26V 18Ah Kalkhoff vs 36A 16Ah Wisper

[brucehawsker]

Been lookikng at boats in the summer but just came back to the forum and noticed the new Kalkhoff battery...

Just a piece of curiosity? One for Flecc certainly

26V x 18Ah gives a Wh of 468

36V x 16Ah gives a Wh of 576

That means the Wisper goes further. Am I right?

But is it the case that the 36V always will give better acceleration than 26V as well? Or am I being simplistic comparing hub motors with the cranks?

Thank you.

Bruce

 

[flecc]

No. The Wisper hub motor has a peak power of 550 watts, the Kalkhoff one 400 watts, so ranges will be similar in theory but better on that 18 Ah equipped Kalkhoff in practice.

Since hub motors as on the Wisper do not have the advantage of driving through the gears, they have to be a bit more powerful to cope with steep hills.

Although in theory the voltage need not make any power difference since designs can allow for that by increasing current in lieu on the lower voltage ones, in practice the 36 volt ones tend to be more powerful for practical design reasons.
.

 

[brucehawsker]

Thank you oh guru.

Can I probe just a tad deeper?

If the Wh were the same on both batteries, would you expect the ranges to be the same? But because the Wisper draws more due to the higher wattage, if the Wh were the same, you would expect the Kalkhoff to have a longer range.

1. About what % impact on the range does the need for that hub motor to be more powerful at peak have?
2. Is it the case, then, that 26V crank bikes are generally just as capable of hill climbing and pulling away smartish from the lights as 36V hubs?

 

[tangent]

I find it difficult to imagine why anyone would want a battery of higher capacity than 18Ah on a Kalkhoff. My bike does at least 20 miles on a 10Ah battery and that is making profilgate use of the battery - e.g. on all the time with a bike overgeared for speed. If I had an 18Ah battery I would expect at least 40 miles range the way I ride the bike. However, if I had to go 40 miles somewhere before I could recharge I would probably take the car instead.

 

[flecc]

Thank you oh guru.

Can I probe just a tad deeper?

If the Wh were the same on both batteries, would you expect the ranges to be the same? But because the Wisper draws more due to the higher wattage, if the Wh were the same, you would expect the Kalkhoff to have a longer range.

1. About what % impact on the range does the need for that hub motor to be more powerful at peak have?
2. Is it the case, then, that 26V crank bikes are generally just as capable of hill climbing and pulling away smartish from the lights as 36V hubs?

Yes, the Kalkhoff in standard trim will have a longer range, quite substantially so in fact. It's range on a standard 265 Wh (10 Ah) battery is about 30 miles for most riders. The Wisper on the present standard 518 Wh (14 Ah) is about 45 miles.

This really answers your question (1) in bold print, but it's impossible to give a specific percentage. The rider variables affect the position too much for that.

2) Crank drives are actually more capable of climbing the much steeper hills due to gear selection advantage, but they do it slower in lower gears of course. Hub motors are effectively in top gear all the time which is not ideal for steep hills. When the hills are more gentle, the powerful hub motor bike can have the advantage through greater uphill speed with it's motor at a more optimum power point than when it's slogging slowly up a steeper one. The crank drive is better for the latter since by gear selection the motor stays at it's more limited optimum power all the time.

Pulling away from the lights brings in all sorts of different factors. By deisgn the Panasonic system is very good at that initially and with the same rider effort is probably best just for a few yards.

P.S. Just to complicate things, many riders gear up the Kalkhoffs to get assistance to higher than legal speeds. This reduces the range of course, the reduction amount depending on the degree of gearing up and assist speed limit gain.
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[eddieo]

There is to be a 12 amp Panasonic battery? If this is correct surely it would be a better balance of cost V weight V expense...unless you want to go touring etc....

I am very excited re the 250watt 36 volt Bosch system and hope it will be the one to beat

But do crank drives put more strain on dérailleur gears? as I have seen some chat regards this, also that gear changing being slightly problematic on a Panasonic.....

 

[Kenny]

The crank drive obviously transfers a fair bit of power through the cogs but probably no more than a strong Club rider does. As for the gear change, it's no different from an unpowered bike. Just make sure you ease off the pressure through the pedals while shifting and it's very smooth.

 

[eddieo]

The crank drive obviously transfers a fair bit of power through the cogs but probably no more than a strong Club rider does. As for the gear change, it's no different from an unpowered bike. Just make sure you ease off the pressure through the pedals while shifting and it's very smooth.

Thanks Kenny...The flyer S XT I tried this week was great to shift, some of the other models not as good, very notchy gears, but I probably did not understand it. while I have your attention, what are the differences with the "S" model Kalkhoff please

 

[HarryB]

As I said in a previous post the panasonics are harder on the gears than hub motored bikes. A rider on a biclycle (whether at club level or not) has absolute control over how much power goes to the gears but this is not so with the panasonic powered bikes as you are controlling another motor. There is for example a delay in the power coming off and this makes it more difficult to get the changes spot on. I have done 500 miles and am still getting used to how much to back off, mostly I get it right but occasionally I still get it wrong and it sounds horrible. I don't think it is much of a problem, especially for those who are not commuting in heavy traffic. But it is just something else that needs to be got used to.

 

[Kenny]

There is for example a delay in the power coming off and this makes it more difficult to get the changes spot on. I have done 500 miles and am still getting used to how much to back off, mostly I get it right but occasionally I still get it wrong and it sounds horrible. I don't think it is much of a problem, especially for those who are not commuting in heavy traffic. But it is just something else that needs to be got used to.[/QUOTE]

I agree with this Harry, I occasionally get it wrong too and and suffer the dreaded "crunch" It's very rare though and it's never caused any damage. I've also noticed some people I cycle with never seem to get the hang of it!

Eddieo, The main difference between the Pro Connect and S model is that The S delivers power up to about 21 mph as opposed to the standard bikes (legal) 15 mph. It's also a slightly better spec-ed bike in a number of areas ie. lights, tyres and brakes.

 

[eddieo]

Eddieo, The main difference between the Pro Connect and S model is that The S delivers power up to about 21 mph as opposed to the standard bikes (legal) 15 mph. It's also a slightly better spec-ed bike in a number of areas ie. lights, tyres and brakes.

is this higher speed achieved by changing just the rear cog?

If yes, can this be done on any panasonic bike...also does hill climbing suffer if top speed increases.....

 

[Kenny]

I think the higher speed of the Pro Connect S is achieved by changing the crank motor drive sprocket from a 9 tooth to a 11 tooth.
The rear cluster on the Pro Connect S's derailleur gears has 9 cogs.
I think you are confusing this with the Alfine gears on the Pro Connect where the single rear drive sprocket is replaced with one with less teeth to achieve the speed increase.

 

[flecc]

The Kalkhoff Panasonic powered S models also have a bit more power plus more power in the high power mode, it's not just done by gearing.

The top assist is indeed about 21 mph for the 9 speed derailleur, but the model with the SRAM Dual Drive has assistance to about 26 mph.

The same goes for the equivalent BikeTec Flyer models
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[brucehawsker]

Still trying to get my mind round this - sorry. My question had better revert to the real world.

What do you guys (and gals sorry) think the real world expereince would be of a rider who is 14 stone, 6ft, with a laptop and a couple of big lever arches in the panniers, with modest hills (near to Dorchester, Dorset), with a full charge on a Kalkhoff 18Ah and a full charge on a Wisper 16Ah.

The rider is a bloke who has never been a fitness freak or a keen cyclist, but who commutes a couple of times a week on average on his bike 18 miles eash way. He pedals modestly! He decides to set off on a sunny Saturday and see how far he can get across the Dorset hilly countryside. No heavy duty pedalling - a relaxed long jaunt.

Would he get:

a) approximately the same mileage from each bike?
b) far more from the Kalkhof?
c) far less from the Kalkhof?

Would he be sweatier after the ride on the Wisper or the Kalhof? Wouldhe feel subjectively tireder on the Kalkhof?

 

[carpetbagger]

the kalkhoff would do it easy with no in between charge.
you have the option not be as sweaty on the wisper...throttle only if required but i don't know if it would do the full return journey....but it may be sunny but a big factor is the wind......you should get a lot further on the kalkhoff.
you wouldn't necesarily be more tired on either bike.......in my opnion

 

[flecc]

The hills near Dorchester aren't very steep on the whole, mainly just rolling countryside. The Wisper will probably mean less work for the rider most of the rime but more work on any much steeper hill met. It should do the 36 miles round trip with a moderately fit rider on the old 14 Ah batery, so on the 16 Ah it should be ok.

The Kalkhoff will mean a little more work all the time since the power is given as a ratio of cyclist input, but it's range with 18 Ah will probably allow two of the 36 mile round trips. That means the bike could be left on high power mode all the time to reduce the rider work input, with the range still well over what's needed.
.

 

[brucehawsker]

Sorry, did not make myself clear. Forget the 36 mile round trip. The issue is which bike would go the furthest and how the guinea pig would feel after the journey!

 

[flecc]

The Kalkhoff would go the furthest by far, but it wouldn't be the most comfortable if you used the standard Pro Connect model. You'd need either an Agattu or a Tasman model for the best comfort, both having sprung forks and seatpost with a forgiving frame.
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