Will introduce me. I have my mp3 for 2 years now. I use the mp3 mainly for my work. I hope you can provide me with good advice.

Problem: Have a Yourban 300, which does not sound strange at cold start, but after 3 to 4 minutes I hear a separate sound from the cart side. Can not figure out where it comes from. When I turn my rear wheel I do not hear anything weird. Oil is also up to standard.

Solution: what can I check now? What do you think it is, can understand that it is difficult at a distance. Here is a video of the sound: