Setting a Standard?

[Patrick]

Is it reasonable to expect customers to then delve into lengthy research and search internet forums to get a clear picture?

If I wanted to buy a car I'd need to do a just as much research, I've never owned or driven a car so there's a lot I would need to learn be for I could start to make sense of the manufacturers' claims. Alternatively I could find someone who I trust to help me (this could be a reputable car dealer, in an ideal world at least).

When I went to one of our local bike shops to get my wife an unassisted bicycle the salesman spend a long time finding out what she wanted and going through the options available to help her pick the bike that was best for her, the alternative would have been me trawling the Internet for the same information.

So to answer your question, yes, when it comes to complex purchases like bikes, cars, pets, computers, mattresses and anything else that presents a bewildering array of options to the uninitiated then it reasonable to expect customers to either: research the options themselves; find some knowledgeable person to help them; or guess and hope.

One way the e-bike industry could improve matters when they quote things like range is for them to say where the numbers came from. The Advertising Standards Agency's code of practice says:

3 Substantiation
3.1 Before distributing or submitting a marketing communication for publication, marketers must hold documentary evidence to prove all claims, whether direct or implied, that are capable of objective substantiation.
Relevant evidence should be sent without delay if requested by the ASA or CAP. The adequacy of evidence will be judged on whether it supports both the detailed claims and the overall impression created by the marketing communication. The full name and geographical business address of marketers should be provided without delay if requested by the ASA or CAP.
CAP - CAP Code Item
​

So if the bike sellers are complying with the code then it will be easy for them to supply the extra information needed to put their claims into context.

 

[flecc]

Rider input of ebike = variable rate's of pedalling are converted into power applied to the drive.
Driver input of car = variable rate's of accelerator are also converted into power applied to drive.

Two very different things. The rate/speed of pedal travel continuously alters the power levels in a superimposition on the rest of the determining factors. The speed with which a driver thrust down the accelerator only has one effect at that brief moment, the power from then on remaining the same, no matter what rate they'd pressed down the accelerator.

There may even be comparisons between the ebike controller and the engine management system of a car.

That's what I said when I pointed out that both are part of the reepective motors and not part of the rider/driver control system. Therefore still not relevant.

For the sake of debate, let's say your right, result's of any test would be meaningless in real world situation's with all the variable's involved.

Exactly my point!

Major ebike manufacturer instruct their design/developement team to produce a range of competiton beating ebike's and at the same time improve their current range.

How in this case, would they determine what is competition beating or an improvement on their own product's, if as you say test result's and measurement's are rendered meaningless by the variable's?

One, they determine the motor/controller characteristics to give the optimum for e-bike usage, commensurate with the law. Two, their battery manufacturers match a battery to the consumptrion of that motor/controller combination and endeavour to give the maximum capacity/range while matching the bike manufacturer's size/weight requirements. Those optimums determine competition beating capability. In fact the design aspects for beating the competition are mostly on style and quality, legal restrictions impeding progress elsewhere.

Going back to an earlier comment regarding bypassing the pedelec on a Panasonic? I'd wager that Panasonic have a plugin device that can simulate pedaling at varying rate's electronically for test purposes.

Possible but doubtful as there is no need. Their design brief is confined by the very strict Japanese law and you can read about that in my article here. Since the system is designed to be a direct match for human actions, their best test modules are humans, using a machine which of necessity falls short of human capability has no point.
.

 

[onmebike]

Missing what I've posted earlier in the thread Xcytronex. Two identical bikes, ridden in company together on the same route, one giving 62 miles and one 30 miles.

Two Fireblades ridden close together in the same way would have similar consumptions, 2 to 1 difference would be impossible.

Their riders could not influence the outcome in remotely the same way that those two Panasonic equipped cyclists did, so not similar at all
.

Regarding the two ebike's. How does the same route have a 32 mile variation?
Were both riders of similar build and keep their machine's within the realm's of assistance at all time's, matching gear change's, speed and without the use of throttle? I think not, but if so, I would be investigating the possibility of a fault or variation in setup, of the lower achiever. This may also raise the question of how precise are the manufacturing standard's, when two identical machine's ridden under identical condition's vary so much.
This comparison is a prime example of why a standard test in a controlled enviroment, using predetermined variable's, would benefit prospective buyer's.
In some respects the range of an ebike could be claimed to be almost infinite provided you keep outside the assistance limitation's.

 

[flecc]

standard?

If we want the industry to be regarded as responsible, reasonable and customer focussed surely we have an interest in getting accurate and reliable data in the hands of people wanting to try or buy the products? Hence, I believe, the suggestion of a standard.

Its certainly desirable, but will always be defeated by the human input variable which alters range by at least a 2 to 1 ratio. The car industry being used for comparison has no relevance since cars have one or rarely two precisely measurable power sources. The second human source on an e-bike is variable over a huge range, Chris Hoy against a 75 year old pensioner cycling to the shops for example. To give actual power examples, a high proportion of e-bikers might only manage 100 watt input continuously for one hour, against the top riders over 450 watts.

But that's only the physiology, psychologically behaviours vary with regard to the responses to power availability. A typical Cytronex customer will regard his/her input as the primary source and get as much as 35 miles from it's tiny battery. A typical "shopper" e-bike user will usually regard the motor as the primary power source and get half that mileage or less from a battery over twice the size.

And of course range is not the only factor, often not a factor at all. E-bikes are frequently bought for hill climbing assistance and a measure of that capability is often of more importance. However, once again all the variables of the human factor apply, and pedelec makes motor only climb ability impossible to test separately.

All these circumstances add up to what I've been saying all along, only maximum and minimum range figures, or upper and lower hill steepness capabilities can realistically be published for each bike, and in both cases those two figures will always be wide apart due to the huge breadth of individual human capabilities.
.

 

[flecc]

Regarding the two ebike's. How does the same route have a 32 mile variation?
Were both riders of similar build and keep their machine's within the realm's of assistance at all time's, matching gear change's, speed and without the use of throttle? I think not, but if so, I would be investigating the possibility of a fault or variation in setup, of the lower achiever. This may also raise the question of how precise are the manufacturing standard's, when two identical machine's ridden under identical condition's vary so much.
This comparison is a prime example of why a standard test in a controlled enviroment, using predetermined variable's, would benefit prospective buyer's.
In some respects the range of an ebike could be claimed to be almost infinite provided you keep outside the assistance limitation's.

You really don't seem to understand the implications of a hybrid where a human is one of the power sources, or understand everything I've told you about the Panasonic system. Like all Japanese manufacturing, the standards are impeccably high and are not at issue.

The riders rode together and they don't have throttles so the system itself determined to main operating conditions were the same. The difference was the cycling fitness ability of the two similarly aged riders, the high power input of one resulting in the system, which recognises that, having to use far less motor power to run in the same way for the same result as the other rider.

As for your comment on variations, all e-bike ranges vary by at least 2 to 1 and as much as 3 to 1, depending in the rider's cycling ability, which is precisely why quoting accurate figures is impossible.
.

 

[Bandit]

Published car consumption figures cannot be expected to be as universally reproducible as, say, top speed, but I guess people are meant to assume that any driver will get better consumption from a car with better consumption figures, even if his figures don't correspond closely with the published ones. That assumption may still be false for any particular individual, but I guess the standard ensures that it will be broadly true for a statistically valid sample of the driving population.

We've recently acquired an electric car of the "light quadracycle" type to experiment with in our hilly rural area, and people ask how far it will go. The manufacturer quoted ranges and speeds are clearly for flat roads, and actual range and speed varies considerably with the terrain and the number of passengers. Even in a conventional car you wouldn't expect to achieve maximum range at maximum speed, but since you can actually drive an electric car at its maximum speed most of the time, I expect many consumers will be disappointed to discover this awkward reality.

From my limited experience, I think it would be very hard to produce anything as useful for electric bikes, if only because you'd have to factor in the mass and shape of the rider, which represent the majority of the load being moved by the combined - and roughly comparable in power - motors of the bike and the rider. With our electric car, the payload would rarely be more than a quarter of the all-up-weight and has little or no effect on the drag profile. With a conventional car the payload has even less effect.

 

[Wisper Bikes]

Range

Thanks Bob for your PM, giving me the opportunity to reply to your post.

The figures on our website regarding other manufacturers was compiled a good 18 months ago and there may have been changes.

Figures published for our bikes were based on one of my guys in China, who weighs nearly 12 stone, riding around the trading estate adjacent to our factory. The minimum figure was achieved with the bike set at full assistance (high) and the maximum was when it was set to minimum (low). These figures were achieved in real conditions on the road with stops, turns and other road users getting in the way!

When I looked up figures claimed by other electric bike manufacturers I noticed that pretty well everyone was claiming around the 10Wh/mile as a minimum range, which in the conditions described above seemed about right.

However.....

The industry has become more sophisticated with many new products coming onto the market. Every manufacturer/distributor understandably wants to show their product in the best possible light, hence the recent ridiculous claim of over 100 miles from a 24v 9A battery. Of course this is possible in perfect conditions but unlikely. The point is who could argue the claim? If I was asked to prove my maximum range, by adjusting the assist level to almost zero I could set one of my bikes up to achieve 100's of miles.

The problem in setting a standard is, as discussed in this thread, there are so many variables, even without taking the rider into account.

I stand by my suggestion that if all manufacturers were to set up a bike so it could be run at 15mph on throttle only with exactly the same weight of rider in controlled indoor conditions, we could as an industry produce an accurate set of data. This test would show exactly the range possible from the electric part of a bike coupled with its rolling resistance and weight. I don't imagine for a second that this will ever happen as those using smaller batteries would argue that their drive system makes a difference, when in my opinion torque sensor systems driven through the bike's gears are less efficient than a pure hub drive.

We all have 250W of power to play with. As long as everyone is using a decent hi efficiency brushless motor and has low rolling resistance the results from such a simple test would be similar in terms of Wh/mile. Bikes with big batteries would simply go further than bikes with small batteries.

Another useful test would be to measure the time it took for each electric bike to accelerate from 0 to 15mph on throttle only, this would quantify torque. Again big batteries would normally out perform small batteries depending on the gearing of the motor.

A final test showing maximum speed unrestricted would iron out any differences in motor gearing as those bikes with high torque settings would not be as fast as those with low.

However.....

In my opinion the best solution currently is that we bring as many bikes together as possible on the same day to run tests over the same track with similarly fit riders and all bikes carrying the same weight. We could draw lots for which cyclist rides which bike and run a series of tests.

OK not so accurate but those who did well could gloat and those that did not do so well could blame the inefficiency of the tests. The electric bike buying public could form their own conclusions!

All the best

David

 

[flecc]

But it's not possible to run on throttle only on pedelec only systems David, so they couldn't be included.

Nor can systems like the Panasonic/Yamaha one be set up to run as throttle systems for the test, since doing that would completely change the way in which they work, excluding all their internalised control systems, and therefore make the results invalid. And the absolute killer for such testing is their servo motors, only driving during pedal downthrusts with a rise and fall power curve within each downstroke.
.

 

[alex_h]

yes the competition would only make sense for those who have throttles only.

those who have pedelecs would need a separate test

 

[Wisper Bikes]

OK it's a tough nut but one that needs cracking.

Maybe the idea of all getting together at a track would be worthwhile?

Or do we simply offer the advice that in good conditions a rider of 12 stones should expect a return of about 1 mile/Wh. Which takes us back to where we started!

Regards

David

 

[flecc]

Maybe the idea of all getting together at a track would be worthwhile?

Or do we simply offer the advice that in good conditions a rider of 12 stones should expect a return of about 1 mile/Wh. Which takes us back to where we started!

Regards

David

That's the trouble David, we are always taken back to the same point with any investigation.

The track test will result in all manufacturers using a clone of Lance Armstrong for the best result, so totally unrealistic for average e-bike customers.

To illustrate, Kalkhoff when introducing their Panasonic equipped e-bikes ran a test with three riders who each turned in a 100 mile range on the run, this publicised later. The best I've seen from any owner is 62 miles, but most struggle to get to 40 miles.

I see no solution in a situation where the rider provides anything from zero to 100% of the power on e-bikes, since that means the rider power has to be quoted. Since that physical capability varies by up to 5 to 1 among the population, we are again left with a wide range of possibilities.
.

 

[Old Timer]

Don`t know if it has been suggested but I suppose one way of at least separating the bikes would be to get the same rider to ride all of the bikes over the same route under similar weather conditions.(after eating the same breakfast

 

[Wisper Bikes]

Human error

I agree Tony, I just feel we should be giving electric bike riders so form of advice regarding range that can be accepted by all.

If we were to use a local cycle club to do the testing for us asking for 10 or so equally fit people and then drew lots to determine which bike was ridden by which rider we may be able to make the first steps to making a standard.

Regards

David

 

[onmebike]

Two very different things. The rate/speed of pedal travel continuously alters the power levels in a superimposition on the rest of the determining factors. The speed with which a driver thrust down the accelerator only has one effect at that brief moment, the power from then on remaining the same, no matter what rate they'd pressed down the accelerator.

Above statement suggests the accelerator has no more affect than an on/off switch and the car a single speed. To my mind the accelerator compare's favourably with the various element's required for electric motor speed control.


One, they determine the motor/controller characteristics to give the optimum for e-bike usage, commensurate with the law. Two, their battery manufacturers match a battery to the consumptrion of that motor/controller combination and endeavour to give the maximum capacity/range while matching the bike manufacturer's size/weight requirements. Those optimums determine competition beating capability. In fact the design aspects for beating the competition are mostly on style and quality, legal restrictions impeding progress elsewhere.

Difficult task without a target[the competition] to aim for in my opinion.
The manufacturer determine's motor/controller to give optimum for ebike usage and battery on maximum capacity/range. The question is, what determine's the optimum for ebike usage?
To reach the optimum, the manufacturer must have taken the variable's into account, hence optimum for usage. How did they calculate the variable's?


Possible but doubtful as there is no need. Their design brief is confined by the very strict Japanese law and you can read about that in my article here. Since the system is designed to be a direct match for human actions, their best test modules are humans, using a machine which of necessity falls short of human capability has no point.
.

A device that simulates various degree's of pedalling would have its place on the test bench for test and fault finding purposes, would also reduce the work force.
I'm sure a machine could easily replicate the motion and torque required for a pedalec system. From what you've said about the Panasonic system, its far more intelligent than the rider
Panasonic must employ a bizarre collection of human test module's if their to represent all possible end user's, or do they use an average weight, average height, average fitness Transexual for their adult range.

 

[flecc]

Originally Posted by flecc
Two very different things. The rate/speed of pedal travel continuously alters the power levels in a superimposition on the rest of the determining factors. The speed with which a driver thrust down the accelerator only has one effect at that brief moment, the power from then on remaining the same, no matter what rate they'd pressed down the accelerator.

Above statement suggests the accelerator has no more affect than an on/off switch and the car a single speed. To my mind the accelerator compare's favourably with the various element's required for electric motor speed control.

No it doesn't, it says what it says. In more detail, that the speed during the travel of the accelerator pedal as it's pressed down does not affect the power at the final point intended when it's reached, for example full throttle gives the maximum power available. That power is the same regardless of how fast the driver presses down the pedal

The speed of the pedals as they are rotated does affect the ultimate power level in a Panasonic unit. The faster the pedal rate beyond a certain point, the more the end power reduces, totally different.

I've courteously, very patiently and endlessly explained how this system works and can do no more. Others have understood and appreciated the information I've given as they've posted. If you simply cannot understand it and how it is in no way similar to a car system after all the help I've given, I cannot help that, so will not respond again to any further challenges to my correct information.
.

 

[onmebike]

No it doesn't, it says what it says. In more detail, that the speed during the travel of the accelerator pedal as it's pressed down does not affect the power at the final point intended when it's reached, for example full throttle gives the maximum power available. That power is the same regardless of how fast the driver presses down the pedal

The speed of the pedals as they are rotated does affect the ultimate power level in a Panasonic unit. The faster the pedal rate beyond a certain point, the more the end power reduces, totally different.

I've courteously, very patiently and endlessly explained how this system works and can do no more. Others have understood and appreciated the information I've given as they've posted. If you simply cannot understand it and how it is in no way similar to a car system after all the help I've given, I cannot help that, so will not respond again to any further challenges to my correct information.
.

I appreciate your input to this thread, the purpose of which was to explore the possibilities of developing a series of test's for comparing ebike's. Not comparison's with car's, although that side was interesting.
I don't want to appear ungrateful for your input, which you have explained in great detail and I'm sorry you saw my opinion as a challenge, it wasn't intended that way. The fact I don't agree has little to do with understanding.
Whereas many have made positive suggestion's yours have tended to be on the negative side and restrictive to one particular system type, namely Panasonic. Unfortunately we disagree on certain point's but I hope this won't affect future unrelated discussion's.
I do think a test model is possible, even with simulated variable's. Although not perfect it will be relatively accurate under one set of condition's. those that match the model.
Final comment on the throttle. End power may be the same irrespective of how fast the throttle is opened, but it will be reached quicker.Kind of reversal of the Panasonic system.

 

[flecc]

Unfortunately we disagree on certain point's but I hope this won't affect future unrelated discussion's.

Of course not, I'll always be happy to discuss any other matters.
.

 

[onmebike]

Of course not, I'll always be happy to discuss any other matters.
.

I appreciate that.

 

[NRG]

There is absolutely no point in having a result for a single set of test conditions when the real world usage conditions are infinitely variable. It helps nobody. I think I'll stop reading this thread as its completely exasperating.

 

[flecc]

I think I'll stop reading this thread as its completely exasperating.

I know the feeling!
.