Hi, can anyone help with this problem please.
My wife has an EMU Step-Through mk1 bike bought in 2016. It has a Nexus 7 speed rear hub and a front hub motor which Emu tell me is a Shengyi 250w. It has a brand new 36v 14Ah/504Wh Li-ion battery.
Problem is an intermittent drive loss under load. On the flat or small inclines there is no problem the motor pulls well if a little noisy but I think that is normal. However, when going up a hill the motor will cut-out completely for 5/10 seconds before coming back for anything from 5 to 20 seconds before cutting out again and repeating this cycle. Very occasionally it will go all the way up a hill without any problem, especially if you don't pedal too hard/fast.
When the motor drive cuts, and you can hear the whine stop instantly, the display is still showing a full battery but the Wattage reading drops to zero. Makes no odds how full battery is.
Ideas I've had but discounted:
Knackered battery - hence new one but hasn't helped
Knackered motor - possible I guess but watching the Watts drawn it will often cut-out showing say 240W then start up again drawing 400W+ and pulling hard.
Local bike dealer suggested it may be the pedal crank sensor intermittently failing - but if so why only when under load? I've cleaned around the sensor and the magnets but made no difference.
My best guess is it's perhaps a sensor somewhere failing, maybe in the front hub motor, but my knowledge of Pedlecs mechanics is minimal.
Thanks.
My wife has an EMU Step-Through mk1 bike bought in 2016. It has a Nexus 7 speed rear hub and a front hub motor which Emu tell me is a Shengyi 250w. It has a brand new 36v 14Ah/504Wh Li-ion battery.
Problem is an intermittent drive loss under load. On the flat or small inclines there is no problem the motor pulls well if a little noisy but I think that is normal. However, when going up a hill the motor will cut-out completely for 5/10 seconds before coming back for anything from 5 to 20 seconds before cutting out again and repeating this cycle. Very occasionally it will go all the way up a hill without any problem, especially if you don't pedal too hard/fast.
When the motor drive cuts, and you can hear the whine stop instantly, the display is still showing a full battery but the Wattage reading drops to zero. Makes no odds how full battery is.
Ideas I've had but discounted:
Knackered battery - hence new one but hasn't helped
Knackered motor - possible I guess but watching the Watts drawn it will often cut-out showing say 240W then start up again drawing 400W+ and pulling hard.
Local bike dealer suggested it may be the pedal crank sensor intermittently failing - but if so why only when under load? I've cleaned around the sensor and the magnets but made no difference.
My best guess is it's perhaps a sensor somewhere failing, maybe in the front hub motor, but my knowledge of Pedlecs mechanics is minimal.
Thanks.
