HeyBike Mars error 21 on display

[Fde12341234!]

Hi,

When I start my HeyBike Mars, on the display I get Error 21. It all started when I was breaking for a stop sign and a tickling sound started to be heard from the rear tire and the breaks of the rear tire failed. Any help on error 21 would be great as this is my first electric bike.

 

[amberwolf]

the sound might've been something on the bike hitting wheel spokes, or it could've been brake pads catching in rotor holes before disintegrating, or a wire being caught in the caliper/rotor.

if it was a wire hitting the spokes or rotor was damaged, it could cause errors.

you'd have to check your manual for what 21 is for your system, but it's a common error message on other threads here you might be able to use info from to test yours. the list linked below is only looking at titles for the error, but you can do a search for posts as well if you don't see what you want in this list.

Search results for query: error 21

endless-sphere.com

 

[Fde12341234!]

Hi, so I have tried to open the controller box at the bottom of my HeyBike Mars, but every connection looked great. So I would say that the electronic part might be fine. The back tire still makes the noise, however, when I put WD-40 in the motor, it seems that the noise goes away… but then one day later it comes back. Any ideas?