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Ongoing reliability of Kalkhoff/Focus Impulse 2 motors

Apr 28, 2015
388
36
43
#1
Hi,

I am trying to ascertain who is having issues with Impulse II motors on Kalkhoff or Focus e-bikes (both made by Derby Cycles).

Personally, I had a first motor replacement after 900 miles (4 months, loud clacking/clicking noise), and then another failure at around 900 miles (7 months, very weak assistance, some loud clacking once).

I have found the following people reporting issues too on this forum (usually on fairly new pedelec bikes and low mileage/kilometers):

Username/Model/Age/Mileage
reggie_electric - Agattu - 6 months - 800km
nemesis - Focus Jarifa - 4 months - ???
Jean-christophe Saville - S11 Alfine - 14 months - 2800 miles
Lothlean - ??? - 10 months - ??
Will Tinker - Pro Connect 9 - 5 months - 500 miles
Oriteroom - Focus Aventura Impulse S10 - 10 months - 3000 miles (3rd motor)
Roger R - ??? - 6 months - 1000 miles
nightrider - Endeavour S10 - ?? - ??
bernharvey - Agattu - ?? - 400 miles
Reseg - Focus Aventura - 10 months - ?? (3rd Motor)
lowranger - Impulse 10 - ?? - 2300 miles
Biscitt - Agattu - ?? - 350 miles
Biscitt - Tasman - ?? - 100 miles
Tomtomato - Pro Connect 10 - 7 months 900 miles (2nd fault)

Please reply to this thread if you had a motor issue.

It seems quite clear to me that there is a design/quality issue with the Impulse 2 crank-driven motors, and that those should be able to last a lot longer (given the high prices of the bikes), without requiring some expensive replacements (£600, once out of warranty). Kalkhoff are not willing to provide a warranty beyond 2 years on those motors, and have made people pay for replacement out of warranty, even when low mileage was done.

After first saying that there were no issues, they confirmed that Kalkhoff knew about the issue, and it had been sorted. A software update can apparently prevent some clacking issues leading to failure. However, I am not aware of a recall to do so by Kalkhoff (are they just waiting for bikes to fail?).

The 2015 motor replacement I had (supposedly the new reliable version) failed again after a small mileage, so I am not sure the issue is really sorted.

Thanks,
T.
 
Last edited:

nemesis

Pedelecer
Mar 14, 2011
507
52
43
#2
The impulse 2 motor performs very well and has more power than the rivals plus the batteries are high range but sadly reliability leaves a lot to be desired.I am now on my second motor and in the meantime have been riding a bosch cx motored cube bike that feels weak compared to the impulse but maybe that will make it more reliable in the long run.
Why did kalkhoff ever stop using the panasonic motor,it must have been because of profit.
 

tillson

Pedelecer
May 29, 2008
5,044
138
113
#3
Why did kalkhoff ever stop using the panasonic motor,it must have been because of profit.
I know Kalkhoff bought out a motor manufacturer called Daum a few years ago and now brand that motor as Impulse. Presumably this allows them to reduce the motor cost element of producing an ebike. All done without passing any of the savings on to the customer of course, so yes, they dumped the excellent Panasonic motor in pursuit of greater profits.

It looks like this decision has reared up and bitten them on the ar$e with all of these failures. It seems to be pretty conclusive that anything more than light occasional use is going to result in a failure of the motor. They will never ever admit to this and the strategy will be to shovel all financial respondibility for long term replacements onto the customer.

Some customers have had 2 to 3 replacements under warranty which I think indicates that the motor has an intrinsic weakness or fault making it unfit for purpose.

My old Panasonic powered Kalkhoff (second motor 24000 miles) is still going strong and I would not swap it for a new impulse powered Kalkhoff.

Incidentally, whilst on a recent trip to Swizerland I saw several new looking Flyer bikes, they seem to be using the Panasonic or Bosch motors.
 

Croxden

Pedelecer
Jan 26, 2013
2,014
94
113
North Staffs
#4
What are they in business for if not to make profit, bikes are of a secondary importance.
 

nemesis

Pedelecer
Mar 14, 2011
507
52
43
#5
What are they in business for if not to make profit, bikes are of a secondary importance.
Yes profit is important in business but you must have a reliable product for customers to use.
 
May 26, 2008
818
43
43
#6
You can only base a successful long term business on a good reputation and return custom/recommendation.
 
Apr 28, 2015
388
36
43
#7
What are they in business for if not to make profit, bikes are of a secondary importance.
Yes indeed, profits are important. I reckon 50 Cycles make about 45% margin on a Pro Connect 10 bike, sold for £2300. Therefore, people would also expect some good after sale service for that price.

For instance, the first 100 miles service/check was not even included in that price. The shop didn't charge me for it, but said I was lucky not have paid the £50 charge... For some reasons, I can buy a bike from Hallfords or Evans Cycle for £200, and get a free first 6-week check...
 

nightrider

Finding my (electric) wheels
Sep 11, 2014
34
10
8
64
#8
Hi,

I am trying to ascertain who is having issues with Impulse II motors on Kalkhoff or Focus e-bikes (both made by Derby Cycles).

Personally, I had a first motor replacement after 900 miles (4 months, loud clacking/clicking noise), and then another failure at around 900 miles (7 months, very weak assistance, some loud clacking once).

I have found the following people reporting issues too on this forum (usually on fairly new pedelec bikes and low mileage/kilometers):

Username/Model/Age/Mileage
reggie_electric - Agattu - 6 months - 800km
nemesis - Focus Jarifa - 4 months - ???
Jean-christophe Saville - S11 Alfine - 14 months - 2800 miles
Lothlean - ??? - 10 months - ??
Will Tinker - Pro Connect 9 - 5 months - 500 miles
Oriteroom - Focus Aventura Impulse S10 - 10 months - 3000 miles (3rd motor)
Roger R - ??? - 6 months - 1000 miles
nightrider - Endeavour S10 - ?? - ??
bernharvey - Agattu - ?? - 400 miles
Reseg - Focus Aventura - 10 months - ?? (3rd Motor)
lowranger - Impulse 10 - ?? - 2300 miles
Biscitt - Agattu - ?? - 350 miles
Biscitt - Tasman - ?? - 100 miles
Tomtomato - Pro Connect 10 - 7 months 900 miles (2nd fault)

Please reply to this thread if you had a motor issue.

It seems quite clear to me that there is a design/quality issue with the Impulse 2 crank-driven motors, and that those should be able to last a lot longer (given the high prices of the bikes), without requiring some expensive replacements (£600, once out of warranty). Kalkhoff are not willing to provide a warranty beyond 2 years on those motors, and have made people pay for replacement out of warranty, even when low mileage was done.

After first saying that there were no issues, they confirmed that Kalkhoff knew about the issue, and it had been sorted. A software update can apparently prevent some clacking issues leading to failure. However, I am not aware of a recall to do so by Kalkhoff (are they just waiting for bikes to fail?).

The 2015 motor replacement I had (supposedly the new reliable version) failed again after a small mileage, so I am not sure the issue is really sorted.

Thanks,
T.
I thought 50 cycles were going to agree to honour after warranty impulse 2 motors as stated in previous posts couple of months ago, this will have to be verified.
 

nemesis

Pedelecer
Mar 14, 2011
507
52
43
#9
The 2016 impulse motor has a good reliabilty record so the issues with the previous versions must have been resolved.
 

nemesis

Pedelecer
Mar 14, 2011
507
52
43
#11
We are only 5 1/2 months into 2016?
The 2016 year model was released to buy in august 2015 in europe and the first ones were in the uk in november,i know because i had one but sold it because i prefered the mtb i already had.
It would be worth having a look on the german forums to see if any failures have occured with the latest motor.
 
Apr 28, 2015
388
36
43
#12
I thought 50 cycles were going to agree to honour after warranty impulse 2 motors as stated in previous posts couple of months ago, this will have to be verified.
I have asked them if they could put in writing that the motor would be guaranteed for x years or x miles, and they wouldn't. I also know that some people have been charged for motor replacements out of warranty, despite low mileage done.

I guess Kalkhoff would only provide them with free replacements for the first 2 years anyway, and then they would have to bear the cost themselves.
 
Apr 28, 2015
388
36
43
#13
The 2016 impulse motor has a good reliabilty record so the issues with the previous versions must have been resolved.
How do you know that?

If you are you talking about the Impulse Evo, then it wouldn't be much reassurance for people who have spent thousands of pounds on a bike with an Impulse 2 motor, who could be facing several trips to the shop during warranty for motor replacements, and then £600 cost once warranty is over.

Regarding the Impulse Evo, Kalkhoff does mention "numerous improvements", "Stronger gear", "Additional cadence sensor"...
 
Jun 30, 2014
234
25
43
60
Kent
#14
Strange as 50 Cycles is a sponsor/business user on this website and yet no defence,no comment,no words not even a murmur which if you read into this thread makes you wonder why isn't he defending his product/products.:eek:
 

nemesis

Pedelecer
Mar 14, 2011
507
52
43
#15
How do you know that?

If you are you talking about the Impulse Evo, then it wouldn't be much reassurance for people who have spent thousands of pounds on a bike with an Impulse 2 motor, who could be facing several trips to the shop during warranty for motor replacements, and then £600 cost once warranty is over.

Regarding the Impulse Evo, Kalkhoff does mention "numerous improvements", "Stronger gear", "Additional cadence sensor"...
Yes the new 2016 evo motor,there doesn`t look like any have failed because i can`t find reference to any failures.It could be that the new internals have worked.
 
Sep 24, 2007
870
15
28
#16
Strange as 50 Cycles is a sponsor/business user on this website and yet no defence,no comment,no words not even a murmur which if you read into this thread makes you wonder why isn't he defending his product/products.:eek:
I have noticed 50 cycles are now selling other electric bikes,maybe they are getting ready to abandon ship again.
 
Apr 28, 2015
388
36
43
#17
Yes the new 2016 evo motor,there doesn`t look like any have failed because i can`t find reference to any failures.It could be that the new internals have worked.
Actually, there are a few failures already reported on various forums, but it may not be for the same reasons.

The new 2016 Evo motor is also only available on a few high price bikes.

I believe Kalkhoff are still selling bikes with the Impulse 2 motor, even though they are aware of design flaws and repeat breakdowns/failures. They seemed to have changed the software to reduce the strain on the motor (read: throttle down assistance) in certain conditions, but I don't believe the flawed mechanical components have been changed.
 
Oct 25, 2006
40,227
186
113
#18
I believe Kalkhoff are still selling bikes with the Impulse 2 motor, even though they are aware of design flaws and repeat breakdowns/failures. They seemed to have changed the software to reduce the strain on the motor (read: throttle down assistance) in certain conditions, but I don't believe the flawed mechanical components have been changed.
I'm not so sure they were flawed components. The troublesome gear was perfectly ok in the Impulse 1. It was only the power race they entered into with the Impulse 2 that caused the problem, so phasing that power back down to more sensible levels could well be the answer. In short, it was the desire to have the most powerful legal crank unit that was unwise without a complete redesign.
.
 
Apr 28, 2015
388
36
43
#19
The troublesome gear was perfectly ok in the Impulse 1
.
I thought some of the gears had been changed to plastic to make the motor quieter (while increasing its torque at the same time)?

I guess if their motor parts can't handle the extra torque, then the design can be considered flawed. It also seems that some sensors are failing in the motor (and the Evo version is now "more robust" and "with extra sensors").
 
Oct 25, 2006
40,227
186
113
#20
I thought some of the gears had been changed to plastic to make the motor quieter.
As far as I know it always had the nylon intermediate gear wheel.

Originally created by the Daum company before Kalkhoff got the rights, it had software programming that tempered the power peaks. Basically on setting off or first applying any higher power stage, the full power only lasted a few seconds and then slightly reduced.

The customers didn't like that so Kalkhof altered it both in the production and after market via the agents resetting it. From then the full power was available all the time in the Impulse 1, but that increase didn't cause any problems.

Initially the Impulse 2 didn't seem to cause any problems, here at least, but its software was changed a few times, both in terms of power level and in varying the power during gear changes to smooth those. The nylon gear shredding seemed to coincide with that period of software changes.

Of course I've no way of knowing if they ever had any batches of faulty components, but the indications are that it was the continuous increases in power output and torque that produced the problem. Not surprising, Heinzmann for many years had only supplied a nylon gear in their road legal 200 watt motor, all the higher rated ones with steel gears.
.
 

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