I have recently picked up a used bike to which according to the seller was rearly ever cleaned and never serviced.
I thought I'd take it upon myself to try and service the bike myself but have come across an issue with the rear derailleur when cleaning.
There seemed to have been a rubber grommet or something on both sides of the bottom pulley which had just broken apart and whilst removing the gunk maybe it was in poor condition or maybe I used excessive force.
Would this rubber be easy to replace and how can I find the part as I'm struggling?
would it impact my ride if I do not replace it?
Do I need to replace the derailleur?