2021 Cube 140 Action Team Bosch motor mount torque setting

[Gareth]

Wondering if anybody can help me with this.

I’ll get the important bit in first.

Does anybody have an official torque setting for mounting the Bosch motor on a 2021 Carbon Cube frame.

I know that Bosch quote 20Nm, but is that for an aluminium frame? Is the figure lower for Carbon?

The second question is – does anybody know a top notch carbon repair expert. What I’m looking at is repairing the motor mounts – filling – redrilling and fitting new inserts. Yes – really!

So now for the tale of woe if you are interested.

So bought my Cube Hybrid 140 Action Team in 2021.

The motor failed in November 2023 after 3600 miles. Unfortunately, I’d parted ways with the shop I bought it from. I had just been told by the ‘reputable’ shop I was subsequently dealing with that my motor was in good health (really, as I now know, it was showing all the usual signs of failing – bit of play in the bearing, stickly clutch and the odd error message – it was time to overhaul it but I was told all was well). I wasn’t that convinced but didn’t know where else to seek advice, and knowing I wouldn’t be able to get warranty service I did enquire as to what the torque setting was for the Bosch motor. I was told 40Nm. I asked if they were sure, as my torque wrench was suggesting just over 20Nm as it was. I made a note of 40Nm as my man was adamant it was 40Nm.

So anyway September 2023 I paid a grand to get all the issues with the bike fixed (pivots, suspension, new rear hub etc). They also checked the motor was torqued in OK.

200 miles later the motor dies – dead as a dodo.

I take the motor out and send it for independent repair. Motor is dead – unrepairable as it has so much water in it, it drowned the circuit board.

So I bought a reconditioned motor.

This is where things get really bad. I remember the 40Nm figure, and I check my notes as I wrote it down. I fit the reconditioned motor and start nipping it up. I get to just over 30Nm and decide that 40Nm is clearly bollocks, it doesn’t feel right at all. I back it off and settle on 25Nm.

I later find the 20Nm figure.

Anyway, refurb motor fails a couple of hundred miles later and off it goes for warranty claim. And yup that’s when I discover the damage I’ve done to my frame.

Two of the mounts look OK. Three I had to tidy up significantly with a file. One insert had come off altogether – sanded down the carbon fibre and glued it back in with VM100 glue from Easy Composites (very helpful company)

Motor is back in and torqued to 13Nm. Bike is ready to go – fingers crossed. I get the feeling 20Nm is too much.

So back to the question – does anybody know the official torque figure?

Second yeah the second question is – does anybody know a carbon repair specialist who could repair my motor mounts. It might last as it is but I just don’t know. I can do simple carbon repairs, and I can see it is repairable but basically it is the precision aspect of it.

Thanks!

 

[rotary]

Wondering if anybody can help me with this.

I’ll get the important bit in first.

Does anybody have an official torque setting for mounting the Bosch motor on a 2021 Carbon Cube frame.

I know that Bosch quote 20Nm, but is that for an aluminium frame? Is the figure lower for Carbon?

The second question is – does anybody know a top notch carbon repair expert. What I’m looking at is repairing the motor mounts – filling – redrilling and fitting new inserts. Yes – really!

So now for the tale of woe if you are interested.

So bought my Cube Hybrid 140 Action Team in 2021.

The motor failed in November 2023 after 3600 miles. Unfortunately, I’d parted ways with the shop I bought it from. I had just been told by the ‘reputable’ shop I was subsequently dealing with that my motor was in good health (really, as I now know, it was showing all the usual signs of failing – bit of play in the bearing, stickly clutch and the odd error message – it was time to overhaul it but I was told all was well). I wasn’t that convinced but didn’t know where else to seek advice, and knowing I wouldn’t be able to get warranty service I did enquire as to what the torque setting was for the Bosch motor. I was told 40Nm. I asked if they were sure, as my torque wrench was suggesting just over 20Nm as it was. I made a note of 40Nm as my man was adamant it was 40Nm.

So anyway September 2023 I paid a grand to get all the issues with the bike fixed (pivots, suspension, new rear hub etc). They also checked the motor was torqued in OK.

200 miles later the motor dies – dead as a dodo.

I take the motor out and send it for independent repair. Motor is dead – unrepairable as it has so much water in it, it drowned the circuit board.

So I bought a reconditioned motor.

This is where things get really bad. I remember the 40Nm figure, and I check my notes as I wrote it down. I fit the reconditioned motor and start nipping it up. I get to just over 30Nm and decide that 40Nm is clearly bollocks, it doesn’t feel right at all. I back it off and settle on 25Nm.

I later find the 20Nm figure.

Anyway, refurb motor fails a couple of hundred miles later and off it goes for warranty claim. And yup that’s when I discover the damage I’ve done to my frame.

Two of the mounts look OK. Three I had to tidy up significantly with a file. One insert had come off altogether – sanded down the carbon fibre and glued it back in with VM100 glue from Easy Composites (very helpful company)

Motor is back in and torqued to 13Nm. Bike is ready to go – fingers crossed. I get the feeling 20Nm is too much.

So back to the question – does anybody know the official torque figure?

Second yeah the second question is – does anybody know a carbon repair specialist who could repair my motor mounts. It might last as it is but I just don’t know. I can do simple carbon repairs, and I can see it is repairable but basically it is the precision aspect of it.

Thanks!

This has been discussed on this forum before but i cant find the thread. I have the following torque figures which i wrote down at the time of reading

Motor mounting bolts for aluminium frame = 20Nm
Motor mounting bolts for carbon frame = 11Nm
smaller bolts which attach brackets to motor = 6Nm

I've not got around to doing a break and re-make to measure the current torque on my bike but will at some point.

This is what pi**es me off about big bike companies like cube. Simple torque data should be readily available.

 

[Cocodrilo]

Mismo cuadro un año mas viejo, con lo cual es valido.

Motor mount torque settings

Anyone know the torque figures for motor mounts on a 2022 cube stereo?

www.emtbforums.com

 

[Gareth]

Thanks Rotary and Cocodrilo, looks like I’m not the first to end up in a mess with this.

Would be nice to see that 11nM on a Cube document. But that figure does make sense, as you wouldn’t expect catastrophic failure from a 50% over torque. (ie from Bosch manual figure of 20Nm)

I suspect a lot of these bikes will be getting over torqued. Also looking at older photos I have of when I first removed the motor myself there appears to be signs of damage from when the motor was removed and refitted by the original dealer (I had the charging socket replaced under warranty)

It is really frustrating. Why they just don’t mark the torque figure on the motor mounts like they do with everything else is beyond me.

I am obviously also kicking myself as to why I thought for one second that the 40Nm figure that the bike shop gave me was in any way reasonable. But hey too late now.

I took the bike out last night for a short 12 mile run along some local hydro and estate roads, and it seems to be fine. But it is now compromised. It is now a case of fingers crossed and see how long it lasts.

Will see is I can get some snaps up when I get a chance.

Thank-you!

 

[Gareth]

 

[Gareth]

You can see the insert has distorted and the paint around it has cracked, but hopefully this one is still firmly bonded to the carbon.

The rear ones look OK.

I'm not sure but I think there should be carbon before the insert from the outside of the frame - it looks to me if I have crushed it. Would need to see a good frame to know.

 

[Gareth]

I bought some carbon compatible adhesive - this stuff is what is typically used for bonding inserts to Carbon. It is VM100 glue from Easy composites - Materials, equipment and training for advanced composites with next-day shipping and expert technical advice. - Easy Composites

Prepared the surface, and you can see I've dressed one of the distorted inserts.

Cleaned with acetone, glued and clamped insert;

And here it is after sitting in the house for a couple of days to fully cure. Just to dress it (as it too had distorted) and re-fit the reapired motor.

 

[Gauss Guzzler]

Looks fine to me. A little bit of surface cracking around a discontinuity like that in a very thick carbon section is not uncommon or concerning.

I'm curious to see a pic of the insert but I'm guessing it's basically a thick stepped stainless steel washer shaped like this:

If so, it's basically a non-structural spacer glued in there to fit your motor width and provide a hard surface for the bolts to pass vertical loads into the end-grain fibers in the carbon holes. Over-torquing will cause the inserts to spin and break their glue joints, allowing some tiny rattle that will gradually worsen until needing the repair you have done. In the future you should use the motor to position the insert rather than clamping it to the frame so that the bolt doesn't end up stressing anything into position when tightened.

 

[Gareth]

Cheers Gauss.

They are soft aluminium. I think the screw heads sit onto carbon and the thread through the insert. I think I have crushed and lost some of that carbon on 4 mounts. The insert doesn’t spin it distorts. I clamped it into position to ensure a good a bond. Consensus seems to suggest 11Nm with thread lock as the correct torque figure.

I’d really need to see a brand new frame to fully understand the extent of the damage that I’ve now got.

I definitely have some damage but I hope you are right that it will still be fine in use – fingers crossed.

 

[Gauss Guzzler]

I don't think there was any carbon there. It would be difficult to mold with that complexity, the sharp details would be weak, and it's not good practice to allow bolt heads to contact carbon. Plus, it would require a very large carbon feature to be reasonably structural so the path of destruction would be apparent.

It looks to me like this is solid carbon that was drilled after curing:

Then this metal insert was glued into the hole, not intended to take significant side/side forces - only vertical forces from pedaling/landing. The side/side forces are small and managed simply by the fact that the frame surrounds the motor. The chipped edges are just the glue line, covered in paint.

Your screws came loose at some point and mangled the insert. That's not from overtorquing.

 

[Gareth]

Cheers Gauss.

The first image you have referred to, there is a good wee bit of carbon missing – that hole has a smaller diameter to the inside of the frame, and a larger diameter to the outside of the frame. But it does seem that the main bond for the insert is on the inside of the frame. Which is why I’m hoping things will be OK. It is just a worry that the insert became dislodged.

My screws have never come loose. All the damage is from over torquing. Look at the first insert photo. That insert should have a flat face – the force of the over torque has distorted it.

We think the correct figure is 11Nm. The bike shop told me 40Nm. I should have known better. So, I started torquing them up bit by bit. I got to 30Nm on several screws, and well you know when things just don’t feel right. I knew at that point I’d done damage. I backed it off a bit and left it. 180 miles later when the motor failed and took it out – well you can see what I found.

But yeah hopefully you are correct about the moulding and that the screw contacts only with the insert and does not sit on carbon.

Anyway – I’ll just keep riding and see what happens. Fingers crossed.

 

[Gauss Guzzler]

Ah, I see what you mean about the carbon hole diameter - there is a step change to a smaller diameter in the insert region. I suspect they molded the large outer diameter so that it would look nice when painted, and it might even be hollow or foam-core in that region to save weight. But the smaller diameter should be solid carbon and either drilled or reamed to rough it up for bonding to the insert. Usually drilling is better, counterintuive as it may be.

And I see the mushroom distortion of the inserts, yes definitely from overtorquing. But one insert has an elongated bolt hole which suggests it was stressed by a loose bolt moving around within the insert.

 

[Gareth]

Nope no loose screw. The inserts had crushed into the threads with the force, I had to file them out so the thread clears rather than threads through which would be incorrect. The inserts have been squashed and spread. There will be a clearance tolerance to allow for motor bracket/frame hole position I would assume, plus naturally thread high and low, so that’s just a little bit directional spread from the over torque on the soft aluminium.

 

[MrPeaski]

I have posted a few times regarding the torque settings for the T40+ bolts, and to be honest I got the numbers from this thread where the OP over torqued the bolts from poor information.
Have a feeling I won't be riding my bike any time soon >.>
Post #71 is where I got the figures of 11 Nm and 6Nm.

Whenever I've taken my motor out (2020 160 Action Team) I've only ever torqued the T40+ bolts up to 11Nm and so far not had any issues with it creaking, and the frame mounts are still good.

I have reached out to the EU distributor (Oneway Bike) via their contact page for definitive torque settings so that we all know the real figures to take out any guess work.
Lets see how long it takes and if we do get the correct information.

 

[Gareth]

Cheers MrPeaski,

Yeah I’ve seen that thread now, and others. Would be nice to see a figure on a Cube document, but the 11Nm has been mentioned a few times. I’ve left mine at 13Nm as I don’t want to disturb it now.

Good to hear that figure is working just fine for you.

I have reached out to the EU distributor (Oneway Bike) via their contact page for definitive torque settings so that we all know the real figures to take out any guess work.

I’d love to get hold of a set of OE inserts just in case I have any further issues. Wonder if they would send me a set.

 

[MrPeaski]

I’d love to get hold of a set of OE inserts just in case I have any further issues. Wonder if they would send me a set.

Highly unlikely, they'd have to come from the actual frame maker, probably in the far east somewhere.
I think what you have already done is about as good as it'll ever be now.