quite easily.

They can and do pass through bollards on cycle paths and bridges.

You’ve got “real road users” yelling at them to use the cycle paths and “real cyclists” like you yelling at them to use the roads.

 but yes if you did that plus showed that it heated up when run over 250W output it’d pass.

This is the part I looked carefully for in the standard and couldn’t find.  What does the text actually say about this part?

@brucewee The EPAC EN standard doesn’t spell it out in the way you seem to be looking for because it doesn’t include instructions for test methods for this in the way it defines a brake mount fatigue test etc. Where there are existing standards e.g. in the case of determining electric motor output it uses them.

In the scope section the standard covers ‘maximum 250W continuous rated power’ and it’s clear it’s a maximum. Clause 4.2.14 covers CRP and the IEC standard for motors referenced within that clause covers how thermal equilibrium when running at a constant output is defined and tested for.

Thinking about how a 1000W max continuous rated motor could also pass at 250W (IDK for sure) – the motor industry / manufacturer would have it rated at 1000W and in that sense it fails the EPAC standard scope and couldn’t be used in the first place as it is. Potentially you could limit that 1000W Max CRP motor to 250W Max CRP via the controller, certify that it runs at equilibrium at 250W and have the motor manufacturer re-classify it as a 250W rated motor and that all might pass the EPAC standard – I’m not sure how a test house would view it. I suspect it would pass. The e-bike brand would be using a larger, heavier and more expensive motor than is required and the motor manufacturer would have to do the re-testing and re-classification of the motor for the brand to be able to use it.

There’s no real need to do this for most e-bikes since a 250W max rated motor can peak at 500-750W or so for long enough to give the climbing or acceleration torque needed and 250W is enough to power an average EPAC load at 25kph continually. But the heavier loads of cargo bikes could use the greater peak output a larger motor offers so it may happen and would be ok within the EPAC standard as long as the motor is 250W max rated, certified and the power system / controller won’t let it run at over 250W continually.

Not a bike, remotely. Saw some e-trikes  doing deliveries in Belfast recently with a huge box on the back. They (and the riders) looked unsafe at best. The appear to pose a pretty big risk to pedestrians and riders/drivers to me.

We have multiple logistics companies doing urban deliveries with trikes and quads here. I don’t have a problem with them; they certainly feel less menacing on the roads than delivery vans do to me.

Where there are existing standards e.g. in the case of determining electric motor output it uses them.

In the scope section the standard covers ‘maximum 250W continuous rated power’ and it’s clear it’s a maximum. Clause 4.2.14 covers CRP and the IEC standard for motors referenced within that clause covers how thermal equilibrium when running at a constant output is defined and tested for.

What is the IEC standard it references?

I remember the EPAC EN took me to the IEC document for measuring power output and it was there I looked at the test procedures but I could find no reference to running it above the given power to see that it hadn’t reached thermal equilibrium.

No, the IEC doesn’t state a test procedure*, it defines the continuous running cycle is and how much variation is allowed within equilibrium. I suppose it’s left to the lab to determine the test method/process for the manufacturer who’s motor is being rated. Isn’t the term ‘maximum’ in the EPAC clear in its intent though?

If you’ve read these standards I’m not sure what I can add. Our interpretations of them might vary but neither of us work for SGS or TUV anyway. The point I started on is that the document that defines a motor’s CRP is not specific to the bike industry and the EPAC standard that is, is quite clear on saying that 250W CRP is a maximum.

* So when I said

..the IEC standard for motors referenced within that clause covers how thermal equilibrium when running at a constant output is defined and tested for.

I shouldn’t have said ‘tested for’ as in defining the test, more accurately it’s the need to demonstrate a running condition can be met.

OK but can you tell me the IEC standard that EN 15194 references when it comes to testing power output?  Was it IEC 60349-1?

Isn’t the term ‘maximum’ in the EPAC clear in its intent though?

Not really because maximum continuous power is not a term anyone had heard before ebike legislation and standards started using it.

The meaning of continuous power is the power that can be continuously produced without it overheating.  That is by definition a minimum rather than a maximum, eg, you might be able to run a 500W continuous power motor at 600W continuously without it overheating but it’s not guaranteed.

However, if you sold a 500W continuous power motor that would overheat if you ran it at 400W continuously then it would be a case of mislabeling.

In the same way if you sold an ebike that would overheat if it was run at 200W continuously then that would not be allowed.  It’s a minimum, not a maximum.

Maximum Continuous Power isn’t used anywhere except in relation to ebikes as far as I can see and in this case it really doesn’t make any sense*.

*The only way I can see it making sense is if it was determined that a motor that couldn’t deliver 250W continuously wouldn’t provide enough benefit and shouldn’t be marketed as such.  That’s the only way including continuous power (maximum or not) makes any sense.

Are you two sitting at neighbouring desks in the same electrical engineering firm or something? 😆 Very impressed by those who understand all this, it means nothing to me I am ashamed to say

It’s IEC 60034-1.

Not really because maximum continuous power is not a term anyone had heard before ebike legislation and standards started using it.

Maybe not, that’s going back a while. I’m reading this as it says – continuous power rating is a recognised motor spec and the EPAC regs exclude motors rated over 250W.

The meaning of continuous power is the power that can be continuously produced without it overheating. That is by definition a minimum rather than a maximum,

If you make a motors that you rated as xW continuous power, it would make sense for x to be the max output it can run at continuously, ie safety margin aside go much higher and it could overheat. You can run it under that level for a long time too but why would a motor manufacturer under-rate a product? The customer for the motor wants to know the level they can work it to. I get that a motor brand could under-rate a motor to get past the regs and offer ‘amazing’ performance but testing could uncover that and it’s clearly outside the scope and intent of the standard.

In the same way if you sold an ebike that would overheat if it was run at 200W continuously then that would not be allowed.

There is a  clause in the standard about marking inc the motor power rating – so if you have a 200W motor (that didn’t overheat in use!) and the frame is marked 200W along with the other info needed, that’s fine.

Are you two sitting at neighbouring desks in the same electrical engineering firm or something? 😆

Ha.. I work with bikes inc some of the points around testing standards, just at a generalist level. I wouldn’t last 5 mins in an electrical engineering firm!

 I get that a motor brand could under-rate a motor to get past the regs and offer ‘amazing’ performance but testing could uncover that and it’s clearly outside the scope and intent of the standard.

Thing is, that’s the stage we are at now, imo.

I’ve got a shitty front motor and battery from a crashed supermarket bike on my commuter which is a 250W continuous power motor.

Then you have these guys making a series hybrid system* that can apparently haul 650kg at 25km/hr and is also a 250W continuous power motor.

https://law.resource.org/pub/in/bis/S05/is.iec.60034.1.2004.pdf

Anyway, here’s a link to a dodgy version of IEC 60034-1 for anyone who is interested.  The relevant sections are Section 5 where it says:

5.1 Assignment of rating
The rating, as defined in 3.2, shall be assigned by the manufacturer. In assigning the rating the manufacturer shall select one of the classes of rating defined in 5.2.1 to 5,2.6. The
designation of the class of rating shall be written after the rated output. If no designation is
stated, rating for continuous running duty applies.

5.2.1 Rating for continuous running duty
A rating at whieh the machine may be operated for an unlimited period, while complying with
the requirements of this standard.
This class of rating corresponds to duty type S1 and is designated as for the duty type S1

And then going to section 4.2.1 we get this:

4.2.1 Duty type S1 – Continuous running duty
Operation at a constant load maintained for sufficient time to allow the machine to reach
thermal equilibrium, see Figure 1.
The appropriate abbreviation is .S1.

So the manufacturer specifies the rating (250W) and then they go to section 4.2.1, make sure it’s in thermal equilibrium at 250W, and that’s it.  There is nothing about running it at 300W to make sure it’s no longer in thermal equilibrium.

I’ve looked but I can’t find anything that says so.

*Also, if it is a maximum limit, how do you isolate the battery electric power part of the motor from the human generated electric power part of the motor in a series hybrid system.  All the power is going through the same motor.

Are you two sitting at neighbouring desks in the same electrical engineering firm or something? 😆 Very impressed by those who understand all this, it means nothing to me I am ashamed to say

I’m involved in getting devices through approval so I spend a lot of time going through standards and making sure the boxes are ticked.

One thing I’ve noticed is that what we tell the customers and the general public and what we tell the regulators are very very different.

I’m tempted to put my ebike on the smart trainer in the garage and measure the output

There is nothing about running it at 300W to make sure it’s no longer in thermal equilibrium.

I know .. that’s where the ‘maximum 250W rated’ scope of the EPAC standards comes in and the test houses can uncover a 300W rated motor if it’s marked as a 250W. They may not, or the controller might limit it all to 250W making motor power less relevant (an EPAC is tested as a system not just the motor alone). It might be trading standards or other market surveillance authorities who uncover an overpowered / under-declared e-bike, if so all the product could be pulled off the market for non-compliance with a standard that’s needed as part of CE marking.

Plus, the point about knowing a motor’s capacity at the upper limit being useful and there being no commercial reason to make a motor that can be 1000W rated and certifying it as 500W.

if it is a maximum limit, how do you isolate the battery electric power part of the motor from the human generated electric power part of the motor in a series hybrid system.  All the power is going through the same motor.

An electrical engineer could answer that, see my earlier point on my electronics knowledge level! I’d take a guess that the controller senses/regulates power from the crank alternator and adds to it from the battery. Hence the name series hybrid I think, a motor with 2 power sources in series.

I’m tempted to put my ebike on the smart trainer in the garage and measure the output

Could be an interesting experiment.  Take the chain off and just turn the pedals.  Get the motor up to 300W and see how long it takes to catch fire.

In all seriousness though, I really think this needs sorting out.  Just how much money was spent on the recent consultation on 500W motors?

I’ve been through IEC 60034-1 twice now (from questionable sources, admittedly) and I’ve still not found anything to suggest this standard involves checking the motor is not at thermal equilibrium at more than the rated output (remember the rated output is set by the manufacturer).

And it’s now being used to justify 650kg travelling at 25km/hr as a ‘bicycle’ because it’s rated to 250W.

@stwhannah @Mark, could be an interesting story finding out where this 250W number came from and what it actually means.  I could be missing something in the standard but so far no one has pointed out to me the specific section that shows it’s any kind of measurement of maximum power.

It might be trading standards or other market surveillance authorities who uncover an overpowered / under-declared e-bike, if so all the product could be pulled off the market for non-compliance with a standard that’s needed as part of CE marking.

But again, there is no standard test to determine ‘maximum’ continuous power.  According to IEC 60034-1 there is continuous power and that’s it.

Like I said, as a manufacturer we read the standards and make sure our products meet those standards.  So long as the requirements are met you will get your CE marking.

If the standards need to be changed that’s not the job of anyone except the people who write the standards.  And imo the standards need to be more closely examined.  If for no other reason that no more money gets thrown away on pointless consultations.

I’m tempted to put my ebike on the smart trainer in the garage and measure the output

@HoratioHufnagel you have to do this!

Didn’t we discuss this before? I’m pretty sure you’re misinterpreting the IEC standard and thermal equilibrium.

If I take a fixed pole DC electric motor in a polyethylene case and apply 12V and 21A with a 250W load and run it for 30min it might reach 50C and be running at 250W (ignore efficiency for now).

If I take the exact same motor components and put it in a polypropylene case and apply double the power and load it might reach thermal equilibrium at 90C

If I take the exact same motor components and put it in a aluminum case and apply double the power again and load it might reach thermal equilibrium at 150C

The same basic motor, three different powers and three different thermal equilibriums.  But you cant rate the first option for 500W  or 1000W because it would melt

The reason it has to reach a thermal equilibrium is because the motor will be more powerful the cooler it is.  So if you’re going to measure the power, you need to have a standardized test that says run it for 30min until it’s at operating temperature.

There isn’t some sort of thermal runaway where it never reaches equilibrium if you overvolt it.  Either it’ll reach a new equilibrium or physically fail.  You’re measuring the motors power in which case you’ll define the operating conditions (i.e. voltage, current, etc) that it can achieve that. Or it’s part of a system with a controller that’s designed to control it to that.

You can rate the aluminum cased motor for 250W though, it’ll just run nice and cool.  You’d just put 12V / 21A / 250W on the nameplate.  And in the case of EPAC rules, the rating is as a package, so the controller is limiting you to 250W continuous (but bear in mind it’s averaging that at least over a pedal revolution so it’s more like a peak at 750W for 0.25s then nothing over TDC, then another 750W, etc).

Which is why “full fat” e-bikes have more torque.

P (kW) = (T (Nm) * N (RPM)) / 9549

so

0.250 = 85Nm-1 * rpm / 9549

rpm=28

If you assume it’s only applying torque over half the pedal cycle then it’s ~60RPM (because it’s really a 500W motor, for half the time)

Which is why “full fat” e-bikes feel like they have more grunt than a lightweight version, they can deliver the full power at really low RPM’s.  Whereas a ~40Nm-1 motor won’t even meet 250W unless you’re pedaling really quickly.

^ yes it does say that the rating is based on the manufacturer’s spec and conditions. So the test may be mainly checking for the safe operation at the max 250W crp, not looking for the potential to operate at >250W crp (since the cut off limits speed / the controller limits power to the motor anyway)

Either it’ll reach a new equilibrium or physically fail.

Exactly.

If it doesn’t physically fail (or shutdown due to exceeding the thermal limits) it passes.

There is no test to run it at 300W and if it fails then it passes.

As for the actual test conditions then I would assume they are set out in detail in one of the documents listed in Section 2.

so the controller is limiting you to 250W continuous

There is nothing to say the controller has to limit the power over a given time period, whether that is over individual pedal revolutions or over 30 minutes.

If anyone can point me to the relevant section in the relevant standard where it says it does then I’m quite happy to be proved wrong but the only limit I’ve found is the thermal equilibrium requirement in  IEC 60034-1 which has nothing to do with the controller (unless thermal shutdown is triggered by the controller in which case it would still count as a fail).

There is nothing to say the controller has to limit the power over a given time period, whether that is over individual pedal revolutions or over 30 minutes.

No, there isn’t. It’s down to the manufacturer to be sure the system complies with the scope of the standards and is safe so you might want the controller to stop the system putting out over 250W ‘continually’ if the motor is rated at 250W, or at least check it’s safe if it’s run at a higher level for an extended period and what that period is – and there’s the grey area potential, right?

Amazon seem to be starting what they call E-Bike deliveries in the UK. As with the above they look like small electric vans rather than bikes and unfortunately the article doesn’t discuss the vehicles in any detail, but it certainly seems to be the way a lot of city centre deliveries will be going.

https://micromobilitybiz.com/amazon-begins-e-cargo-bike-deliveries-in-norwich/

They look like EAV E-cargos to me.

Electric Assisted Vehicles Limited (eavcargo.com)

Chain drive from the pedals visible in photo at bottom left. 15mph top speed.  Looks like an E-assist cargo quadracycle to me. 🙂

I approve.

*Googles*

EAV 2Cubed e-Cargo Short Review (youtube.com)

More succinct video: Experiences of a FedEx Express e-cargo bike courier (youtube.com)

Those Amazon jobbies look like the Zedify vehicles you see around Bristol.  I approve – reasonably small, slow, quiet, low emissions.

I much prefer those to the electric scooters that Getir use (or used until recently), which zip around silently at 30mph or more.

And as a pedestrian or cyclist, I’d feel safer with more of those on the roads and fewer ICE vans.  Surely there is no more terrifying sound than the blare of am ageing 2.4 diesel Transit that has spent most of its life in 2nd gear, about 50cm off your back wheel down a street that is too narrow for it to pass, but you know it’s about to do that anyway (probably on this blind corner coming up)

They are too big a footprint to fit in many junctions and turnings, they also won’t pass through the anti terrorist measures on bridges or between bollards or restricted width paths.

That’s going to seriously limit their utility, legal or not.

A mobile barricade that you can loot before you overturn it and set it on fire! Two for one.

They look like EAV E-cargos to me.

Electric Assisted Vehicles Limited (eavcargo.com)

When you look at the stats on those I am surprised they even move.

Dry weight 200kg approx. Max watts 600. Up to 31NM.

Might be fine in a very flat environment, but anywhere hilly no chance !

No windscreen wiper either, thats going to right annoy you when your flying along at 5mph ie no airflow to make the water bead off

Obviously not a bike, but potentially a useful thing. I don’t think building vehicles that fudge the legislation will get the best solution for urban deliveries. It’s probably about time a new vehicle class was formulated for this sort of thing, there have long been exceptions to normal van rules like the Piaggio Ape in Europe or Kei cars/vans in Asia which were workarounds. I guess once motorised, all sorts of regs come in such as crashing and inspections.