Hi everyone,
I am attempting to change a 9 speed cassette on my bike. The cassette is worn but not crazily so. To assist, I am using a Park Tool SR-1 Sprocket Remover/Chain whip with Header. When I have done this in the past, the process has been smooth. Unfortunately, as soon as I apply any pressure to the lock rig, the chain on the chain whip keeps jumping off whatever cog I place it on to hold the cassette in place. I have had other people hold the chain whip and it still jumps off the cogs. I have only changed a few cassettes with the whip so it is in pretty new shape. A picture of the cassette is below. What is causing this? what is the solution?
Thanks,
Neil