Mahle SL 1.1/1.2 Re-Builds/Maintenance

Rafal K

New Member
Oct 14, 2023
7
21
Poland
The SL 1.2 is out in the wild with the '23 Levo SL.

From what we know so far, mountings and connections are all the same. It works with the existing battery and range extender (shorter 145mm instead of 160mm cable).

The motor is slightly larger due to the two piece aluminium honeycomb casing for noise reduction.

New 1.2 motor :

View attachment 113603

Previous (1.1) motor :

View attachment 113607

The torque sensor looks slightly different and you can see the casing on the drive side is thicker.

Hardware wise, from what we know so far, there were only slight changes made to the gears to make them slightly quieter.

There are claims that the new motor is slightly more efficient if used with the same settings as the 1.1 motor. This either means there were hardware changes that we're not aware of, or just with firmware they've managed to optimise the power delivery in a more efficient manner. Though they say they've re-tuned Trail 75% Support/80% Peak power and Turbo 100% support/80% peak modes, so this maybe where the extra "efficiency" comes from. Eco remains the same as previously at 35% support/35% peak power. If you want to use all the new power which is available, you'll need to up peak power to 100%.

Allan Cooke from Specialized (mountain bike marketing manager and all round amazing bike rider) suggested a lot was done on the firmware side, so it might be that the hardware changes were primarily for sound, but the power is from firmware. If that's the case, then theoretically Spesh could offer updates to existing owners, though that reduces incentives for existing owners to upgrade to new bikes.

Updating the firmware yourself wouldn't be easy as the Spesh systems are generally well secured even if you could get hold of the firmware, though potentially a third party could offer a "tuning service" if they knew what they were doing and weren't treading on Spesh toes.

Edit: put better picture of original motor.
Hey:)
Do you possibly have service manual for Mahle SL1.1 motor? You look like the man of knowledge;) I cant find any reasonable info on internet and just found this thread- which looks like most detailed info about those engines in whole internet;) I have 1.1. engine with mechanical issue (I thing clutch bearing is skipping) and where I live - nobody is repairing those motors- so I want to have a look myself- and trying to avoid big mistakes;) Cheeers. R
 

Zimmerframe

MUPPET
Subscriber
Jun 12, 2019
13,907
20,612
Brittany, France
Hey:)
Do you possibly have service manual for Mahle SL1.1 motor? You look like the man of knowledge;) I cant find any reasonable info on internet and just found this thread- which looks like most detailed info about those engines in whole internet;) I have 1.1. engine with mechanical issue (I thing clutch bearing is skipping) and where I live - nobody is repairing those motors- so I want to have a look myself- and trying to avoid big mistakes;) Cheeers. R
Hi,

Sorry, no I don't. I think the ebike motor centre repair the Mahle's and also have partners in other countries. It might be worth contacting them and seeing if they can help.


Cheers.
 

Rafal K

New Member
Oct 14, 2023
7
21
Poland
Hi,

Sorry, no I don't. I think the ebike motor centre repair the Mahle's and also have partners in other countries. It might be worth contacting them and seeing if they can help.


Cheers.
Hey:) So thank you for your replay. I actually bought repair kit from Italy- which is ebikmotorcentre partner (I didnt know that when I ordered it)
I menaged to open motor today- and it is fairly easy and looks reperaiable-as I suspected- sprag clutch fall apart completly (have no idea how I still could had ride yesterday) i did not finish to put it back together yet as one problem occured- one of new bearings delivered from EMC-doesnt quite fit. i will try to find better fitting one in local shop- or if fail-will put it back on old one- tomorrow morning. I will keep you infpormed if motor will work again. at the moment it looks like "not repairable- buy new" policy from Spec is BS.
 

Rafal K

New Member
Oct 14, 2023
7
21
Poland
SO. I finished- Motor is working-:))) and is working better than new... Quiet as death now. After inspecting inside- i know exactly what is making noise- Sprag clutch bearing- which is transfering torque from cranks to motor axis. it was not enough grease there- and it went completly rusty. (Little lubricant there has reason- it is actually holding all power from cranks) but it was possible too little. So I recomend to everyone who's motor is going noisy- if its after warranty- open it and clean and if necessery replace that clutch bearing. other parts does not show any sign of wear really
Last thing- after service- motor require calibration- which has to be done with specilized service sowtware, I did it at my local Spec dealer. takes 5minutes or less.
All the best!
 

JimVG

New Member
Nov 7, 2023
3
2
Gig Harbor, WA
Thanks for the information, Rafal. Can you give us more detail on the required calibration that you mentioned? Did your local dealer service technician perform it, or did you personally do it? What specifically was involved? The reason I ask this is because we have no local dealership, as Trek recently acquired all (3) local dealerships in our area.
 

Rafal K

New Member
Oct 14, 2023
7
21
Poland
Thanks for the information, Rafal. Can you give us more detail on the required calibration that you mentioned? Did your local dealer service technician perform it, or did you personally do it? What specifically was involved? The reason I ask this is because we have no local dealership, as Trek recently acquired all (3) local dealerships in our area.
Hey. Calibration has to be done on Specailized service software on Specialized service laptop. It was done by Spec technician. Bike was conected to computer via usb port in TCU unit. then there was message " motor require calibratrion" Calibratrion is done purely in service software- after chosing "calibration"- it is about making couple of stedy rotation of cranks- and that is it. Computer is showing- "calibration complete" and motor is working back.
 

JimVG

New Member
Nov 7, 2023
3
2
Gig Harbor, WA
Hey. Calibration has to be done on Specailized service software on Specialized service laptop. It was done by Spec technician. Bike was conected to computer via usb port in TCU unit. then there was message " motor require calibratrion" Calibratrion is done purely in service software- after chosing "calibration"- it is about making couple of stedy rotation of cranks- and that is it. Computer is showing- "calibration complete" and motor is working back.
Thanks for the detailed reply.
 

Streddaz

Active member
Jul 7, 2022
276
389
Tasmania
SO. I finished- Motor is working-:))) and is working better than new... Quiet as death now. After inspecting inside- i know exactly what is making noise- Sprag clutch bearing- which is transfering torque from cranks to motor axis. it was not enough grease there- and it went completly rusty. (Little lubricant there has reason- it is actually holding all power from cranks) but it was possible too little. So I recomend to everyone who's motor is going noisy- if its after warranty- open it and clean and if necessery replace that clutch bearing. other parts does not show any sign of wear really
Last thing- after service- motor require calibration- which has to be done with specilized service sowtware, I did it at my local Spec dealer. takes 5minutes or less.
All the best!
That's good to know.
The 1.1 motor in my Levo SL is running quite well so far with over $7000km on it but I have had what I think may be a slipping of the sprag clutch. It's only happened a couple of times but usually when I'm descending and standing up and cranking. Feels like a chain slip but I've got a new chain and cassette, so I'm fairly sure it's not that.
Did you buy the full bearing kit and service part seals?
 

Rafal K

New Member
Oct 14, 2023
7
21
Poland
That's good to know.
The 1.1 motor in my Levo SL is running quite well so far with over $7000km on it but I have had what I think may be a slipping of the sprag clutch. It's only happened a couple of times but usually when I'm descending and standing up and cranking. Feels like a chain slip but I've got a new chain and cassette, so I'm fairly sure it's not that.
Did you buy the full bearing kit and service part seals?
Hey. It was same in mine. Only started to “skip” pedals occasionally- when very strong kick/stroke was applied to cranks. Then in period of 2months- it become more and more frequent and started to be regular and annoying thing. When I opened bearing- it was completely desintegrated… I couldn’t believe it was working. Answering your question- I bought and replace whole kit- however only realy broken part was sprug clutch. So if you have time you may open motor- then decide what actually has to be replaced. I would say rubber seals has to be replaced for new oneas well -as you may have problem with taking them out without bending them (they are metal reinforced rubber- and fitting tight- I bent them when removing)
 

ilfer

New Member
Nov 8, 2023
3
8
Germany
Hi there! First of all - thank you all for this thread. I own a Levo SL 2020 and after testriding a 1.2 recently, I was quite keen on the really quiet 1.2 motor. Not because of the slightly more power, but regarding the less noise.
@Rafal K - really great that you mentioned your motor overhaul. It also got noticed in another forum I found via google, where they also posted a guy from italy and his SL 1.1 overhaul, he posted on youtube! He seems to have had a rusty sprag clutch bearing too. As my SL 1.1 is quite noisy too, I think I order that bearing and do an overhaul by myself over the winter...


Best regards from Germany! :)
 

JimVG

New Member
Nov 7, 2023
3
2
Gig Harbor, WA
To see the closed caption translation from Italian to English, from the YouTube video click the “CC” in the outlined square box at the top-right of the screen. Then click the gear icon to open settings and select “Captions”, then select “Auto-translate”, then select “English”. Now play the video. English translation is now in closed caption in the lower portion of the screen.
 

Streddaz

Active member
Jul 7, 2022
276
389
Tasmania
Hey. It was same in mine. Only started to “skip” pedals occasionally- when very strong kick/stroke was applied to cranks. Then in period of 2months- it become more and more frequent and started to be regular and annoying thing. When I opened bearing- it was completely desintegrated… I couldn’t believe it was working. Answering your question- I bought and replace whole kit- however only realy broken part was sprug clutch. So if you have time you may open motor- then decide what actually has to be replaced. I would say rubber seals has to be replaced for new oneas well -as you may have problem with taking them out without bending them (they are metal reinforced rubber- and fitting tight- I bent them when removing)
That great, I think I'll be ordering that bearing an O-rings at least!
Hi there! First of all - thank you all for this thread. I own a Levo SL 2020 and after testriding a 1.2 recently, I was quite keen on the really quiet 1.2 motor. Not because of the slightly more power, but regarding the less noise.
@Rafal K - really great that you mentioned your motor overhaul. It also got noticed in another forum I found via google, where they also posted a guy from italy and his SL 1.1 overhaul, he posted on youtube! He seems to have had a rusty sprag clutch bearing too. As my SL 1.1 is quite noisy too, I think I order that bearing and do an overhaul by myself over the winter...


Best regards from Germany! :)
Great link, I'll certainly be watching that one!

So good that you can rebuild a motor rather than replacing the whole unit when it's just something like a sprag clutch.
 

sadzo

Member
Mar 9, 2022
6
5
Slovenia
SO. I finished- Motor is working-:))) and is working better than new... Quiet as death now. After inspecting inside- i know exactly what is making noise- Sprag clutch bearing- which is transfering torque from cranks to motor axis. it was not enough grease there- and it went completly rusty. (Little lubricant there has reason- it is actually holding all power from cranks) but it was possible too little. So I recomend to everyone who's motor is going noisy- if its after warranty- open it and clean and if necessery replace that clutch bearing. other parts does not show any sign of wear really
Last thing- after service- motor require calibration- which has to be done with specilized service sowtware, I did it at my local Spec dealer. takes 5minutes or less.
All the best!
Hi. Rebuilding the motor myself, and I have a problem with one of the bearings aswell. I can't push the spindle of the chainring through the bearing that is pressed in the driveside motor shell - seems like the seat of the bearing on the spindle is too wide. The spindle goes through to the last groove for safety ring, then it's too wide - unable to press it even with the bearing press, left alone with hands. Did you have the problem with the same bearing and what was the solution? I also measured everything and the bearing is supposed to be 35,00mm inner. The new one is exactly that but the old one and the spindle seat come at 35,15mm. Also wrote to Mahle and Specialized, waiting for their answers.

Thanks, Matic
 

Rafal K

New Member
Oct 14, 2023
7
21
Poland
Hey. I had same problem and actually I used old bearing in this point as was in perfect condition. And you right- I measured spindle as 35.1. Maybe there is possibility of cooling that spindle to shrink and then press it. But I doubt it. If I have to do another rebuild- I may consider some drastic action;) this may be little bug left by Mahle- they may some secret way of fitting- as original bearing spec is 35mm. So no way to fit it in standard way.
 

sadzo

Member
Mar 9, 2022
6
5
Slovenia
Hey. I had same problem and actually I used old bearing in this point as was in perfect condition. And you right- I measured spindle as 35.1. Maybe there is possibility of cooling that spindle to shrink and then press it. But I doubt it. If I have to do another rebuild- I may consider some drastic action;) this may be little bug left by Mahle- they may some secret way of fitting- as original bearing spec is 35mm. So no way to fit it in standard way.
Hi! Since then, I talked with Specialized and Mahle - both just replied that they don't deal with this sort of stuff so no help there. Then I talked with the guys from eBike Motor Centre and they told me that it is common for motor manufacturers to customize a bearing or two in the motor to some idiotic measures. Then they assured me that they specialize exactly in that and that every bearing is sourced that it should fit - ordered one and wainting it from Germany - should come in a few days. If even that wont fit, the only other option I see will be to mille inner race of the standard bearing to the right dimension.
Also, I tried heating the spindle and at the same time putting the bearing in the freezer. Managed to press it 1/3rd on the seat, then stripped the thread on the bearing press haha. Damaged the bearing also - it became stiff and hardly spinning so even if i could press it on, it wouldn't spin. Also talked with the local bearing specialist and they told me that 0.15mm is too big of a difference to get by with temperature and said the bearing needs to be adjusted (as much as 0.05 can be influenced with temperature).
Will update this after I get the bearing, hope it helps someone in the future.
 

Streddaz

Active member
Jul 7, 2022
276
389
Tasmania
Hi! Since then, I talked with Specialized and Mahle - both just replied that they don't deal with this sort of stuff so no help there. Then I talked with the guys from eBike Motor Centre and they told me that it is common for motor manufacturers to customize a bearing or two in the motor to some idiotic measures. Then they assured me that they specialize exactly in that and that every bearing is sourced that it should fit - ordered one and wainting it from Germany - should come in a few days. If even that wont fit, the only other option I see will be to mille inner race of the standard bearing to the right dimension.
Also, I tried heating the spindle and at the same time putting the bearing in the freezer. Managed to press it 1/3rd on the seat, then stripped the thread on the bearing press haha. Damaged the bearing also - it became stiff and hardly spinning so even if i could press it on, it wouldn't spin. Also talked with the local bearing specialist and they told me that 0.15mm is too big of a difference to get by with temperature and said the bearing needs to be adjusted (as much as 0.05 can be influenced with temperature).
Will update this after I get the bearing, hope it helps someone in the future.
I wonder if it would be worth machining the spindle down to size? That's if it can be removed to do so.
 

sadzo

Member
Mar 9, 2022
6
5
Slovenia
I wonder if it would be worth machining the spindle down to size? That's if it can be removed to do so.
I thought that too. It can be done, the spindle can be removed completely and the seat is in a quite convenient spot. But I would still rather machine the 20€ bearing than the spindle that - from the responses I got for the bearings from Specialized and Mahle - can't be replaced.
 

Streddaz

Active member
Jul 7, 2022
276
389
Tasmania
I thought that too. It can be done, the spindle can be removed completely and the seat is in a quite convenient spot. But I would still rather machine the 20€ bearing than the spindle that - from the responses I got for the bearings from Specialized and Mahle - can't be replaced.
Well, you are right. If it's possible to machine the bearing down, that would be the least risky part to do it on. I've never machined a bearing, it would be pretty hard stuff and tricky to hold but I'm sure someone should be able to do it.
 

Streddaz

Active member
Jul 7, 2022
276
389
Tasmania
SO. I finished- Motor is working-:))) and is working better than new... Quiet as death now. After inspecting inside- i know exactly what is making noise- Sprag clutch bearing- which is transfering torque from cranks to motor axis. it was not enough grease there- and it went completly rusty. (Little lubricant there has reason- it is actually holding all power from cranks) but it was possible too little. So I recomend to everyone who's motor is going noisy- if its after warranty- open it and clean and if necessery replace that clutch bearing. other parts does not show any sign of wear really
Last thing- after service- motor require calibration- which has to be done with specilized service sowtware, I did it at my local Spec dealer. takes 5minutes or less.
All the best!
How did you remove the sprag bearing from this housing?

The brass part seems to be pressed into the outer steel housing and I was worried about damaging it.
IMG_4127.jpeg
 

Streddaz

Active member
Jul 7, 2022
276
389
Tasmania
After breaking the seat stay and having to wait for the replacement, I decided to rebuild the motor. Mainly as I thought the sprag bearing was on its way out, as it has slipped under full standing up cranking once or twice. The motor has done over 8300km so not a bad effort and other than that occasional slip, it still runs great.

I ordered a bearing and seal kit from Ebike Motor Centre and had a crack at fitting new bearings and seals.

No going back now.
1707862772592.png


I bought the full kit but after cracking it open found that everything was looking really good inside so just decided to replace the sprag bearing, and the crank bearing and seals.
1707862814771.png

1707862842979.png


The sprag bearing looked to be a little damaged. I have heard of them falling to pieces when people pull them out. The brass ring was a bitch to get out and its pressed in. It holds the sprag bearing in the housing. Ended up getting it out eventually by making a ring that the housing could sit in and I could tap the old sprag bearing from behind, to punch the brass ring out.
1707862870711.png


New sprag bearing installed.
1707862987372.png


It's all back together now and running pretty well. Sprag bearing seems to be doing its job, but I do have a bit of a noise like when your chain rubs on your chain guide coming from the motor under full load. I have some more plastic gear grease coming and will open it up to see if I can work out what is causing it and lube everything up some more.
Replacement black seat stay, new pivot bearing kit, derailleur, hanger and chain. (commuter wheels in place)
1707863019169.png
 
Last edited:

KnollyBro

E*POWAH Elite
Dec 3, 2020
894
2,219
Vancouver
After breaking the seat stay and having to wait for the replacement, I decided to rebuild the motor. Mainly as I thought the sprag bearing was on its way out, as it has slipped under full standing up cranking once or twice. The motor has done over 8300km so not a bad effort and other than that occasional slip, it still runs great.

I ordered a bearing and seal kit from Ebike Motor Centre and had a crack at fitting new bearings and seals.

No going back now.
View attachment 406894

I bought the full kit but after cracking it open found that everything was looking really good inside so just decided to replace the sprag bearing, and the crank bearing and seals.
View attachment 406895
View attachment 406896

The sprag bearing looked to be a little damaged. I have heard of them falling to pieces when people pull them out. The brass ring was a bitch to get out and its pressed in. It holds the sprag bearing in the housing. Ended up getting it out eventually by making a ring that the housing could sit in and I could tap the old sprag bearing from behind, to punch the brass ring out.
View attachment 406897

It's all back together now and running pretty well. Sprag bearing seems to be doing its job, but I do have a bit of a noise like when your chain rubs on your chain guide coming from the motor under full load. I have some more plastic gear grease coming and will open it up to see if I can work out what is causing it and lube everything up some more.
Replacement black seat stay, new pivot bearing kit, derailleur, hanger and chain. (commuter wheels in place)
View attachment 406898
Good to hear you got it all back together and running well! I am not sure if its just me (or at this moment) but none of the images are showing up. Any idea why?
 

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