Levo SL Gen 1 AXS Electronic Shifting on Levo SL or Any EMTB Really

[Planemo]

Bosch cuts power when combined with shimano di2 shifters.

I did read somewhere that even without Di2, the Bosch Gen4 system 'notices' the slight torque difference when changing gears and reduces output. I can't say I have noticed this as it is habit that I ease off when changing and I really struggle not to do it in order to test this theory. I have a feeling that even if true, it would work better with upshifts than down as the torque drop is more noticeable to the motor when upshifting.

As someone mentioned above, I would really like to see a total and deliberate shutoff when changing (like a motorbike/car) and it seems Di2 is the answer (I presume it sends a signal to the motor?) but out of my price range at the mo. Until then, the best we can do is still try and ease off a bit (which is hard on a hill I grant you) or try and speed up just before easing off for the gear change but again this isn't easy if the hill is ruddy steep. I am OCD about stressing my drivetrain but sometimes it just has to happen

 

[aarfeldt]

When a motor continues to provide torque after you stopped pedaling, this is called "overrun".
This is normally usefull, when you have learned to use it.
Sometimes it's not that helpfull - like shifting on a hill when you have lots of torque and want to make a fast shift to not loose too much speed.
If you have a "acceleration" setting, try to turn it down.
It helped me (even though it's for another situation).

Another tip: if I need to go over a top of a hill, and I need to keep momentum, I will add power for a short time, to avoid a bad high torque shift.
Works for me.

 

[Butane]

Honestly some extremely helpful comments here. Over-run or whatever you want to call it is definitely my issue. In summary, it seems most E-mtb motors continue to give torque for some set amount of time after you stop pedaling to make things feel smoother, and this means you have to wait some additional time to re-apply torque than on an analogue mtb.

 

[Jimbo Vills]

Honestly some extremely helpful comments here. Over-run or whatever you want to call it is definitely my issue. In summary, it seems most E-mtb motors continue to give torque for some set amount of time after you stop pedaling to make things feel smoother, and this means you have to wait some additional time to re-apply torque than on an analogue mtb.

so you haven’t figured out that e bikes have over run but want to tell everyone it’s not your technique and you know how to shift a bike.

then call people snobs and tell them they have nothing to add to the discussion.

Wow...

As others have suggested, it’s different to a normal bike, and you can learn to use the over run to time the shifts differently.

Let us know how the AXS system pans out for you. ??

 

[Butane]

so you haven’t figured out that e bikes have over run but want to tell everyone it’s not your technique and you know how to shift a bike.

then call people snobs and tell them they have nothing to add to the discussion.

Wow...

As others have suggested, it’s different to a normal bike, and you can learn to use the over run to time the shifts differently.

Let us know how the AXS system pans out for you. ??

You didn't, and still don't, have anything to add to the discussion.

 

[Jimbo Vills]

Good luck on your journey of mechanical enlightenment ??

 

[Zimmerframe]

Bosch cuts power when combined with shimano di2 shifters. You'd think shimano would catch up with the ep8 ..... but it appears they didn't. Weird.

The e8000's were supposed to pulse the power for 0.1 second if you had the di2 running through the motor. Not sure if it ever really did this or not, but that's what was supposed to happen. I'd imagine they'd have the same on the ep8, unless they found it didn't actually work as expected or it never really did it in the first place.

How does the Bosch do it if the DI2's not wired through it ? It wouldn't know when you've pressed the shifter ?

So that takes me to the other part of my question - does the sl / mahle motor deliver power in a typical emtb pulse ( dropping assistance around the 6/12 crank position) . The orbea rise adverts give a nice graphical representation of this phenomena with the ep8 rs .

Not heard of this either ? There is no crank position sensor, only a torque sensor. How would it know where your cranks are ? Even if it was factory calibrated, if you took your cranks off, who's to say you'd put them back in the exact same place ? I guess you could use the torque sensor to work out where it thinks you are within a pedal stroke by mapping the power ? Curious and Interesting !!

@Butane You might be experiencing Over Run. Several motors have this on purpose, Levo's/SL's and others. The idea is that the motor continues to spin for a fraction of a second when you stop pedalling to help you over a rock for instance. It might be a combination of that and how you're reducing your power that means you're still giving the sensors enough input that they're presuming you still want x amount of assistance.

There's all the other factors too which have been suggested, but also chain/cassette wear, Indexing, SRAM/Shimano technique bias.

As suggested I'd change the hanger for the tiny cost. I had something similar the other week, fine on the flat, only on hills. I was convinced it was fine - it wasn't.

 

[Damon Hart]

Absolutely love the AXS system.
Using squirt wax chain lube I've managed to get 1300 miles out of my first chain used over the winter from October to late March. Will probably change the cassette when I change the chain next.
Shifting is very smooth and I do back off when changing gear. Turbo under high load will sometimes give a crunch.
I find that thinking £1500 every time I shift focuses the mind ?
Great system and I highly recommend it.

 

[Mohawk3a]

I have an sl with an axs eagle 1x12 drivetrain, and a trek rail with a mechanical Xtr 1x12 drivetrain. Both are great but the Xtr shifts better under torque.

 

[Mikerb]

Something else the Op does not seem to have learnt despite years of analogue MTB experience is PLAN AHEAD!! There should be very few emergency downshift needs if you are actively planning the trail ahead.
The torque sensor has a slight delay time which when added to the mechanical time required for the sprag to disengage means there is about 25% to 30% crank rotation "overrun".............something every EMTB rider knows about!! Typically the higher the assist mode the longer the overrun but it does vary between motors.
I have the a Bosch motor Whyte and a Brose motor Levo. Overrun is there in every assist mode with the Levo, however on the Bosch ( or at least mine) there is little or no overrun in "EMTB" mode and that does mean it is easier to change gear with just a small lessening of power on the cranks. The overrun is however there on Turbo........and very useful it is as well, especially given the low BB of the Whyte!.

Someone mentioned the 6/12 o'clock crank position. The only thing special about that position is that it is the point of crank rotation where rider applied torque is at its lowest ( assuming a circular chain wheel). If the motor has quick disengage ( ie no overrun) it would be the best position to change gear but it would be difficult to time on anything other than a low cadence!

 

[Pdoz]

Someone mentioned the 6/12 o'clock crank position. The only thing special about that position is that it is the point of crank rotation where rider applied torque is at its lowest ( assuming a circular chain wheel). If the motor has quick disengage ( ie no overrun) it would be the best position to change gear but it would be difficult to time on anything other than a low cadence!

My 6/12 ? Myth? Developed from threads on chain wear from poor shifting about 3 years ago. One of the more reliable members suggested shifting in this position and it definitely helped me. Reflecting on the mechanics , it probably is a simplified way of ensuring backing off ? For what it's worth, I only started needing to rely on it when my cadence increased.

 

[johnf0246]

You didn't, and still don't, have anything to add to the discussion.

Butane I ride in an area that has a lot of up and downhill riding. I ride my wife’s SL on occasion when she goes skiing or pottery class. Her bike has the original NX group which works great going up gradually steeper uphills or downhill. She has a total of 3,733 miles on it, and the chain stretch is at 100% on the original drivetrain. I don’t plan on changing the rear cassette, front chain ring and chain until the bike doesn’t shift well going uphill.
Hope that helps.

 

[Butane]

I did a nice solid 3 hour ride today with all of this in mind and I had my analogue bike along with my Levo SL as I was riding with a friend. We traded bikes several times so I got a very good back to back comparison. I tested it out and it is definitely the over-run fucking with my muscle memory. There is clearly an additional fraction of a second of continual power output even with zero crank input which I believe is a useful feature in 90% of scenarios due to it feeling a lot smoother when it cuts off, but can throw someone off who is used to timing the shifts on an analogue. You have to adjust and compensate for this by waiting a fraction longer to shift and then reapply pressure to the cranks. I actually wish there was a slider in Mission Control for over-run duration because I would probably reduce it slightly.

 

[Swissrider]

It shifts fine on flat, it's really only moments where I am on a hill, and that hills grade increases so I have to drop another gear. Normally I would pedal hard for a second and then downshift while I let off torque on the cranks so that it shifts smooth. When I try that on my SL, when I let off on the torque it still feels like the motor is applying a lot of torque to the crank even though I'm not, and it make the shift crunchy.

It sounds as if you have the right technique, which works on an analogue bike, but your timing is out. Once you stop peddling the motor keeps driving for a few metres. Some like this feature, some don’t but it does mean changing down is tricky. You have to wait much longer on an ebike for the power to come off then you can shift down smoothly without crunching. Electronic changing isn’t going to help, the change is quicker but you’ll still have to delay your change after stopping peddling. Actually the technique is subtler than stopping peddling, you need to reduce power on the pedals just to the point that the motor is no longer engaging. This works well on relatively gentle hills but is difficult on a steep technical section as if you reduce peddle pressure for long enough for a smooth downshift then you may well come to a stop! Anticipation is the key but it isn’t always possible so occasionally one is bound to get that horrible crunching sound which greatly upsets my mechanical sympathies. I think that those of us brought up on analogue bikes have a real aversion to loud crunching gear changes and assume that our chain is going to break any minute but actually transmissions are amazingly robust and can quite easily withstand the odd crunchy gearchange. I get at least 2000k out of my chains and have never worn out a casette or chain ring (I’m lucky enough to live in a place which is neither wet nor dusty) and most of my gear changes are relatively smooth and quiet.

 

[Stuart]

I have a 2021 Levo SL. It came with the SRAM 11-50 rear cog and cable shifting. I found the shifting a bit slow as you have to push the levers quite far to make a shift.
I switched to the Eagle GX AXS wireless and also to an Eagle 10-52 cassette.
i really like the speed of the shifts - you touch the rocker switch and the gear change is instant.
I reduce pressure on the pedals when I shift to reduce stress on the chain and gears.
I have ridden about 600 km since I bought the AXS set with no issues to date.
You can customize the controls so that one touch of the rocker will shift 2 or 3 gears at a time, but SRAM says you will void your AXS warranty if you turn this feature on for an e-bike - too much stress on the components with the torque the motor adds. But you can tap the rocker multiple times much faster than a cable shift when you need to gear down in a hurry.
I would say the electronic shifting is a luxury, but now that I have it I would not want to go back to cable shifting.
Two other features: there is a micro-adjust feature where you can make tiny changes to the derailleur position to get the smoothest and quietest gear changes; and, I can see which gear I am in displayed on my Garmin Edge 1000 bike computer. Also the Garmin shows me the battery level in the derailleur.
The battery is supposed to last for about 20 hours of riding before needing to be recharged, but I ride around 10 hours a week, and I shift often to keep my cadence around 85 - 95; and the battery lasts at least 3 weeks between charges.

 

[Manitunc]

I used a shimano xt drivetrain with no issues. Switched to gx axs. Now have issues of chain jumping to higher gear from largest 3 cogs. And yes, the axs derailleur is adjusted properly. Have to hold shifter down to keep chain from up shifting on climbs. Works perfectly on stand though.

 

[Gyre]

I used a shimano xt drivetrain with no issues. Switched to gx axs. Now have issues of chain jumping to higher gear from largest 3 cogs. And yes, the axs derailleur is adjusted properly. Have to hold shifter down to keep chain from up shifting on climbs. Works perfectly on stand though.

Check your B-tension setting. Try to bring in the jockey wheels closer to the cassette, readjust the micro adjustments for the smaller cogs and make sure the wheels don't interfere with the largest cogs or rumble against them. Yes, SRAM has the tool that determines their ideal B-tension, but I'd take something like that as a starting baseline and nothing more.

If your B-tension is going out of range, your chain length might be off. Some people report needing to shorten their chains when switching to AXS from Shimano, so you might want to redo the length measurement. I seem to have gotten away with not shortening my chain but YMMV.

Another possibility is maybe the derailleur hangar is just a little bit tweaked. If you can't find any other solution, take it to a shop and have them use their hangar alignment gauge.

 

[RebornRider]

In addition to what Gyre wrote, remember that the only way a derailleur/sprocket system can shift is if the *outside* of the chain links contact the adjacent sprocket. If the chain is running down the middle of a sprocket, there is no way for the chain to jump to an adjacent sprocket. I've found that improper cable tension can cause the chain to rub on adjacent sprockets when I'm on the largest sprockets.

Edit to say that cable tension affects the alignment of the derailleur jockey wheel and the cassette sprockets. If the jocket wheels are out of alignment due to incorrect cable tension adjustment, then then jockey wheel will shift the chain away from the center of the sprocket. If the jockey wheel pushes the chain far enough, the chain will try to jump over to the next sprocket.

Since you just made a major drivetrain change, I'll bet lunch money that you have an adjustment problem. B tension, low limit, high limit, cable tension. When all of these are adjusted properly, my SRAM drivetrain shifts smoothly, quietly (assuming I back off on the torque!), and reliably.

 

[Manitunc]

No cable on AXS system. You set it with a guide. Shifts perfectly on stand. Only under load uphill or in rough does it try to upshift. Also no reason it should stay in gear if I hold the shifter down but it does. Will try b tension screw to get chain closer

 

[RebornRider]

Only under load uphill or in rough does it try to upshift.

This is exactly the problem I fixed by adjusting cable tension. Your system must have a way to adjust the position on the jockey wheel relative to the cassette sprockets.

BTW, my system also shifted well on the stand. I only got the horrible chain grunch sound on steep climbs in 1st or 2nd gear. Now that the jockey wheel alignment is fixed, the chain grunch sound is gone.

 

[Gyre]

This is exactly the problem I fixed by adjusting cable tension. Your system must have a way to adjust the position on the jockey wheel relative to the cassette sprockets.

AXS has a "micro-adjust" feature that's equivalent to tweaking cable tension with a conventional shifter's barrel adjuster.

 

[Mikerb]

If you have the bike on a stand to adjust B tension keep in mind that the rear triangle will be hanging whereas when you ride the rear triangle will be at the shock's SAG point.............which is why B tension setting usually requires the shock to be deflated to its normal SAG point.

 

[Manitunc]

I set it at my dealer while I sat on the bike, so should be at sag, but I will adjust closer and try

 

[RebornRider]

If you have the bike on a stand to adjust B tension keep in mind that the rear triangle will be hanging whereas when you ride the rear triangle will be at the shock's SAG point.............which is why B tension setting usually requires the shock to be deflated to its normal SAG point.

Because I was wondering about this, I shot a closeup video of the derailleur while I alternated between standing over the bike, sitting on the seat, and standing on the pedals. The derailleur jockey wheel to largest cassette sprocket distance changed by a very small amount. I guess this varies with suspension geometry - this is on a regular Levo, not an SL.

BTW, I didn't just deflate to the sag point cuz I have a coil.

 

[Mikerb]

B tension gap is often only c10mm in the first place so even 2 mm difference is 20%! You are right in my experience with the Levo that up to 30% SAG only makes a small difference but it can be more critical on Eagle for example compared to 11 speed GX and on bikes with different rear triangle designs.

 

[Duke]

I've changed to an axs at my comp.
It wont help you much with your problem.
Because the motor is still pushing a while after you stop pedeling it will make some shifting noise.
Otherwise you have to change the support of the motor push in the mission control app.

 

[Bike Rider 007]

All,

I just bought a 2021 Levo SL Comp Carbon and have taken it for a few rides. I've noticed that it is extremely difficult to downshift when going uphill (ya ya downshift before you hit the hill but what about when the hill changes grades mid climb?) without putting a lot of strain on the drivetrain. Even if I lessen my torque on the cranks during the shift, it still feels like the assist is putting a ton of stress on the chain and cassette. I have a feeling this means I'll be swapping chains and cassettes at a ridiculous rate because I seriously can't figure out how to shift without too much torque. I am thinking that an AXS shifter is a must on these bikes in order to maintain drivetrain longevity, because they perfectly time the shifts to put as little stress on the chain and cassette as possible. They just came out with the GX AXS upgrade which is identical to the X01 AXS system except it is made of steel instead of aluminum, which I'd prefer anyway because steel is more durable and I think that's better for the additional torque involved with E-Bikes.

What are your thoughts on this? Is AXS a must if you want your drivetrain to last any reasonable amount of time?

Thanks,
-Butane

Can confirm you will go through chains quicker on the SL vs analog bike. I just crossed 1800 miles and just put on my 3rd chain.

 

[johnf0246]

Can confirm you will go through chains quicker on the SL vs analog bike. I just crossed 1800 miles and just put on my 3rd chain.

Bike:

How worn out were the chains and were you having shifting issues? My 135 lb. wife has 3,400 miles on her original NX drive train and the chain indicates over 100% wear, but still shifts nicely with no obvious shifting issues or chain suck.

I see no reason to change out the drive train until she experiences shifting issues.

 

[Bike Rider 007]

Bike:

How worn out were the chains and were you having shifting issues? My 135 lb. wife has 3,400 miles on her original NX drive train and the chain indicates over 100% wear, but still shifts nicely with no obvious shifting issues or chain suck.

I see no reason to change out the drive train until she experiences shifting issues.

they were completely stretched out, I am 230 lbs with kit and I did notice shifting issues which is why I changed it each time. Im on the stock GX derailleur.

 

[RebornRider]

Can confirm you will go through chains quicker on the SL vs analog bike. I just crossed 1800 miles and just put on my 3rd chain.

My understanding is that chain wear depends on:

• How much torque you put through the chain
• Do you ride when the chain is gritty
• Do you keep the chain lubricated
• Probably some other factors

I think it's nearly impossible for us to compare chain wear because we are different weights, have different riding styles, ride in different environments, and have different bike maintenance habits. My chain life will probably not predict your chain life.

That said, because most of us will put more torque through the chain on an ebike than we would on an analog bike, we should expect to get fewer miles out of the ebike chain than the analog chain.