speedyspaghetti

Hey guys -

So today I went to replace the GXP crankset and bottom bracket on my VeloBuild VBR-022 to replace them with a Rotor 3DF crankset and Rotor 30mm BSA bottom bracket. I was able to unscrew the old GXP BB just fine, non-drive side of the new one went in just fine, but the drive side just will not go in. Yes, I am turning it correctly (counter-clockwise), it goes a tiny bit then just completely jams up. Looking at the threads (photos below) it does seem like the first couple threads are almost reversed or damaged? I don't know how this would have happened - I'm the original owner of the bike and I've had the GXP on there for 6 years with no issue. I did have to tighten it a few times - maybe I over-tightened it and messed up the threads? Do they look damaged to you guys?

LBS says they can chase the threads for $45 which kinda sucks and they can't do it for a week so I'll be riding my vintage steel until then, but man are bikes frustrating.

noodle soup

First of all, CLEAN YOUR FILTHY BIKE.

mstateglfr 

Did you clean the threads? Some wd40 and a toothbrush, wipe it down, then apply grease to the shell and bb threads.
That helps with install and removal.

It doesn't look really bad to me from the pics, but threadijg can be finicky.

speedyspaghetti

Lol I was actually planning on doing that today but then I realized I left my bike cleaner in my apartment (my bike stand is at my parents' house) and so I couldn't clean it.

speedyspaghetti

Yeah I tried - I used some brake cleaner, shop rag, WD40, shop rag again, and the PPL-1 Grease on both sides. It threads in a bit and I can turn it with the supplied BB tool but then it gets really tight about 2 or 3 turns in and I feels like if I keep going I'll totally mess up the threads.

speedyspaghetti

Does this look problematic?

noodle soup

the hard part of the cleaning is already done. Now that you removed the crankset, clean it up before it goes to the shop

Yes, but nothing that can't be fixed.

speedyspaghetti

1. Yeah - I had planned on cleaning it since I was taking it apart anyway but this frustrated me and I gave up on cleaning it today. All the bike shops around here are friggin maxed out because all of a sudden everyone wants to ride so I have a week to give it a nice clean. Matte paint sucks though - at least for cleaning purposes.

2. Cool - hopefully the shop can do it well without any "surprise" fees. They said $45 to chase the threads and I only need one side.

shoota 

I just came to own an old Bianchi that was acting this way. And its threads looked way worse than yours. Went to install a BB and it was a no-go. But for some reason I decided to try a different BB, went right in. So basically what I did was use that BB that went in to clean up the threads, both in gunk removal and straightening. After that first BB went in easier.

sdmc530

If you can't get it threaded go to your LBS. I had this one time, I messed up the threads and couldn't get it started. My LBS had a tapping thread, ran it though once and it was good as new.

motorthings

Crazy idea here, but could you cut some slots into the old BB perpendicular to the threads to turn it into a kind of tap, then thread it back into the frame to chase the threads yourself.?
https://www.instructables.com/id/Mak...p-from-a-bolt/

JohnDThompson 

Yes, you can. You need to take care that the cup doesn't go crooked as you thread it in. A real piloted bottom bracket tap set ensures that both sides of the shell are tapped coaxially.

popeye

This works. It looks like one last thread is folded over. Get a magnifier, light and a pick if nothing else. You can do this.

speedyspaghetti

Thanks for the advice and help everyone - I was able to get it figured out. Unfortunately now I realized that the crankset I bought is not compatible with my frame... soo... yeah.