Come on be fair! Let the car companies get their mileage sorted first, they have bee around for longer...
You have some competition:
You have some competition:
Complete eBike kit just 3.6kg weight and price £225? Surely not...
- Thread starter Swytch Bike
- Start date
Do two "wrongs" make a right? Surely the correct approach is to claim for only what is possible (based on experience/testing/etc) not on what others are claiming.
Trouble is that what Panda claims is perfectly possible. I've personally shown that 50 miles is possible on a Kalkhoff Agattu with a 26v 10Ah battery, in the hilly North Downs at the age of 71.
My average though on that bike was 35 miles, while some others often much younger subsequently only managed 30 miles or even only 25 miles in a couple of cases.
And therein is the problem, range depends more on the cyclist's ability and inclinations than any other factors. To compete in the market a company feels the need to quote the best, rather than the worst. The seemingly most honest approach of quoting say 25 to 50 miles can't work for two reasons. First, most potential customers won't understand why something more definite isn't being quoted. Second, many will just assume the worst.
To show how ridiculous this issue can become, Kalkhoff using the same motor unit and battery on Pro Connect models had a team of three professional riders cover 100 miles riding together, each using one 10Ah battery!
.
Fair point but, if we can get a man on the moon, surely we should be able to devise a test that accurately compares the maximum range of various battery/motor set ups? Or is it like golf shoes - impossible to manufacture any that stay waterproof for more than 12 months!
Unfortunately not if the test results are to be understandable to customers.
As I pointed out, rider abilities and indeed moods are so variable that consistency isn't possible. Test bike "A" this week and get a result. Next week bike "B" is for test, but the first rider is on holiday so comparisons using another rider will be invalid. Weather too changes and cold affects batteries and even rider performance.
Perhaps the only answer is to theoretically check for maximum range in identical circumstances, but the industry will reasonably want those to be based on best conditions. Like the car tests and just as useless!
.
perhaps the answer is to quote only the battery capacity. That way, customers can see clearly that a 36V 5AH battery is half as good as a 36V 10AH battery. As for range, give a simple indication that if you pedal more, you extend the range and if you only rotate the cranks, then it's 10WH per mile on flat roads without headwind. That way, a 36V 5.2AH battery gives at most 190WH or 19 miles with very little pedaling.
But how many people understand what battery capacity is or how to measure it? Not many...
In our experience even people that think they understand it still call it a "ten amp battery" not a "ten amp hour battery"
Thus there is no getting away from the fact that to market to the general public you have to quote range in miles because people understand that.
No single company is ever going to shoot themselves in the foot by going to market with an understated range when other companies with equivalent products are quoting more ambitious ranges.
The SWYTCH claim of "50 miles" is perfectly reasonable, understandable, and far more fair than what other companies are claiming in similar circumstances.
The only way to change things is to have an international standard / testing procedure that can be followed so everyone is on the same page.
are you sure not many would understand battery capacity?
after all, the capacity is on the label.
That still wouldn't do though. The worst case and the most popular quality ebikes of 2006/7, the powerful but legal Ezee Torq and Quando models, consistently ate 24 Wh per mile when not putting in any pedal effort, even with my light circa 63 kilos and avoiding hills. Both models, 15 miles from 360 Wh across a number of forum members when we surveyed them. For one guy it was almost 33 Wh per mile!
And it wouldn't suit the torque controlled crank motor bikes which issue power according to rider input. Some will scarcely move without appreciable rider input.
.
There you go: "..... an international standard / testing procedure that can be followed so everyone is on the same page." - Eureka!
If you do some market research you'll find that a very small fraction of the mass market (i.e. people that aren't already into eBikes) have any idea whatsoever what an Ah or a Wh is, let alone what Amps or Volts are exactly. Most find it very confusing especially the difference between an Ah capacity at 24V and Ah at 36V.
We take it for granted that it's common knowledge among the eBike community what an Ah or a Wh is and what it measures, and how that translates into what kind of range you can expect. But someone who hasn't studied physics or worked in electronics can't be expected to learn all of this just so that they can be eligible to purchase an eBike.
This is particularly important because the eBike market has been niche for a while, but that is changing, and it is becoming a mass-market.
The Car industry (the best established mass-market to reference i think) adopted MPG because people understand Miles, and Gallons, and because they are common metrics. It's only natural that the eBike industry also adopts something simple and based on miles, so that people can understand it.
Of course, it's not very precise quoting a range in miles, because of all the factors that can affect it, but at least it's understandable to everyone. And there is a certain standard forming on its own which is just the generally accepted conversion of Ah to miles - at the moment it seems to be very commonplace to convert 4-5Ah into "25 miles" and 10Ah or more into "50 miles". We are following this common practice and I think it's the right thing to do because it's actually not misleading, it's just not precise, and more importantly, customers understand it.
We take it for granted that it's common knowledge among the eBike community what an Ah or a Wh is and what it measures, and how that translates into what kind of range you can expect. But someone who hasn't studied physics or worked in electronics can't be expected to learn all of this just so that they can be eligible to purchase an eBike.
This is particularly important because the eBike market has been niche for a while, but that is changing, and it is becoming a mass-market.
The Car industry (the best established mass-market to reference i think) adopted MPG because people understand Miles, and Gallons, and because they are common metrics. It's only natural that the eBike industry also adopts something simple and based on miles, so that people can understand it.
Of course, it's not very precise quoting a range in miles, because of all the factors that can affect it, but at least it's understandable to everyone. And there is a certain standard forming on its own which is just the generally accepted conversion of Ah to miles - at the moment it seems to be very commonplace to convert 4-5Ah into "25 miles" and 10Ah or more into "50 miles". We are following this common practice and I think it's the right thing to do because it's actually not misleading, it's just not precise, and more importantly, customers understand it.
Would you like to form a company to implement and regulate this? We would be your first customer, and if you're successful I think you could make ALOT of money in the long term
that is only because your bike is derestricted. If the assistance is cut off at 15mph, flat road, no headwind, little pedaling or rotating cranks only, you get very close to a known condition where everyone can relate to and the weight of the rider and his/her clothing don't matter much. The 10WH per mile is a typical value for such condition. If you ride on a torque system, then you can deduce the power consumption by the assist ratio, 300% (sport mode): 7.5WH/mile, 100% (eco mode): 5WH/mile.
That didn't apply to the Quando though, it's hub motor was geared in the 20" wheel to just about reach 16 mph when the battery was freshly charged, but average 15 mph overall.
It would happily trundle along on the flat at 15 mph continuously without pedalling, but always eating 24 Wh per mile. 15 Wh per mile was the best possible, simply because the single speed pedal gearing didn't allow exceeding it by pedalling. There's quite a few folders on the market like that, even some with gears.
.
that metric works because there is no user input. On a torque system, user input can be 50% in eco mode, 25% in sport mode. On a simple crank rotation system, user input could be anything from 0% to 100%.
As I said before, if you use 10WH/mile with little pedaling for your estimate on a system like the Swytch, then few people would question its validity.
For people who wonder how I came to 7.5WH for sport mode and 5WH for eco mode when you ride a torque pedelec, the formula is 10WH * n/(n+1), with n the assist ratio.
I am keen to see what Wh/km I can obtain from the GSM when mounted to the trike, it is certainly more efficient than my upright! Anything under 7.5 Wh/km is fine. If I keep the cutoff to street legal 25 km/h the motor should only ever be used on climbing steeper hills so 5 Wh/km should be no problem. But I won't 
so it will be interesting to see how I get on.
so it will be interesting to see how I get on.
There we are, problem solved. Quote the following in pedelec specifications:
Range: 10WH * n/(n+1), with n the assist ratio.
Customers should easily understand that.
.
There's been threads in this forum on this question a number of times in the past eleven years. None has ever got near to resolving the issue, it's an impossible question to answer when one of the power supply elements, (human) is so grossly variable and the pedelec motor systems vary so widely.
.
Related Articles
-
MTF Enterprises announces acquisition of EMU Electric Bikes- Started by: Pedelecs
-
Wisper 806T folding bike wins Which? ‘Best Buy’- Started by: Pedelecs
-
Sustrans calls for protected cycle lanes- Started by: Pedelecs
-
Amazon launch their first UK e-cargo micromobility hub- Started by: Pedelecs
