Short story:
I'm facing a Suntour VX RD (
looks exactly like this one, as far as I can tell) with a frozen hanger attachment bolt. I've tried soaking oil in, and if I force it I can get it to reluctantly move, with an angry creaking noise. Is this just a case of waiting for the oil to seep in , or have to go with something specifically penetrating?
Long story:
So I came across this bike in the wild with a DSO (derailleur-shaped-object), or rather not even quite shaped like a RD, but more turned inside out. Looked exactly like it caught a spoke and tore the cage plate almost off, but no evidence of trauma to spokes or metal dork disk (extends at least an inch past 28T largest cog on 5sp). I wanted to be a good samaritan, so I left a note with my email on the bike saying I could help replace the RD. He got in touch, I found this Suntour VX on CL for only $8 and sent him to go get it, then he brought me the bike, I got the chain open and old RD off no problem (old RD had integral hanger), next step screw the VX onto a hanger I happen to have handy.
But at this point, I cannot screw it on because the bolt is froze. I cannot screw the hanger backwards onto the bolt, because of the b-screw tab. So unfortunately, I had to send this soul off to the bike shop to see if they can install this RD. Light chain oil from every direction did not set it loose, except the slotted lockring (?) was able to come out.
Further backstory, he got the bike from CL, it originally had some different RD on it (probably also Suntour, to match the FD and shifters), and one day it "just fell off". Some LBS (that I am not familiar with) replaced it with this super-cheap monstrosity about a month ago, it mysteriously got turned inside-out about a week and a half later, out of frustration and busyness he hasn't taken it back to the shop yet. I'm hoping they'll be cool and do what it takes to install this RD for him for free.
Unfortunately, I can't finish the job for him, as I'm heading out of town. Is there any advice that I can forward to this guy?