I recently took apart my rear derailleur as it was on a 10 year old bike and really old and stiff. So I thought I would unscrew both jockey wheels and clean them, they had a silver bit either side, ...
I had a mild spill today on my new bike, which put the (Tiagra) derailleur cage a little bit out of line. With some bending and eyeballing, I got the two jockey wheels lined up 'almost' perfectly ...
I want to put a new Sram X7 instead of killed one, should I open the chain (if I have no chain lock) or it's better to open the derailleur?