What’s the Crack ?

Aerialmark

New Member
Oct 8, 2021
10
2
Uk
Hi, have a Cube Stereo 140 with about 2.5 thousand miles on it and I’ve recently started to get a loud cracking sound coming from around the crank area ( where they connect to the motor) when I put a lot of pressure on the pedals. Is this a relatively easy bearing fix or is it motor out and refurbishment ?
A week on Monday I’m getting the train with my bike up to Glasgow and riding home to Burnley on the tracks trails and backroads so could do with getting it sorted before I go.
 

RustyIron

E*POWAH Elite World Champion
Subscriber
Jun 5, 2021
1,744
2,690
La Habra, California
Seatpost, bottom bracket, pivots, headset, cranks, pedals... those are just a few of the places you can start looking. A thin film of grease prior to assembly can mitigate most noises.
 
Last edited:

MrPeaski

Active member
Sep 21, 2020
259
210
South Wales
Just to add to what @RustyIron has mentioned, motor holding bolts too.
there's 2 sets, one set that hold the mounting plates to the motor, and 1 set that holds the mounting plates into the frame.
For these you'll need Torx+ bits and drop the motor out to tighten up the mount plate bolts.

The torque for these are 6Nm for the small bolts that hold the plates to the motor and 11Nm for the larger bolts that hold the motor in the frame
 

Daboss

Member
Jan 17, 2021
44
31
Melbourne
Had the same issue, wasn't the motor bolts as I pulled these out and refitted etc and torqued, ended up being the bottom shock pivot bolt was dry asf, so I replaced it greased it etc, and it's been mint for 2000ks thus far. I'd suggest pulling that out and regressed and re check.
 

Daboss

Member
Jan 17, 2021
44
31
Melbourne
Just to add to what @RustyIron has mentioned, motor holding bolts too.
there's 2 sets, one set that hold the mounting plates to the motor, and 1 set that holds the mounting plates into the frame.
For these you'll need Torx+ bits and drop the motor out to tighten up the mount plate bolts.

The torque for these are 6Nm for the small bolts that hold the plates to the motor and 11Nm for the larger bolts that hold the motor in the frame
Just to confirm for the Bosch units on the cube frame the torx40 bolts are listed as 20nm as per the doc I received from the Bosch rep.
 

MrPeaski

Active member
Sep 21, 2020
259
210
South Wales
Not wishing to start a war about torque settings, but 20Nm is ok for an aluminium frame, but for carbon they are as I mentioned.
I erred on the side of caution, just in case the OP's frame is carbon.

There is a thread on here that shows what happens when bolts are over torqued on carbon frames
Here....

See post #71 for the outcome and the proper bolt torques.

HTH
 

Daboss

Member
Jan 17, 2021
44
31
Melbourne
Not wishing to start a war about torque settings, but 20Nm is ok for an aluminium frame, but for carbon they are as I mentioned.
I erred on the side of caution, just in case the OP's frame is carbon.

There is a thread on here that shows what happens when bolts are over torqued on carbon frames
Here....

See post #71 for the outcome and the proper bolt torques.

HTH
Totally agree its a guide and with everything err on the side caution when doing things like this , but this bloke went 30Nm.
Just passing on the info I go from the bosch. each to their own.
 

Daboss

Member
Jan 17, 2021
44
31
Melbourne
Which it is.

From the thread

" I later asked the shop to clarify what the correct torque was for those large motor mount bolts. I was told 11nm for the large bolts that go through the frame to the motor brackets and then 6nm for the smaller bolts that hold the brackets to the motor casing itself. It would be nice if these figures were just listed online somewhere... "

Try it see how you go, but Id still go the bottom shock pivot bolt regressed. re-torque to 8nm from memory.
 

MB1

Member
Dec 28, 2019
38
31
Cumbria
My money is on the motor mounting plate bolts, I’ve had the very same issue, weeks in at wheelbase in Staverly, £100 bill to replace the (£8) bracket and trap all the main motor cables damaging them in the process. Ended up re-doing all the work myself removing the thin sticky gaskets from the bracket and replacing it with copper slip… all good.
 

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