Bicycle Mechanics - both side of my bb are reverse threaded?

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twiz
08-18-07, 02:07 PM
I just got back from the bike shop, where I attempted to install a bottom bracket in my new custom frame and the mechanics at the shop helping me said both sides of my bottom bracket are reverse threaded. I guess they don't make a bottom bracket for this?

He said It can be fixed if I have it switched to italian thread. Any suggestions? I just want to ride it.


CdCf
08-18-07, 02:39 PM
How about an Italian-threaded BB put in the wrong way, and an English-threaded adjustable cup on the other side? Both would be "backwards" (i.e. tighten the same direction as pedals) then, would they?

Wil Davis
08-18-07, 03:36 PM
I just got back from the bike shop, where I attempted to install a bottom bracket in my new custom frame and the mechanics at the shop helping me said both sides of my bottom bracket are reverse threaded. I guess they don't make a bottom bracket for this?

He said It can be fixed if I have it switched to italian thread. Any suggestions? I just want to ride it.

Do you mean that someone installed the BB backwards, or that they cut the threads incorrectly? The threads should be left-handed on the drive-side, and right-handed (regular) on the non-drive side. You might get away with installing Italian or French on the drive side (as both French and Italian are RH threaded on the drive side), but the non-drive side should be regular (RH) threaded, even if it's Italian or French.

If you have LH threads on the non-drive side, then you're out of luck if it's a regular fixed-cup on the drive-side, and adjustable cup on the non-drive side BB. However, if you're using cartridge bearings, then you might be able to find something which has LH thread for the non-drive side. Perhaps that's what your LBS was trying to say.

- Wil


HillRider
08-18-07, 05:01 PM
If the mechanic is correct you have a major issue with the custom frame builder because he really screwed (pun intended) up.

terry b
08-18-07, 07:41 PM
One of two things - either your LBS guy does not know what he is talking about or the person that built your frame did something really stupid.

Assuming it's the latter, I would get on the phone immediately and work it out. It would be completely foolish to try and jury rig some solution to a screw-up like this. You paid for a custom frame and it should be built properly. I had a similar experience with a custom in which they did not tap the BB deep enough for a standard Campy BB. It went back in the box to be repaired, shipping paid in both directions.

Deanster04
08-18-07, 11:25 PM
How about an Italian-threaded BB put in the wrong way, and an English-threaded adjustable cup on the other side? Both would be "backwards" (i.e. tighten the same direction as pedals) then, would they?
The size of the Italian and English BBs are quite different. Go back to the builder and find out what BB he tapped for. Check out Sheldon Brown's site for the exact answer.

twiz
08-19-07, 11:39 AM
Go back to the builder and find out what BB he tapped for.

He said he doesn't tap the shells and that the threads are part of the casting. I'm hoping the guy at the shop was wrong.

Dr.Deltron
08-19-07, 11:59 AM
As a "fix", you could use a Phil Wood bottom bracket and just get 2 left threaded mounting rings.

Just a thought, now matter who "screwed" up. ;)

well biked
08-19-07, 12:14 PM
He said he doesn't tap the shells and that the threads are part of the casting.

It sounds like you've already talked to the framebuilder, and he gave you this info in response to your telling him the bb shell may be threaded wrong. News flash to custom frame builder: if it does turn out that the bb shell is threaded wrong, it's a DEFECT, and you built the frame with a defective part. Good grief.

If the framebuilder has a problem with whoever supplied him with the bb shell, he should take it up with THEM. As for you, he owes you a frame with a properly threaded bottom bracket shell.

And I sure wouldn't settle for Italian threading in your custom frame. There's a reason even Italian-made frames use English threaded bb's these days-

mr.tool
08-20-07, 06:35 AM
this is what happens when young people smoke too much pot.

Lambo
08-20-07, 07:33 AM
this is what happens when young people smoke too much pot.

Yeah, they act like old people.