Superdelite engine jerk when kicking-in

[RMSDivine]

Hello everyone, I have recently serviced my SD after 1200Km for a checkup. The man updated the engine firmware to latest version.
About one week after this, my engine does an annoying "twitch" when kicking-in. No no noise at all. Never happened before.
I am sure this is not due to the firmware update, but I suspect that some parts in the engine aren't performing well.
Any clue?

 

[marcparnes]

Hello everyone, I have recently serviced my SD after 1200Km for a checkup. The man updated the engine firmware to latest version.
About one week after this, my engine does an annoying "twitch" when kicking-in. No no noise at all. Never happened before.
I am sure this is not due to the firmware update, but I suspect that some parts in the engine aren't performing well.
Any clue?

Is it possible to describe it with a bit more detail. I'm not sure what a twitch is.

Marc

 

[RMSDivine]

Sorry for my poor English, I mean that when you begin pedalling, you can feel like the first part of the movement is not assisted, then you feel the engine kicking in. I am not sure if this was happening before or not, but my impression is that either it wasn't happening at all, or the engine kicking-in was more soft and gradual.
The man at the service told me that the new firmware adds more torque than before but can this be noticed with this unseen twitch? And why after a week of usage?

 

[marcparnes]

Does it matter which assist level you’re in? Which gear do you start in?

Marc

 

[RMSDivine]

Will have a go, but in my opinion it will do this every time you stop pedalling and then you begin pedlling again...

 

[Jay Kay]

This is not normal. I had my Delite updated at its last service - no change other than a snappier motor. I’d get it checked out.

 

[RMSDivine]

It does this on every gear. Went to the shop, they looked a bit embarassed, don't know why!
I will contact Bosch & Riese Muller for an advise. The bike and the engine are both under warranty

 

[RMSDivine]

So I went to an authorised Bosch service support, and they got in contact with Bosch in Germany, who asked to set the firmware to 75nm and make a test. This was done by technician who tested the bike and said that the issue is less perceivable.
He then reverted settings to 85nm and studied the mechanics of the bike and noticed that the freewheel pawls number of the rear wheel (31) and the freewheel pawls number of the engine are different and this might cause the issue, or just maybe because the rear freewheel pawls number is low.

He said that freewheel pawls for professional mountain bikes can go up to a number of 400, to ensure that the grip is immediate without any gap when you begin pedalling.
I really don't know understand why this "gap" was not noticeable before the software upgrade, but I am quite unhappy as for this issue. Maybe I am just too obsessive!
Do you know if the Rholoff E14 shift suffers from this "gap" issue? I might consider asking the dealer to mount the kit if the cost is not prohibitive.

 

[RMSDivine]

Do you think this issue could be due to multiple pedal strikes? The crank arms are pretty firm, there's no "play" at all, but I wonder if the gears inside the engine got loosen somehow

 

[Jay Kay]

Does this happen in all power settings - eco, tour, sport and turbo? Or are you noticing it more in sport or turbo?

 

[RMSDivine]

I am noticing it with any setting, but lower gears seem to show this more than higher ones

 

[Jay Kay]

Hmmmmm, ok I wondered if you may have been in too high a power assist for the speed/terrain which can make the engine jerk someonewhat, but that doesnt seem to be the cause. Sorry, it was worth a shot raising it.

As I said above the motor, since your flash upgrade, is not performing as intended and I would be asking for a replacement under warranty (assuming your legal jurisdiction has such consumer laws).

What a pain, especially with COVID.

 

[ayamuz]

I am noticing it with any setting, but lower gears seem to show this more than higher ones

Did you find any solution for this? My Nevo3 just started doing this. :/

 

[JVBulman]

Did you find any solution for this? My Nevo3 just started doing this. :/

Have you checked the alignment of the spoke magnet and the speed sensor?

 

[ayamuz]

Have you checked the alignment of the spoke magnet and the speed sensor?

Just rechecked and it is in the correct position. I might be over focusing now but I also think the bike feels slower/tougher to pedal than it used to. Now I’m trying to find someone that’s able to take a look at it but no luck yet. My local bike shops apparently have no experience with Bosch. ¯\_(ツ)_/¯