Swapping rear derailer advice
What's the quickest/easiest way to swap a rear mech? I'm replacing existing sora rear with a 105 on a triple drive chain.
I don't have tools to break or join the chain so is my only option removing the mech jockey wheels? Any other ways?
To change the rear derailleur without breaking the chain, remove only the idler (lower) pulley. You may have to "scissor" the inner and outer cage plates apart a bit to get the chain through the locator tabs and that will loosen the pivot bolt for the jockey (upper) pulley but it isn't necessary to remove it.
Install the new derailleur, thread the chain through it, replace the idler pulley and be sure the pivot bolts on both pulleys are snug. Adjust as required.