Is my Kalkhoff performing right?

[Barry Edwards]

Hi new member here, background info is i am 56 and recovering from a triple heart bi-pass 12 months ago. Having owned 2 Chinese e-bikes over the last year, firstly a cyclamatic (24v 18 gear rear hub motor) lasted about 7 months then died, was refunded by Amazon, great idea poor build! then bought a Cyclotricity (36v rear hub motor 24 gear)(advertised as a Claude Butler bike) it wasn't, i still have it but the battery dies after 10 mile, and again the build is poor, so i just bought a low mileage mint condition Kalkhoff Agattu 7G, now it feels much more solid and superior build quality you would expect from a German bike 3 times the cost of the others but it does seem harder ie more effort to ride, apart from the fact i can hardly here the motor, it seems to make little difference weather in 1 2 or 3 mode certainly unlike the response from my Cyclotricity that will spin the front wheel if starting on a hill in high, my partner who is 15 years younger and rides a light hybrid tried it and says there is a big difference so is it me just not used to a crank drive? or is there something wrong with it, how can i tell or test it, the others had an additional throttle mode which lets you test the motors spinning.
In 2 trips the battery lasted well and covered about 35 miles from 1 charge, any advise would be depreciated, thanks Barry

 

[D8ve]

You do forget what unpowered cycling is like.
Best try some runs with no power and then low mid high and see how the acceleration and hill climbing changes.
If it is only 250 watt it will feel a lot less than a high power hub drive but much less range for the battery.

 

[flecc]

The unit's power is derived from the torque sensor pressure, so only high pedal pressure gets the maximum power. This is true in all power modes. Also, if the Agattu is early 2010 or before, it will have the early power phase down starting at 9.4 mph. From there upwards the power in all modes diminishes in a roughly linear fashion, less that half by 13 mph and gone at just over 14.5 mph.

 

[Barry Edwards]

The unit's power is derived from the torque sensor pressure, so only high pedal pressure gets the maximum power. This is true in all power modes. Also, if the Agattu is early 2010 or before, it will have the early power phase down starting at 9.4 mph. From there upwards the power in all modes diminishes in a roughly linear fashion, less that half by 13 mph and gone at just over 14.5 mph.

Thanks for your reply s, i meant appreciated by the way not depreciated, Flecc i understand what your saying but i dont now get that kick like with the hub motor,which you could really feel working, more short spasmodic thrusts when plying peddle pressure, is the torque sensor adjustable to give just a we bit moreor could it be faulty? as i am struggling on steep hills, i didnt struggle on before, it is a early 2009 Agattu 7g ido love the look and feel of the bike just disappointed by the effort needed compared with either of the hub drives, flecc how can i make it better can it be de-restricted maybe?

 

[halfer]

If I were you, I'd look into where my local Kalkhoff dealers were based, and see if the bike could be taken in. I doubt asking someone to try the bike on the road for two minutes would be chargeable - and they would be able to provide the voice of experience.

If there is a problem, they will be able to advise on chargeable work.

Also, do you shift down gears when tackling a hill? Even the most powerful crank drive bikes need to be put in an appropriate gear, so the motor is not given too much work to do.

 

[Barry Edwards]

If I were you, I'd look into where my local Kalkhoff dealers were based, and see if the bike could be taken in. I doubt asking someone to try the bike on the road for two minutes would be chargeable - and they would be able to provide the voice of experience.

If there is a problem, they will be able to advise on chargeable work.

Also, do you shift down gears when tackling a hill? Even the most powerful crank drive bikes need to be put in an appropriate gear, so the motor is not given too much work to do.

Hi yes I have tried various combination of gears. 3rd seems to be best maintaining a constant crank ratio seems to give the most assist but obviously very steep hills a lot of effort is required to stay in 3rd! I would love to have a pro look at it I am in Plymouth don't think there is any where close by, but will check thanks maybe someone has one close by and would let me try there's and compare

 

[halfer]

Aha, these people are not far from you (50 miles or so), and they do Kalkhoffs

http://www.bikehigher.co.uk/buy-an-electric-bike

 

[Deleted member 4366]

I don't think that there's anything wrong with it. They're not very powerful compared with a 36v hub-motor. I found exactly the same as you when I tried one. You have to use all the gears to make use of the limited power, which means going right down to first on steep hills. All the 36v crank-drives have a lot more power.

 

[tillson]

I'm surprised that you are finding that the bike has very little power. This Panasonic unit uses the motor output shaft to measure speed and hence the motor cut off point. So in effect, it's how fast you turn the pedals, or pedal cadence, which determines the point at which the motor cuts, not the road speed. On the older units, the cadence at which the motor starts to phase down, or even cut, can feel unnaturally low to some people and they tend to pedal through the assist band and out of the top, leaving them with no assistance. The trick is to keep the pedal cadence in the maximum power band, which to some can feel a bit awkward. The pulsing which you describe makes me think that you have pedalled through the power band and out of the top. Your speed then starts to drop due to the assistance falling away and you drop back into the power band giving the pulse effect as you bounce in and out of assistance.

My experience of riding a Panasonic powered bike, and I have a lot, is that it has a good deal of power, sufficient to tackle most hills that you are likely to encounter. Try pedalling slower and changing up earlier.

 

[Deleted member 4366]

He's doing the opposite. He's pedalling so slow that each time he presses the pedal on the down-stroke, he can feel the motor responding to the torque. If anything, he needs to pedal faster in a lower gear.

 

[mike killay]

Why on earth do manufacturers bother with these quirky systems?

 

[flecc]

Thanks for your reply s, i meant appreciated by the way not depreciated, Flecc i understand what your saying but i dont now get that kick like with the hub motor,which you could really feel working, more short spasmodic thrusts when plying peddle pressure, is the torque sensor adjustable to give just a we bit moreor could it be faulty? as i am struggling on steep hills, i didnt struggle on before, it is a early 2009 Agattu 7g ido love the look and feel of the bike just disappointed by the effort needed compared with either of the hub drives, flecc how can i make it better can it be de-restricted maybe?

As others have said Barry, that is normal. The motor operates in almost servo fashion, responding to each crank pressure stroke, basically multiplying your muscle input. It doesn't run continuously motor vehicle fashion in the way a hub motor does.

Pedalling at 40 rpm is the best combination to get maximum power with as best smoothness possible, but the pulses will still be felt. Pedalling faster smooths them out but also gives less power, the faster the rotation, the less the power.

That's just the character of the design, true to cycling principles and not in any way like a motor vehicle, and it cannot be altered. This is a major reason why we say always try before buying, since hub and crank motors are very different, and some more different than others.

Which is preferred is a Marmite thing, love or hate.

 

[flecc]

Why on earth do manufacturers bother with these quirky systems?

Answer above, they were keeping it exactly like a bicycle, just multiplying the pedal stroke power. The unfortunate thing is the early power reduction since the Japanese regard 15kph (9.4mph) as a normal cycling speed so that reduction is the law there. This might be acceptable in Holland, but in the UK where cycling is thought of as sporting, it's laughable of course.

From 2010 onwards Panasonic recognised that and altered the system to allow full power to 25 kph (15.6mph) on export units.

 

[mike killay]

Thanks Flecc,
I guess that it just poles apart from what I want from an electric bike.

 

[Barry Edwards]

Ok thanks guys for all your advise at least i know its not broken, just a completely different ride altogether than a hub motor, i will put aside my 36v cyclotricity for the next 2 weeks and concentrate solely on the Kalkoff and see if i can master it, using your recommendations, changing between the two is not helping at all!
I did call 50 cycles who didn't help me much said they couldn't comment without seeing it, well there a long way from Plymouth so that wont be happening, Thanks halfer for finding the Torrrington shop we will take a trip up there in the camper one weekend soon and check with those guys and the great rides around north devon coast, (thats if i can peddle this thing properly by then lol) i hope so but have a funny feeling it might be back on eBay and me back on the hub!! thanks again all!!!

 

[trex]

you'll like the pedelec torque sensor system more in a week. It may not suit everyone but the system has great advantages: reliable and long lasting motor and electronics and help you keep your legs strong. The motor and electronics cannot be overloaded, so they go on for many years totally trouble free.

 

[Chris the Sheep]

I agree with some other posters - you're probably pedalling slowly in a high gear, change down so that you're pedalling a bit faster and more smoothly.
My Giant does much the same; I think its software tries to smooth out the pedal strokes to give a constant level of assistance, but it struggles below a certain cadence and can give the impression of cutting out. My bike has a hub motor so I don't think it's a feature of crank drives specifically, more a torque-sensor / software thing.

(The same advice applies to conventional cycling too - it's far more efficient to change down than 'mash' a high gear)

 

[Jonah]

Ok thanks guys for all your advise at least i know its not broken, just a completely different ride altogether than a hub motor, i will put aside my 36v cyclotricity for the next 2 weeks and concentrate solely on the Kalkoff and see if i can master it, using your recommendations, changing between the two is not helping at all!
I did call 50 cycles who didn't help me much said they couldn't comment without seeing it, well there a long way from Plymouth so that wont be happening, Thanks halfer for finding the Torrrington shop we will take a trip up there in the camper one weekend soon and check with those guys and the great rides around north devon coast, (thats if i can peddle this thing properly by then lol) i hope so but have a funny feeling it might be back on eBay and me back on the hub!! thanks again all!!!

Barry,

You'd be most welcome to drop in one weekend. We can try your bike out to check for normal operation and let you try out some others for comparison if you want too. Best to let me know in advance so I can make sure I am around. You can PM me on here or email me via http://www.bikehigher.co.uk/contact