Mahle x35 queries

[scimmiamagia]

Hello

New to the forum.

I have recently acquired a gravel bike with a Mahle X35 motor.

I have a Brompton Electric so familiar with the 'eccentricities' of electric motors, but new to the Mahle.

Interested to know whether the 'tugging' I feel from the rear wheel (motored wheel) is normal when riding at around 16mph. The tugging is not really rhythmical, otherwise I would suspect torque sensor or similar.

There is limited information on the app that would show we what's happening in the motor but it does feel like the motor is turning on and off.

I know they are supposed to turn off around 15mph, so wonder if it is not turning off completely and therefore what I feel is power/no power/power/no power.

Any thoughts welcome.

 

[matthewslack]

Almost certainly the effect of hitting the assistance speed limit. The speed it is happening at is a strong clue to that.

From what you say, this system is a torque sensored rear hub motor? All you are seeing is an imperfect algorithm around the cutoff power management.

The cutoff is more sudden than you expect, perhaps you respond by putting in a bit more effort to maintain speed, then when speed drops below limit, power comes back in based on that increased input, so with a bit of a bang, and so on.

My own experience of torque sensored albeit mid-drive, has me thinking this is completely normal but is made harsher if you are using the higher assistance levels.

 

[scimmiamagia]

Thanks @matthewslack It is a bit annoying. Was wondering of this is typical of this motor. It is happening in the highest assistance level.

 

[Bikes4two]

The Mahle X35 does not have torque sensing AFAIK - that is a feature that came with the later X20 motor.

 

[Bikes4two]

Thanks @matthewslack It is a bit annoying. Was wondering of this is typical of this motor. It is happening in the highest assistance level.

and

...what I feel is power/no power/power/no power.

I think that is exactly what you are feeling around the speed cutoff point.

I would have thought that the motor's controller should ramp down assistance smoothly (and vice versa on re-applying assistance). Maybe there are software upgrades to be had?

You say you feel it in 'highest assistance' - what is it like in lower assistance levels?

It may be that the cutting in/out of assistance is more obviously felt at the higher assistance level?

You could pose your question on the cycling UK forum too where there may be more X35 riders there than here given that the Mahle systems are more often used by those cyclists who only require occasional and low levels of assistance.

 

[Nealh]

Not a motor issue , just how the controller alogarithm's handle the cutting in and out at the speed cut off.
Different control systems deal with it smoother then others.

My Tongsheng is pretty smooth as are my KT's .

 

[sjpt]

I often point Cycling UK form members to here, but for once I'll put in a pointer the other way: try asking at

Electrically assisted pedal cycles - Cycling UK Forum

The style of the Mahle systems means there are not that many users of it here, but many more on Cycling UK.

That said, what you are feeling is almost certainly what the others have said, the result of going in and out of assistance with a poorly implemented control system. There may be settings or firmware updates available.