Impulse/Daum motor. Pedal spin

Astrocan

Just Joined
Nov 6, 2021
2
0
I have a Kalkhoff with one of these motors which I bought second hand. I am very pleased with the build quality of most of the bike but this motor has packed in. Almost from day one I was finding false neutrals, the pedals would spin for a bit then suddenly engage with a crash which was clearly not what was supposed to be happening and made me fear for the mechanical parts that were takng the impact. I naievely put this down to poor adjustment of the Nexus hub and made several attempts to adjust it. However the situation deteriorated to the point where I could no longer rely on being able to get any forward motion at all and I eventually discovered that if I span the pedals, the belt did not move so the false neutral was inside the motor, not the hub. I am going to try for a warranty exchange but don't hold out much hope. Does anyone have any advice on what the issue might be and how to go about dismantling the motor to get to the problem? I assume that it must be some kind of clutch or pawl. I am a competent mechanic and have access to facilities that could make a fix but having the guidance of someone who has been down this rabbit hole before would be much appreciated.
Thank you
 

soundwave

Esteemed Pedelecer
May 23, 2015
15,973
6,292

the problem is the motor as they all fail so if it is more than 2 years old then the warranty will have run out.

peter does service those motors so should be able to help out with it.
 

flecc

Member
Oct 25, 2006
52,763
30,349
It's the pawls of the chainwheel's freewheel that have failed, a common fault with the Impulse units. Try Performance Line, recommended above by Soundwave, to see if they can help.
.
 

Advertisers