Who wins in real world use?

Deleted member 4366 · Jan 21, 2011

This looks pretty good.
ExtraEnergy Magazine No 2 online in English - ExtraEnergy.org
You have to download the magazine, which'll tell you just about everything you need to know about electric bike performance - over 200 pages. Its very comprehensive except that they don't include cheap Chinese bikes like many of us have. I'm still trying to digest all the info. There's a very good table on pages 196, 197, which summarises athe performance data.

10mph · Jan 21, 2011

Thank you very much d8veh. That is certainly the sort of thing I have been looking for. I liked the idea of 7 test riders each riding each bike, I like the full description of the test methods, rather than just unsupported claims.

I have printed the comparison pages, but there is a lot to study in the remaining 202 pages which should keep me busy for a few hours.

jerrysimon · Jan 21, 2011

Wow, that looks like a really good publication.

I wish I had had access to that when I first started looking at ebikes. That said I found this forum which was sufficient and interactive

The article on different motor systems on page 44 is very informative for those who want to know the different options.

Seems like it is free as well!

Regards

Jerry

eddieo · Jan 21, 2011

I have just downloaded mag

have read the German version before using Google translator

Back to the question: I would think all bikes would perform in a similar fashion, with none being a clear winner. it simply comes down to choice and taste. The e bike regulations and speed restrictions means any differences will surely be marginal......

10mph · Jan 23, 2011

indalo said:
Other than actually road-testing those bikes that interest us, there's very little forensic data to be found, at least as far as I can see, by which we can compare one with another.

It's all very well reading Tom's glowing account of his new Kalkhoff or Dick's praise of his super-duper new Wisper. Harry, apparently, cannot fault his brand new eZee Torq but all these reviews are necessarily subjective and in isolation mean very little.

If we want to buy a new car, there's shelf-loads full of magazines with all the raw data we might want to inform our choice. You can easily read how fast any car accelerates, what its maximum speed is, fuel economy, emissions, boot space.....anything you might want to know really.

I am encountering similar problems to indalo. The speed I need for my measuring is modest - 10 -mph but I need range more than 30 miles, ideally 40. There is no way I can determine range without a test over a few days. In principle I can get range by using extra batteries (perhaps even carried in my escort vehicle since I am invariably escorted on my occasional long rides).

I thought perhaps that the test data in the Extra Energy Magazine linked by d8veh above might help. But it does not help very much. Even though they have gone to great lengths to compare each bike to how a standard test push bike would perform with an equal amount of rider input, and have thus been able to compute a Support Factor (comapred with the standard push bike), Range and Speed for each bike on 3 different types of route, it seems that rider input is not necessarily the same for each type of bike tested.

What has been done may well be useful to help many people choose a suitable bike, but it does not really help me. This is especially because I recognise very few of the bikes being tested in Germany last summer being available here in England now. (as noted by d8veh they dont include cheap Chinese bikes available here).

I can set up my own test course and if I could have each bike I was interested in for a day or two I could try and compare, but unless I had pedal force meters and something equivalent to the instrumentation that Extra Energy have developed at the cost of 180,000 euros. I could not compare bikes using identical rider inputs from myself of different rides on different days.

So I am not very hopeful of determining the best puchase strategy based on hard data. Should I buy a cheap "Chinese" bike (rear wheel hub motor) and buy extra batteries as needed for range or a more expensive Panasonic type with a large battery?

Anyway, attached is my test route which I have been riding the last week on my push bike to get fit. If I can find a bike on which I can ride this 4 times at 10 mph ie about 3 hours overall, I will be satsified. When for my measuring application I very occasionally need to do more than 30 miles the route is likely not to have the steep hill which is around 11 -12 % on this test course.

The speed distance and altitude was recorded on my basic model Garmin eTrex, purchased two years ago for about £60. The data downloaded to GPSU Utility software on my PC. (No Iphones/Macs required!)

flecc · Jan 23, 2011

The Extra Energy tests are simply too easy and don't give a realistic or useful measure. This has always been their failing and their findings are very subjective and EU biased.

Yours is a good summary of the rider and other equalisation factors, excepting for the very personal preferences regarding the Panasonic type system versus the hub motor bikes. They really are so different that it is essential to try both types.

To answer your questions from my restricted knowledge:

1) Wisper 906 Alpino £1900
2) eZee Torq Alpine £1900
3) E-motion Sport Max + £1800
4) Kalkhoff Pro Connect Disc £1895
5) Alien Aurora £999

1) Which bike is fastest over the course? In order leaving out the Aurora: (2) if derestricted; (3) or (4) if the rear cassette is changed to give the maximum assist potential; (1) if derestricted. The Aurora could be the fastest of all but I do not know enough about it.

2) Which is quietest under power? (3) and (4) without doubt.

3) Ignoring price and other machines not listed here, which would you choose and why? Kalkhoff Pro Connect Disc, the reliability of the Panasonic system, the hill climb ability, the range potential and the bike quality. The E-motion a very close second but too outright sporting for me, personal taste of course. The Torq Alpine is also very good quality and very powerful but I'm a bit old for that type on the steeper hills.

4) Is there one which excels in hill climbing? (3) and (4) for me, since they drive through the gears so have the climb advantage of gear selection to suit the circumstances as motor vehicles do. However, if the hill gradients are average the Torq and Wisper could be faster up them, especially for a moderately fit cyclist. The Aurora would probably outclass the latter two for speed on average climbs but I can't confirm that with any certainty since I'm going by others subjective reports.
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BLACKPANTHER · Jan 23, 2011

indalo said:
My example scenario is a 20 mile round trip over a hilly route with no opportunity for battery top-up or change.

1) Which bike is fastest over the course?
2) Which is quietest under power?
3) Ignoring price and other machines not listed here, which would you choose and why?
4) Is there one which excels in hill climbing?

As an Aurora rider, I would love to have a head-to-head with riders of all the other bikes! Of course it wouldn't be a fair fight as it is an off road only bike.

Coincidentally, my commute is bang on 20 miles round trip. The Aurora will just make it to work and back on one charge using full assist, though I do recharge at work just to be on the safe side. It averages 20 mph, with next to no effort from me, which is pretty good going considering the traffic.

I have limited experience having only test ridden a wisper, but the Aurora isn't much louder. Price wise, I bought the Aurora just for fun really. I'm not bothered about pedalling only on an ebike as I have a regular bike I ride to work most days, so I just ride the Aurora when it's windy or if I'm a bit off it. If I'd been after an ebike to ride every day, maybe I'd have spent a bit more and gone for a more lightweight bike. Hill climbing? I can sum the Aurora up in 2 words, "WHAT HILLS?"

flecc · Jan 23, 2011

BLACKPANTHER said:
I'm not bothered about pedalling only on an ebike as I have a regular bike I ride to work most days, so I just ride the Aurora when it's windy or if I'm a bit off it. If I'd been after an ebike to ride every day, maybe I'd have spent a bit more and gone for a more lightweight bike. Hill climbing? I can sum the Aurora up in 2 words, "WHAT HILLS?"

This indicates just how subjective all such judgements are. Clearly BLACKPANTHER is a fit rider able to manage without an e-bike, very different from the majority of e-bikers who are mostly past their best cycling days. That includes me at 75, so i wouldn't be so confident on the Aurora's suitability for me, against a bike motor that drives through the gears so can enable even the weakest to climb the steepest hills, albeit slowly.

As all the most widely experienced members advise, it really is important for each prospective buyer to make the effort and travel if necessary to try the types under consideration. Only then can they be sure of getting it near to right for their unique self and circumstances.
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Deleted member 4366 · Jan 23, 2011

One point I noticed in the test results was that they didn't have any porky testers. I think 87kg was the heaviest. I think they might have been regular cyclists too. If all their riders had been 110kg and unfit, the results would probably have been very different.
Although they didn't test any cheap Chinese bikes, there was one with a rear 250w Bafang motor (Leviatech Argentic p 167, 167), who's results would probably be representative of similar bikes. It did very well on range, mainly because it had a bigger battery and they said it wasn't assisting all the time, but their data shows that it was assisting as much as most of the other bikes. A couple of other bikes had a front Bafang motor, but I think they were 24v. Regarding your question (10mph) about whether you could buy a cheap Chinese bike, I think the answer depends on whether you have the wherewithal to sort out any problems - should they arise. You save so much on the purchase price that you have enough money up your sleeve to buy/upgrade anything that goes wrong, but you need to do it yourself. If someone can't fix things themselves, then I think that they would best cross these bikes off their list. I'm not suggesting that things do go wrong, but if they do, it probably means a lot of hassle.

10mph · Jan 23, 2011

I think I could cope with fault diagnosis, although I might buy a nice digital test meter to measure battery voltages and currents. I hope I would not need an oscilloscope to look at the switching waveforms on the motor drive - may be I can get an a/d capture unit which will feed my PC.

I changed the brake blocks on my push bike yesterday, but I had to take the Shimano brake arms to the bike shop to get the worn out blocks off - I rounded the Allen key socket they were so corroded on. Years ago I used to overhaul my old car: top overhauls; even replacing cogs in gear boxes. A Chinese bike used for only a few hundred miles per year should be maintainable, especially with help and advice from the DIY specialists here, or else by googling.

At least repairing a bike I dont have to get my porky 90Kg on the ground to scrabble around underneath the thing.

clv101 · Jan 24, 2011

Doesn't A to B magazine test electric bikes on a standard course?

flecc · Jan 24, 2011

indalo said:
Other than anecdotal evidence, I think most readers really won't have any idea just how good, bad or indifferent the selection of bikes I suggested are in the real world and that is the problem.

Of all our members, Aldby is the most experienced in every factor of ownership of different e-bike types, since he has bought, owned, used and sold an extraordinary variety of models and makes. His clearly expressed preferences are the eZee models for their character and quality, and the Kalkhoff models with the Panasonic units. His favourite owned models for a long time now are an eZee Forza and a Kalkhoff Pro Connect S. He lives in moderate territory at Milton Keynes so that gives a good idea of circumstances for others to judge from.

indalo said:
When I think of horse-racing, there are, ostensibly, certain measures practised to level the playing field, so to speak. Weight handicapping plays a large part as do age parameters, (of the horses!) In some regards, horse and jockey are very similar to bike and rider so, for me, a little more factual and demonstrably fair, comparative material on the various aspects of ebike ownership and usage would be desirable.

Weight is the biggest of all factors making comparative e-bike testing extremely difficult to carry out in a useful way. The average car will be only slightly affected by the difference between an 8 stone man and a 20 stone one, and we have both in our membership, but the power-to-weight ratio difference of those two cases on any e-bike makes any performance comparison useless. The second factor often making test reports useless is terrain, in this case the power-to-gradient difference requirements which are equally extreme when the power is so limited in the first place. And of course the third factor is the vast difference between rider abilities in the mainstream population. These range from the ability to sustain 200 watt pedalling output for hours on end with five minute peaks of 300 watts, to a maximum of 100 watts for short periods and only 50 watts sustained long term.

indalo said:
The Panasonic system is pretty quiet and seamless in operation so I suspect that the day is not far off when we will see those machines offered with "strictly off-road mode". After all, 0-60mph & top speed are everything for the masses; not emissions, fuel economy, etc......right?

The nearest to this has been the off-road Panasonic powered BikeTec Flyer X model, 300 watts and larger battery, though there are some roadster 300 watt versions now from more than one manufacturer. We probably won't see much more power due to the limitations of bicycle transmissions, hub gears already fail at times with the combined power of the present system when a strong rider output is added and Shimano's 4 speed hub was discontinued for this very reason. The Cyclone kit units are usable with high powers but are normally used with derailleurs where the penalty is mainly high wear rather than sudden failure.
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10mph · Jan 24, 2011

flecc said:
Weight is the biggest of all factors making comparative e-bike testing extremely difficult to carry out in a useful way. The average car will be only slightly affected by the difference between an 8 stone man and a 20 stone one, and we have both in our membership, but the power-to-weight ratio difference of those two cases on any e-bike makes any performance comparison useless. The second factor often making test reports useless is terrain, in this case the power-to-gradient difference requirements which are equally extreme when the power is so limited in the first place. And of course the third factor is the vast difference between rider abilities in the mainstream population. These range from the ability to sustain 200 watt pedalling output for hours on end with five minute peaks of 300 watts, to a maximum of 100 watts for short periods and only 50 watts sustained long term.

Of these variables, Rider Weight is easy to measure, so all performance tests/claims should have rider weight quoted.

Terrain needs a little more work to determine from maps or Google-Earth, and also its link with average speed or range is rather complex, nevertheless if we are told just the average gradient and length hills on a test route it would help.

Rider input could be determined in the same way as the ExtraEnergy Tests. Multiply the output of the pedal force sensor by the crank speed with a suitable calibration factor (depends on crank length). Thus the tester could determine the average watts put into the pedals by the rider during the test - so at least we can see whether one test has a fit rider working hard, and in another test the rider has taken it easy and has relied more on the motor.

Hill performance ought to be be fairly to pin down with these measurements. For example, I might read in a test report that a 50Kg rider on a 20kg bike can ride a 10% hill at 10mph putting in 100 watts with about 200 watts from the motor, I can calculate that if I put a 100kg rider producing the same power on the bike, he will only achieve 10mph on a 5.8% hill. If the test rider had runs at different speeds and powers then there would be data I could match to my likely capabalities. Also I could see exactly how one bike compares with another in respect of hill climbing,

It does get a lot more complicated at speeds on the flat where air resistance becomes important, and where the power cutoff to stop the speed exceeding 15mph may also be relevant. However, it would be a start if had test rider's weight and average power during the test.

flecc · Jan 24, 2011

10mph said:
Rider input could be determined in the same way as the ExtraEnergy Tests. Multiply the output of the pedal force sensor by the crank speed with a suitable calibration factor (depends on crank length). Thus the tester could determine the average watts put into the pedals by the rider during the test

So they say.

How do they do this when the Panasonic and Yamaha units amongst others have the torque sensor inside the sealed unit with no access whatsoever to their connections or outputs? I remain cynical about ExtraEnergy's tests since some of their results I know from first hand experience have been rubbish, and the Euro-centric bias is blatant.

Regarding the inclusion of all relevant factors when testing and reviewing, I attempted this when I carried out the test and review on the original Kalkhoff Agattu. As you'll see from the link, I included my own factors, the weather conditions and temperatures, and the terrain by both comment and Sanoodi link. Unfortunately since then the Sanoodi links have lost some of the old and much better gradient indicators, but they are still useful. Scroll half way down for the circumstances and to the head of each day ride for the conditions.

While it's true that you could work out the relevance to you of the test factors you suggest, the great majority of all e-bike purchasers could not, they simply don't have the relevant knowledge and experience. Which begs the question, is it worth bothering when the majority would neither appreciate or make use of the information? Personally I can't see any test source bothering now or in the future. I'd bet only a couple of percent or less of e-bike buyers have ever seen the ExtraEnergy site or perhaps even heard of it, such is the lack of demand for detailed information.

Kalkhoff Agattu review and test
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10mph · Jan 24, 2011

flecc,
ExtraEnergy say they fit a pedal containing a strain guage to provide torque sensing for their test data.

If the Panasonic torque sensors are sealed, presumably one could in principle get at the rider torque signal where it reaches the controller, since in the control this signal is used to adjust the power to the motor. Indeed if the system is exactly as you describe and in the Kalkhoff literature where I have read the controller arranges for a fixed factor of the measured rider torque to be added by the motor, then measuring motor power (Volts and amps with meter) would give a handle on rider power. For this system then perhaps you dont need to take any measurements, just calculate how many watts total you need to climb the gradient at a given speed and then see if any of the Panasonics power settings will multiply your own power capability enough to get you up the hill at that speed.

I get the impression that is how you did some of the rider power calculations in your report. By the way it is a really excellent example of a test report. I read it in November and it convinced me that the Kalkhoff Aggatu would suit my application and rider power capability. It is good to be reminded and to go back and study it again now. I have had one short test ride on a 7 speed model. I am hoping to have a more extended test ride on the latest 3 speed model very shortly. I want to make sure that the three gears suit me, and whether I will need a sproket change.

Rider power sensors used by serious cyclists are very expensive - I have just found a very nice review "An engineer's perspective" at Power Meter Review.

It is a very fair point you make about the majority of bike users not being able to make use of rather abstract numerical data. But I think it is a question about how the data is presented, and what simple tools are provided to do the comparisons and calculations. If you have the basic data about a system, it is trivial to make an online calculator so the average user does not have to worry about calculations. eg the famous Sheldon Brown's Bicycle Gear Calculator

I note with interest your reservations about the ExtraEnergy tests. Overall I was very impressed with the work they put in, and their detailed explanations of their procedures & data analysis. I do admit that I thought that it seemed an almost model example of how bikes should be tested alongside one another, albeit that their analysis method is limited because they did not normalise out the rider variables in the most useful way - at least for me as a physicist and the other minority here (but a vocal one!) - engineers.

mechaniker · Jan 24, 2011

i agree with flecc for 100%,

extra-energy is a good start for the first look on e-ike but i would more like hard fact´s and not so much subjective meaning.
Also you must notice how extra-energy finance there test´s ;-)
Understand right, i like the work of extra-energy but i think it would be better to have a real independent Organisation because at time a producer must pay the test and he can took away his bike when the result dont look well to him and you also must realise that extra-energy need producers for the test. So i see a conflict in this way of testing because if they would write to much bad about the bike´s , next time no company would make the test.

I think it is time that some relly independent group of engineer´s create a real test for e-bike motors. No meaning, only fact´s!!
No different riders, only robot´s as riders with different power and different terrain, so that every user find himself in the test.

Even if the people must pay for to see the test-result , so what, not everything can be for free and it should be in buyer´s interest to pay some money for a real honest test.
A ebike buyer spend between 500-4000 for a e-bike, if he spend 10-20 in honest test-result´s it is´nt to much.

and as a second point read the extra-energy magacine, why not? you never can have to much input.

Then you have to make a testride by your own

and after all is done you should know wich bike is your´s ;-)

have a good day
frank

Streethawk · Jan 25, 2011

With a higher end digital turbo trainer, a heart rate monitor and a bike computer with cadence and speed you could get some fairly consistent results. Of course thats very much not "real world" though.

And i suspect you might struggle to fit rear hub motor bikes on the trainer which usually attached to QR dropouts...

Who wins in real world use?

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