Hi,

 

First of all I would like to say hello to all the forum members with whom I've communicated in the past and who have given very helpful advice. I'm again having some issues with my pro connect. So any help or advice would be greatly appreciated.

 

My kalkhoff pro connect 9 G (2010) has started to emit a small intermittent squeaking noise recently. The squeaking only appears when the power is switched on and is present on all levels of assistance. My first thought was that maybe the bolts that attach the motor to the frame are becoming loose as it has been found to be the main reason that causes such a noise. However, on closer inspection, bolts appear to be firmly tightened. What's more, the squeaking resembles more to the noise that a pedal that needs lubrication would emit. And the noise is very regular - it is only emitted every 3-4 pedal revolutions, and only when the power is switched on. Moreover, it does not depend on the terrain - it is present on the smooth as well as on rocky surface (excluding thus the hypotheses of squeaking resulting from the motor movement).

 

Thus, the only thing I could think of is some inner bearings inside the motor that would cause such a noise and that need lubrication. However, I have no idea whether it is possible to lubricate them and how to do it. My bike is still under warranty until next September. So I should probably not fiddle with the motor. Could you give me some advice what you would recommend me to do (ignore it, try to repair myself or bring the bike back to the dealer although he might dismiss this squeaking as it does not affect the transmission or power)

 

Concerning the usage, I've done around 4000-5000 miles with my pro connect. However, my usage is quite intense (35 miles a day) and I use higher power modes a lot because of the very hilly terrain. Moreover, since this summer I've shifted to 11 teeth motor sprocket (that solved the roughness and rattling issues) that has noticeably increased my average speed (thus I almost do not use "eco" mode any more)

Edited November 22, 201114 yr by vaasa

Hello "vaasa",

sadly I'm a lesser engineer than most on this forum. However, your mentioning that the noise happens at so slow an interval has me thinking that maybe the chain is the squeaker?

I think it must be external to the unit. A "dry" inner nylon gearwheel section would not correspond to this happening once each three to four pedal turns frequency, it would squeak between three and four times per one pedal revolution, depending on whether you had a 37 tooth or 41 tooth chainwheel with the 11 tooth motor sprocket. The only other moving part inside is the magnetic torque sensor and that would give one squeak per pedal revolution.

 

It must in some way be due to the transmission area. I'd check first the security of the chain idler arm mounting, then any detachable chain link fitted to see if that is rubbing as it passes through the idler arm gap (common problem). As for the motor mounting bolts, it's more pedal effort that causes noise from that source, rather than rough roads. Does the noise correspond to when you are putting in lots of effort, or is it independent of effort?

Hey Hihihi,

 

I was thinking the same thing, i.e. that the chain might cause it, e.g. a bad link. That would explain the squeaking in every 3-4 revolution as the chain goes full cycle. I've also recently changed the chain (as well as the rear cogs; and also turned the motor sprocket around); so maybe the connection link is causing the issue. However, it is only squeaking when the motor is switched on. That would work against the chain being the cause. Anyway, I'll lube and check the chain again this weekend to see if it will solve the issue

Now you've mentioned the connection link, that's very likely the cause, see my post above, just before yours.

Thanx Flecc for a comprehensive explanation how the system works!

 

Considering your points, I think it should be then either transmission or the the loose bolt issue. I tend to think it is more transmission related because the noise is regular like clockwork - every 3-4 pedal revolution. I'll try to check all the things you said and see if it will solve the problem. Maybe one link is a bit stiff. However, as it only becomes evident when the motor is switched on, I would think that the motor sprocket is somehow involved in the squeaking. Still, nothing is felt in the pedals and the transmission is smooth (not comparable with the roughness or rattling problem discussed extensively in the forum.)

 

The noise does not seem depend much on the power applied. Although I do get the impression that the squeaking is more pronounced uphill. But this can be due to the fact that I'm going slower and the wind blowing through my ears also slows down letting me to hear it better (it is not audible in traffic for example)

 

 

Concerning the motor bolts, is a normal screw driver enough to loosen or tighten them? Having seen the bolts, I tend to think that you would need much more massive and consequential tools to do it. Otherwise I might just damage the bolts (screw drive would slip) as the force applied would not be enough to tighten them. The bolts seem to be not easily accessible on new pro connects either; therefore sufficient torque and pressure would be difficult to apply.

Edited November 22, 201114 yr by vaasa

The motor bolts do need to be very tight so a spanner on the nuts is necessary, and as you say, the cowlings would need to be removed to some extent to do that. I'm not familiar with the cowls on the latest units though.

 

The transmission is favourite for this squeak though, and spring clip connector links are often too tight a fit between the side plates of the idler arm(s). If you have that type of connector link, I'd check how that passes through the arms first.

I'm using special Shimano chain rivets to connect the chain. But as the the chain has to be joined in two places (normal chain is not long enough) there still remains a possibility of rough link/connection. Though, the fact that the squeaking only appears when pedaling with the assistance still seems a bit strange.

i have a pro connect that also has this squeaking,it is not the chain,jockey wheels, gears or anything transmission related because the noise only happens when electric assistance is used so it must be motor related,the motor is new so wear is not the problem,if anyone has any solutions i would be keen to hear them because the squeaking is quite loud and off-putting and takes away the pleasure of riding the bike.

The main source of this squeaking internally I can see is the nylon helical gearwheel, running dry against the helix on the motor shaft. However, that rotates 3 to 4 times per chainwheel revolution which doesn't fit with a squeak that's at less frequent but regular intervals. The two photos below illustrate this, the first showing gearwheel and motor shaft drive, the second showing the motor shaft helix:

 

http://myweb.tiscali.co.uk/flecc/images/IMG_2619b.jpg http://myweb.tiscali.co.uk/flecc/images/IMG_2612b.jpg

 

Those and the bearings are all that move in the unit apart from the pedelec sensor shaft which turns at pedalling rate of course. However, the latter is ruled out by the squeak being power related.

 

The motor mounted on the crankcase sidewall is the one long used on these units and the only noise that has ever cropped up from there is a rumbling/grinding on the rare occasions when a motor shaft outer end bearing has failed due to the the lateral thrust loading.

 

The only suggestion I can make for units out of warranty is opening them up and regreasing the drive gear, for that my webpage on this link may be useful.

 

The stripdown procedure illustrated for the older unit largely applies to the newer one, so this webpage also from my Panasonic support site can help.

I haven't yet had the time to check my transmission. However there is one curious fact with this squeaking noise that is worth mentioning. The noise does not start right away. It only starts after 2-3 miles. It's as if it is related to the warming of the motor because when bike is left idle for only a small amount of time (and especially inside where it is warmer), then the squeaking does not disappear. It only disappears for the first couple of miles after the bike is left idle for a longer time.

 

I still somehow hope this noise is transmission related but I have some doubts because I've changed chains many times without any problem. And this new chain worked fine for the first 200 miles. And from my biking experience, I've never had such a squeaking noise coming from transmission.

Edited November 23, 201114 yr by vaasa

it can`t be a problem with lack of grease because mine is a nearly new motor and as vaasa describes the squeak is not there until 2 or so miles have been covered when the motor starts to warm.

Inside the unit there is a plastic shield to keep grease clear of the electronics. I suppose that might conceivably be distorting enough with warmth to start rubbing on the side of the nylon gearwheel. The rather indistinct photo below shows that shield:

 

http://myweb.tiscali.co.uk/flecc/images/IMG_2636b.jpg

 

However, that doesn't seem a likely cause. As said, I've shown all the moving parts associated with the application of motor power, and squeaking is unlikely between adequately greased parts.

This one is a puzzler. If it only occurs every 2 turns of the pedals, it has to be something rotating slower than even the crank cog, which only leaves the chain!

Does it instantly stop if you switch off? (ie must be related somehow to the electric assistance)

Are you absolutely sure it is the drive system, could it be the saddle etc?

The squeaking stops as soon as the power is off so it must be related to electrical assistance,no matter how hard i pedal it won`t make the loud squeaking noises until the power is on,all the components on the bike that can make any noises have either been renewed or lubed and everything is tightened up,the bike is silent until you turn the assist on.

Nemesis could not have said it better. I have exactly the same issue. Two of us having this very particular squeak (appears only when motor is turned on, disappears when turned off, does not start before 2-3 miles before motor is warmed, emitted every 3-4 pedal revolutions) seems to corroborate quite strongly common origin to the problem

Edited November 24, 201114 yr by vaasa

Is it more obvious or louder when the bike is switched to high power mode such as when climbing a hill?

Have you tried removing the chain and running the drive unloaded for a equivalent time corresponding to 3 miles?

The noise is almost certainly something to do with the chain because of the frequency. Many chains have uneven freeplay in the links so that tension varies when the chain goes round. I suspect that the chain is on the border of making the squeak on its own, and when the motor gives power, it changes the tension enough to push it over the squeaking boarder. Maybe under these conditions it's just able to touch something or the tensioners oscillate a bit more while it goes round. In case you haven't already done it, put some oil on the tensioner and rear derailleur if you have them - and lots on the chain. I'm sure it's nothing to worry about.

the chain is new and well oiled,i changed it to see if this was the source of the noise and there was no difference.

One thing that I am not clear about is the frequency of this squeak.

Does it occur regulaly every 2 turns of the pedals and when the right hand pedal is in the same position?

Does its frequency in relation to the turns of the pedal crank change when you change gear?

Because it takes 2-3 miles before it becomes apparent, it suggests that something is expanding through heat.

Does the motor get hot?

Are you absolutelty sure where the squeak comes from? I am thinking of things like ensuring the wheel nuts are tight etc.

Have you been able to check the tightness of the motor bolts? Remember that if the motor heats up, bolts that are tight when cold can become slightly looser.

but have tried running the motor without the chain?

Thank you for all your suggestions. I'll check, clean and oil the transmission of my bike this week end to see if that helps. I'll let you know if anything changes. I think I can't run the motor without the chain though, because I do not have a throttle (I have a C pedelec, the motor of which only runs when the pedals are pushed with some force) Thus, I do not see how I can activate the motor without the chain.

 

To respond to some of your questions: It happens every 3-4 chain-wheel turn and the pedals do not seem to be in the same position each time; I'm not sure where it comes from, although the regularity of the noise (like clockwork - every 3-4 turns) seems not to support the loose bolts of the motor as a likely cause. I share the opinions of flecc, d8veh etc; that the transmission seems to be the most likely cause because of the regularity of the noise. However, the oiling and the change of chain did not seem to make the noise emitted by the nemesis' pro connect to go away. I'll see how it goes for me...

The best chance that you will have of locating this noise is by investigating the frequency and from this eliminating components. Can you answer the following questions?

 

1) If you ride in a fixed gear, any will do, does the frequency of the noise increase and decrease with road speed (ie varying the road speed through pedal cadence)?

 

2) If you ride at a fixed road speed, does the frequency of the noise increase and decrease with changing gear ratio (ie varying cadence via the gears)?

 

3) if you ride at a fixed pedal cadence (The best you can), does the noise frequency increase and decrease with changing gear ratio (ie varying road speed via the gears)

 

The answer to these questions should reveal if the noise is coming from the motor or transmission. Once you know the answer to this question, further investigation can be carried out to narrow down the likely source.

I had a similar problem for a short while - I found that somehow one of the rear axle nuts had come loose, giving the rear wheel a small amount of movement.

 

I say came loose - I don't want to admit that I may have neglected to tighten it properly following a thorough clean-up.