Noise problem with Kalkhoff Pro Connect series - a serial & systematic issue?

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vaasa

Pedelecer
Nov 14, 2010
35
0
Hi,

I realize that is my first post. So for short introduction, I bought my Proconnect C 9G (2010 version with derailleur) this summer from a major dealer near Paris. I've been very pleased with my bike so far. It really helps me to climb the hills on my commute from Paris to Jouy en Josas (near Versailles)

However, from the very beginning there was always a clicking (or even somewhat rattling) regular noise once I shifted to medium or higher power mode and climbed a hill. First, I did not pay too much attention to this as in economic mode (most of my ride) it is almost nonexistent and it does not appear at all when cycling without power. Moreover, this being my first e-bike, I was thinking it might be related somehow to the motor's assistance (however, I later realized that the motor only makes a very quiet wheezing sound)

Long story short, I took it back to my dealer who has represented Kalkhoff for years and seems to be very professional. After having checked my bike, he found nothing wrong. He conceded that this clicking rattling noise apparently exists when switching to higher power mode but this noise is also present to the other kalkhoff bikes they sell. So they found it normal and told me to come back if the problem exacerbates. Actually what they say is true to the extent that while my bike was in reparation, they gave me a new one with Alfine hub gear (instead of derailleur) and it had the same clicking-rattling noise when in higher power modes and climbing. However, another dealer (not the one from whom I bought the bike) told me, after having examined the bike, that this is not normal.

However, I could not let it go as it really disturbed me and you could feel it well in pedals when cycling - this kind of reduces my cycling pleasure. What was especially puzzling is that it got worse after degreasing and chain lubricating, which should normally reduce all sorts of transmission issues. I also read all the post from this forum and others about the noise issue and found that many others have had a similar issue but the solution was not really found or the bike was just replaced.

Therefore, I decided to investigate the problem myself after having read instructions in the flecc's web page dedicated to panasonic crank motor. I checked for all possible issues described on the site - chain, sprockets wear and tear etc. (although I have used the bike only for 1000 miles, so the wear should not really be an issue) but everything seemed normal. But as it is impossible to simulate the real conditions in my garage (the assistance will not kick in), I took off the chain cover (in order to see and hear better) and went to try my bike on a hill. And I made a somewhat surprising discovery, I haven't read about on this site or any other (unfortunately I can only read French and English and not German). This rattling and clicking noise is coming from the chain not properly engaging and jumping on the idler arm's sprocket in higher power modes.

Hence, after coming off from the motor sprocket, the chain does not engage well on idler arm's sprocket and it only happens on the motor sprocket side (not on the derailleur side). So it kind of rules out the that it is caused by the high angles chain forms with derailleur (indeed, problem is present in medium, low as well as high gears, and, as I mentioned before, the Pro Connect with Alfine Hub had the same issue). The chain tension should not cause the problem as well (as I have a derailleur), I think (though I'm far from being an expert). What's more, the chain seems to be perfectly aligned on the motor and idler arm's sprocket. I also checked the distance between the centres of the sprockets(as indicated on flecc's site) and it is well between 60-65 mm as required. Anyway, with newer models you have a metal structure build around idler arm and motor sprocket so that once you tighten the idler arm it slips into a slot and it does nor really move, except a couple of mm (just to be sure, I tried both positions, but the clicking rattling problem remained). Otherwise, both the idler arm's sprocket and the motor sprocket (original, nine teeth version) are well fixated (no side movement) and there is no hindrance to their free movement.

After having done all that I'm short of ideas what to do and how to fix this issue. It seems to me that it is clearly an idler arm's sprocket issue as this sprocket is quite particular. It has 11 blunt teeth, which are very long. Compared to a normal derailleur sprocket, these teeth are twice as long and very blunt. Therefore, it seems to me that after coming off the motor sprocket in higher power modes, this kind of built is not enough to safely engage the chain (it intermittently gets on top of the teeth and jumps back again to the correct engaging position - thus causing the noise). I checked in the internet and found that normally an idler arm's sprocket (in any industry) has either sharp, well engaging teeth (like those of the motor sprocket) or it does not have any teeth at all (like the one cyclone uses for it's crank motor - a plastic tube) so that the chain can just smoothly go over it without any issue. However, before trying to find such a sprocket (which is quite tough because the specifications are not the same - i.e. I also tried to unsuccessfully fit a normal 11 teeth derailleur sprocket, which is too narrow) I wanted to ask for your advice what to do. As I'm just a novice as far as electric bikes go, it might be that I'm completely off with my reasoning. However, as of right now it really seems to be a serial issue for me as it is the same for Alfine hub as well as for derailleur. Moreover, most people, I think, let it go as you barely hear it in traffic (although you can certainly feel it when pedaling in higher assistance modes) and it does not affect the power transmission (motor sprocket works ok) - although it certainly might use the chain out a lot quicker. The proof to that is my dealer (a former semi-professional cyclist) who does not think the noise is a big deal (although he hasn't investigated the cause as I did). I've read a lot of very similar descriptions of this noise problem with new Kalkhoff bikes but no one seems to find a solution (or at least does not post about it) and often the bike is just replaced (with the new bike probably having exactly the same problem but it is too much of a hassle to make a new inquiry)

Finally, I think I've also found the explanation why the problem exacerbates after degreasing and lubricating. The chain becomes much more slippery (I you use a wet lube in winter) and is engaging even worse the blunt and long teeth of the idler arm's sprocket. That is why the problem is less noticeable with a brand new bike with a waxed chain (less slippery). And one more thing (I know, I know, my post is already very long), I was thinking that maybe a 9 teeth motor sprocket somewhat causes the problem, as I've read from somewhere that it should at least be 11 teeth (but due to due legal restrictions, 9 teeth version was fitted) in order all the transmission parts to work smoothly. However, as my motor sprocket works fine, I don't know if it is really an issue. So please tell me what you think and if you have experienced similar problems. I really hope it is not a serial issue. Otherwise, I would have to write to Derby bike directly because my dealer can hardly help with a systematic issue that seems minor to him. I don't want to lose my bike for months as well.

Please forgive me for the length of my post and also for some spelling & language errors :)

Vaasa,
Paris
 

flecc

Member
Oct 25, 2006
52,803
30,375
Hello Vaasa, welcome to the forum, and I'm sorry to hear of this irritating problem.

If there is a weakness in the principle of the Pansonic unit system's relationship to the bicycle side, it is in this motor sprocket to chain area. Firstly, though not mentioned in my site at present, the 60 to 65 mm really only relates to the models with hub gears and no rear tensioner. It ensures that the idler arm is not used as a substitute for proper chain adjustment using the rear spindle frame slot facility.

I think that in your case the spring tensions in the rear mechanism pivots which pull it back against the front tension may be inadequate.

The rear mechanisms do vary in this respect, which on normal bikes doesn't matter, but on the Panasonic system the balance of tensions can be important.

First the "B" screw adjustment should be tried, this is nominally for the spacing of the rear mechanism idlers to the cassette, but it also affects tension slightly. Here's a video tutorial for you.

This only has a small chance of success, the next step is increasing the actual internal rotation spring tensions. This is technically more difficult and you may prefer a skilled cycle technician to do it, but if you wish to try yourself, here is the Park Tools Tutorial on how to do it.

I hope this proves to be the answer for you, but do please let us know if it is successful.
.
 

WALKERMAN

Esteemed Pedelecer
May 23, 2008
269
0
A very interesting post Vassa.

I have had rattling from that area of my two and a half year old hub drive PC. I changed all the sprockets and the chain. The motor sprocket and the large sprocket were well worn having done about 5500 miles. This was only slightly quieter with the new parts and recently I have begun to suspect the left hand pedal as I feel the vibration more on that side. I don't know what else to check!

With regard to contacting Derby Cycles in Germany I can only wish you good luck because I wrote to them several months ago about the suspect early 24 spoke wheels, fitted on my 2008 bike, and they didn't even have the courtesy to reply. Needless to say they won't be getting another order from me.
 

vaasa

Pedelecer
Nov 14, 2010
35
0
Thank you very much flecc and walkerman for your welcome and you replies. I'll try your recommendations, flecc, and wil tell you how it goes. I'll be away for 2 weeks and reading through all these technical instructions wil take some time as well :). So probably won't post too soon. But thank you again flecc for indicating a solution for my issue.
 

vaasa

Pedelecer
Nov 14, 2010
35
0
Hi Flecc, Scott and others who kindly answered to my plight,

After a long hassle and after having my bike taken back to Germany for 2 months only to have the problem reappear again in no time, I've finally found a foolproof solution to the issue by myself with some common sense. I describe the solution in detail in another thread of this forum as a response to the people who complain about exactly the same issue with their newly acquired Kalkhoffs. I think it might interest all the owners of the electric bikes fitted with the Panasonic crank motor (and particularly with a 9T motor sprocket) as, according to my observations and also the number of people complaining about the noise, slipping and rattling issue, it is a serial weakness of transmission of such systems. It can be easily fixed, though, by fitting a bigger motor sprocket (i.e. a 11T) and/or a chain-wheel (i.e. a 41T in order to keep the same assisted cadence) and by adjusting accordingly the rear cog(s) to remain in legality. I wander why Derby cycle engineers and/or dealers do not tell us this simple solution that even a complete novice like me can come up with by using some common sense. Having worked in business myself, it finally comes down to the fact that everything is geared to make profit for the shareholders (Derby went public this year). However, often consumer will suffer from poor quality product/after service. I really hoped to have a better experience with otherwise reputed German engineering. I will strongly consider my alternatives before buying my next e-bike.

Best regards,

Vaasa
 

vaasa

Pedelecer
Nov 14, 2010
35
0
Hi Scott,

If you've read my posts, you know that I've bough my bike not from UK but from France where I live (in Paris, to me more precise). But this is not the issue. The problem I'm talking about appears to be recurrent as witnessed by another post of complaints of many people with the same issue, to which I responded with a more detailed response describing the solution, and to which I provided also the link in my above post. Here it goes again, if you missed the link. I could provide you many more links with people having the same transmission issue (although some of them are in French) In my detailed post, I'm not saying that the dealers in UK, and especially 50 cycles, have the same issue. As to me, you have been more than helpful and forthcoming, even though I bought my bike from France. What I'm saying is that as evidenced by the number of people complaining about exactly the same issue (look at the other thread where you responded yourself) with their new, or relatively new Kalkhoffs, there might be a serial weakness to the system. If you read my detailed response carefully, everything points to that direction. That you do not get many returns with this issue might be explained by the fact that many people make-do with the noise and chain slipping as described in this other thread. Moreover, the hub systems (majority of your sales) will not have this problem if the chain tensioner is installed correctly and is not of dubious quality (sturmey archer or whatever instead of Shimano). Again, I invite you to read the other thread to get a full apprehension of the issue.

Best,

Vaasa
 

Tonto55

Finding my (electric) wheels
May 19, 2014
12
0
67
Hello Vassa,

I know it's over three years since your post about noise from Panasonic motor.

I am experiencing very similar noises on my bike. I can only describe as a racheting clicking noise and only when the system comes under load like cycling up hill or changing up a gear.

Have you any suggestions as to what I can do to stop this irritating noise?

Regards

Tonyo55
 

Roger R

Pedelecer
Jul 6, 2015
50
30
69
Hi All - I bought my Pro Connect 10 just over a week ago and have exactly the same problem. I have recorded the noise and contacted the dealer (50 Cycles) and am awaiting a response. Based on the noise this is going to cause damage over time and I am far from happy. Seemed such a good quality bike until this issue occurred. As stated in other posts only occurs in power mode going up hills.
 

bilabonic

Esteemed Pedelecer
Feb 20, 2013
294
6
Hi All - I bought my Pro Connect 10 just over a week ago and have exactly the same problem. I have recorded the noise and contacted the dealer (50 Cycles) and am awaiting a response. Based on the noise this is going to cause damage over time and I am far from happy. Seemed such a good quality bike until this issue occurred. As stated in other posts only occurs in power mode going up hills.
Can you post a soundbite of the noise as i also have similar.
 

Roger R

Pedelecer
Jul 6, 2015
50
30
69
Hi - don't seem to be able to upload the audio file. Give me your email address and I can send it?

Roger
 

Roger R

Pedelecer
Jul 6, 2015
50
30
69
Just had a call from 50Cycles. Suggested I give it another two weeks to see if the motor 'beds in' and then to get back to them. I agreed and we will see! Also said that if the problem does not resolve they will take it in to look at it.
 

Roger R

Pedelecer
Jul 6, 2015
50
30
69
I took it out today and went up the same hills but with lower gears (mine has 10 gears) - mostly 2 or 3. Didn't get the problem at. I was maybe putting too much strain on the system before. Don't really know.
 

dinger19

Pedelecer
Jun 30, 2014
234
178
65
Kent
You don't hear a bad thing about Kalkhoffs and now potentially 2 major faults in as many weeks.
 

Roger R

Pedelecer
Jul 6, 2015
50
30
69
Update on the noise issue. Now done nearly 400 miles and problem not reoccurred. Have to say I am overall very pleased with bike. The last trip I covered 60 miles and had only used one third of the battery. I was on eco all the time and peddling hard but still pretty impressive. Also had a call from 50 cycles asking about the noise problem so can't fault their support. So onwards and upwards!

{from Admin: please create new topics now due to the age of this thread)
 
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