Today as I was shifting between the 9th and 10th(last) cog, applying just slight pressure on the pedals, something very strange happened. The chain suddenly started slipping skipping(whatever is the correct term) on the 10 cog. It now happens all the time, even when the pedals are just slightly pressed. All 9 other cogs work perfectly. I constantly clean and grease my drivetrain, and the chain+cogs are not worn.
Here is a video which explains better:
I thought the H limit screw could've somehow moved so I tried to adjust it with no result. The chain doesn't "climb" on the 9th cog.
I also experimented with the B screw with no result. I also took the wheel off and cleaned the 10th cog and pulleys.
Any idea of what could have happened ? I can clearly see in the video what's happening but can't think of what could be the cause.
Thanks a lot
