Creeking Crank

[RichardTuxford]

I have a 2008/9 Kalkoff Agattu (with trike conversion) and have recently noticed a 'creeking' type sound from the crank area which is particularly noticeable when pressure is put through the pedals obviously more noticeable when working them quite hard going uphill?

I'm sure (hopefully!?) this is nothing particularly sinister and can be rectified quite easily and which may not be a Kalkoff problem but generic to e-bikes.

Hopefully someone will be able to signpost me to an easy rectification?

Look forward to hearing from you all

Richard

ps I'm running the Panasonic motor

 

[flecc]

It could be a crank arm slightly loose on the square taper of the pedalshaft, but on these it's most likely to be slackness in the three large bolts that secure the unit to the frame. The frame is painted and over time the strain of applied pedal force works the faces a bit slack.

You'll need to remove some cowlings to get at the three bolts. Two of them are just forward of the pedalshaft, the remaining one at the top roughly above the motor sprocket shaft. They need to be very tight.
.

 

[RichardTuxford]

Flecc - that's really helpful, thank you. However, I'm not very technical and think I think I know the areas you are referring to but wonder if you could explain the first part a little for me? By the unit, are you referring to the motor?
Apologies for being a little thick!!

 

[flecc]

Yes indeed Richard, I meant the motor unit. Here's a photo of an upside down frame showing the three bolt holes for the motor unit arrowed. Your frame shape is different but the hole relationship is the same:

And here it is with the motor unit lined up:

 

[Martin@e-bikeshop]

It could be a crank arm slightly loose on the square taper of the pedalshaft, but on these it's most likely to be slackness in the three large bolts that secure the unit to the frame. The frame is painted and over time the strain of applied pedal force works the faces a bit slack.

You'll need to remove some cowlings to get at the three bolts. Two of them are just forward of the pedalshaft, the remaining one at the top roughly above the motor sprocket shaft. They need to be very tight.
.

Second this Flecc. 99% of time it will be the 3 motor bolts.

Just to expand, you should remove and apply a light smear of grease to both sides where the motor mounts and then torque the bolts to a recommended (ridiculous) 40Nm.

I personally would go 30Nm just because the bolts you have are old and may have stretched and we don't want to snap them. If it creaks, you can always go a little tighter as its fairly easy to access them.

Regards
Martin

 

[flecc]

Agreed Martin, that 40 Nm is frightening, and some have sheared the bolts. The bolt quality seems to have been variable too, with a few cases of the threads stripping. That's why I duck out by just saying the bolts need to very tight!

 

[Martin@e-bikeshop]

Yes this is very tight! This is what it states in my dealer book. Maybe on decent brand new bolts, but still, very much too tight!

"Very tight" is a good way forward

Martin