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-   -   Cross threaded BB.... (https://www.bikeforums.net/classic-vintage/626370-cross-threaded-bb.html)

RobE30 03-05-10 08:44 PM

Cross threaded BB....
 
Yeah the title says it.... While reinstalling my freshly greased BB I'm pretty sure I cross threaded it:twitchy::cry: So aside from wanting to scream, how screwed am I? I'm too depressed to search.... Thanks guys

Shp4man 03-05-10 08:49 PM

Are you sure it's the right BB? Is it an older French bike?

RobE30 03-05-10 08:54 PM

Its the same cup that I took off the bike. It's a Trek

Ex Pres 03-05-10 09:00 PM

Just have your LBS chase the threads. You'll be OK.

Shp4man 03-05-10 09:00 PM

Bike shops have a thread chaser/truer tool that may fix you up. LOL, beat me to it^^^

Bianchigirll 03-05-10 09:01 PM

clean everything up and look at the threads real good. unless you really forced this chances are good everything is OK. However if you live near a bikeshop it never hurts to have them chase the threads for you.

you do use the old trick of holding the cup up to the BB and turning it backwards until you hear/feel the tick from the ends of both threads. then start slowly turning the correct way. always seemed to work for me.

metabike 03-05-10 09:01 PM

If you haven't yet, remove the cup and see how badly the threads are buggered up, you just might be able to salvage it. If not, find yourself a well equipped shop or a frame builder who has the Park tool for the job - here's the article from their website: http://www.parktool.com/repair/readhowto.asp?id=97. Good luck and don't feel too bad, sooner or later, anyone who does anything is going to mess up.

abarth 03-05-10 09:17 PM

It happened to me on my lotus. It is ok, just take it to your local bike shop. They should be able to fix it.

RobE30 03-05-10 09:19 PM

I pulled the cup back out and the threads look fine, so Monday I'll take it to my LBS and have them chase the threads. I have a tap and die set, but nothing w/ reversed threads.... Glad to hear I didn't ruin my newest purchase. There will be pics posted when she is all back together. It's been quite a transformation and I can't wait to ride her. Thanks guys!

miamijim 03-05-10 11:52 PM

Skillfully try to tread it back in yourself. I recently had a BSA threaded bike with the cups threaded into the wrong side of the frame. Yep....left hand threaded cup in the right hand threaded side and the right hand threaded cup in the left hand threaded side. I removed them and threaded them into the propr side with no need for chasing the threads.

If you have patience you can catch the correct thread with the cup.

wrk101 03-06-10 09:16 AM

If you try to reinstall yourself, be sure to use a good antisieze compound and take your time.

norskagent 03-06-10 09:24 AM

velo orange has a BB that installs independent of the threads, if it comes to that.
http://www.velo-orange.com/grcruthbobr.html

OLDYELLR 03-06-10 03:15 PM

Screw the lock ring on to the cup si the threads just barely stick out and then use it to align the cup.

Chombi 03-06-10 03:30 PM

When I was a kid, I used to cross thread parts on all kinds of things I took apart in the house to my parent's frustration.........and just continue to wrench on it till it "straightens itself out"........ after which the part spins free and falls out on to my hands.....huh??? what happened to the threads that were there??........... :D:rolleyes:

Tip: always hand thread screwed on parts af far as they will go first before putting a tool on it and you will most likely avoid corss threading them.

Chombi

Oldpeddaller 03-07-10 04:10 PM


Originally Posted by Bianchigirll (Post 10487510)
clean everything up and look at the threads real good. unless you really forced this chances are good everything is OK. However if you live near a bikeshop it never hurts to have them chase the threads for you.

you do use the old trick of holding the cup up to the BB and turning it backwards until you hear/feel the tick from the ends of both threads. then start slowly turning the correct way. always seemed to work for me.

Bianchigirll, this only goes to prove that I'm never too old to learn something new! Thanks for sharing this tip, I've always just started the threads the 'right way' by hand and mostly it works just fine. Your way ensures that the threads are engaged every time before starting. I'll definitely be trying this on my two current builds and passing on your wisdom!


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