I changed out my rear tire about a month ago. 10,000 miles. Shortly after I started getting what sounded like a scrubbing sound from the back of the bike when I hit a bump. I checked several times and could not see where the tire was scrubbing. This continued so I removed the tire and could not find any rub marks. 02-06-21 there was an odor of paint or something coming from the rear as relayed to me from someone behind me. 02-07-21 when leaving my home the scrubbing sound was a solid sound as opposed to just hitting a bump. I turned around and went home. I checked the rear diff and it was low so I added oil. 4+ ounces later it was full. I did ride the bike around the block and there was no noise except the bump into my drive. This morning we emailed the service manager of the dealership where the bike was purchased. They stated to bring it in and they could check to see if there was any metal in the diff. We are going for a ride on Wednesday and see what happens and go from there…. We really need to be checking the diff oil !!!!