un71 confusion

[ellist]

I have got confused over my un 71 bb. It was poking out the drive side a so I decided to tighten the cup that side. The drive side tightened clockwise?. I undid the non drive side and a un71 dropped out. This must mean both the cups are loose. A bit wierd

 

[benbonty]

Both cups should tighten clockwise.

 

[JamesM]

The drive side should tighten anti-clockwise as its a left hand thread. Non-drive side clockwise to tighten as normal.

 

[jimo746]

On all the bikes I've had the DRIVE SIDE has tightened up ANTI-CLOCKWISE (ie lefty-tighty).

The NON-DRIVE-SIDE has tightened up CLOCKWISE (ie righty-tighty, aka the "normal" way).

you said you unscrewed the non-drive side and the bottom bracket popped out?
Usually with the Shimano sealed bottom brackets the main body is screwed into the BB shell from the drive side, and the plastic or metal "sleeve" is screwed in from the non-drie side.

Maybe it had been installed incorrectly?

What frame is it in?

 

[ellist]

Its a 98 cindercone. I thought all drive side would tighten anti clock. Like pedals

 

[Mike Muz]

Should be a lefty , as everyone suggested , my '98 Kilauea was . Easy way to remember if you have a senior moment , the cups undo the way the cranks go around . Don't know what happens if you put bracket in wrong way around though , never tried it I'm afraid .
Mike

 

[ellist]

I think it needs to be left alone until the bb needs changing. Could be complicated to sort

 

[hamster]

There were some early Shimano cartridge BBs with the loose cup on the right, but I'd cannot remember if they were UN70 or 71.

If somebody didn't know this then the BB might have been screwed from the wrong side, cutting itself a thread across the bottom bracket as it went. Best to look at the frame bottom bracket threads to see if it's happened. Alternatively, some monkey might have used an Italian thread BB and forced it in the same way. Either way, I detect bodging.

 

[cce]

English thread BB cups always *unscrew* in the direction that you pedal - it's how i remember it, and it's how i teach it...

 

[retron]

Surly it should screw inwards in the direction you pedal so as not to work loose?