drilling out a bottom bracket

[bianchi1]

anyone done this succesfully?

This one has finaly beaten me. tried all the normal things. heat, wd40, long spanners etc ( and i was tunring it the right way!!) but the teeth have all been stripped of the bb, resulting in the tool just spinning with no grip.

its a english thread campag chorus

any advice!!!

 

[accountantpete]

No -my Chorus BB defeated me and I ended up giving the frame away. You have to drill through the bearings to get the axle out and then hacksaw the shell.

Good Luck!

 

[vernon]

A suggestion that I've seen is to use a nut and bolt threaded through the bearing cup and tightened, even spot welded to the bearing cup then a big spanner used to remove the cup.

Thankfully not had to go there myself.

 

[fossyant]

Use Coppa slip first ??????????

LBS job, but expect to pay........... not a home job, you'll wreck a good frame.

Had a BB stuck in an old 531c frame once, but used the opportunity to upgrade to a new frame...653.... ahem........ .....

 

[bianchi1]

its not a hugely valuable frame, just been a great friend over the last few years. We have seen many miles!!

Was going to upgrade soon anyway but still want to get this one road worthy again.

Off to the bike shop tommorow!

 

[PapaZita]

It may depend on the frame and BB materials. I had a cartridge type BB stuck in a decent steel frame. The cartridge and bearing parts of the BB were steel, but the threaded/splined parts were aluminium and plastic which I figured would probably fail before the frame did. I'd already had a go with a drill which may have weakened the splined rings, but nothing was moving.

I supported the frame very carefully and hit the end of the spindle as hard as I could with a sledgehammer. The cartridge popped out and flew across the garden, and I was able to roll up and remove the threaded bits fairly easily.

It was a bit of a last resort effort that could easily have ended in disaster, but on this occasion was a complete success. A similar result could probably have been achieved more safely with some sort of press, had I had one handy.

PZ.

 

[porteous]

Sheldon Brown

I have used the threaded rod/nuts/washers technique mentioned by vernon on 50 year old frames, it works a treat. I think you'll find a full description on the Sheldon Brown pages.

 

[Crankarm]

Turn frame on side and use Plusgas penetrating fluid on the edge of the cup which hopefully over a few days / a week will penetrate deeper into the threads. Then as suggested whack the end of the axle with a couple of sharp blows from a sledge hammer you could also do this on the outside of the BB shell itself but be careful not to damage it. The shock of the blows can free the cartridge and shell threads where they have seized. But be sure to make sure the frame is properly supported and won't become bent because of the sharp blows. Then undo cups. Use a large adjustable wrench or socket and bar. Remember one cup is reverse thread and I'm not telling you which one! Make sure the BB cups are clean before you put the tool in as you don't want it slipping and chewing the metal up. When you try to turn the cups make sure all your weight is on the tool so it cannot twist or turn and slip off but you must support the frame with wooden blocks, card and towels to protect it from damage or bending.

If this fails take to LBS. If they can't get it out without knackering the frame then write it off. No point throwing good money after bad.

 

[Manonabike]

I had BB that I just could not remove with the nut and bolt trick. In the end I decided to get my car mechanic to have a go - I thought he could weld a nut to the cup but before he did that I remember a trick mentioned by Sheldon Brown.... using a vice. That worked very well but you need a really good vice to grab the cup and rotate the frame.

Just wondering, do people use grease when they fit a new BB. I put lot of grease before I installed the new BB and I hope it works cause I don't want to go through the same thing again :-)

 

[woohoo]

I use Coppa slip rather than "ordinary" grease on the threads. It has worked fine when I've changed the BBs (when I fitted a triple for a very hilly trip).

 

[Crankarm]

I had BB that I just could not remove with the nut and bolt trick. In the end I decided to get my car mechanic to have a go - I thought he could weld a nut to the cup but before he did that I remember a trick mentioned by Sheldon Brown.... using a vice. That worked very well but you need a really good vice to grab the cup and rotate the frame.

Just wondering, do people use grease when they fit a new BB. I put lot of grease before I installed the new BB and I hope it works cause I don't want to go through the same thing again :-)

Yes. Also when doing a full service on your bike you should anyway periodically remove all fittings, bolts, nuts, etc, clean and regrease so that when you need to actually replace items they haven't seized in place. Common sense really. Unfortunately in the factories in China and Taiwan bikes are built "dry" no grease IME.

 

[Manonabike]

I thought that Coppa slip and aluminium don't go well together and the BB cartridge is made of aluminium (I think )

 

[Manonabike]

Yes. Also when doing a full service on your bike you should anyway periodically remove all fittings, bolts, nuts, etc, clean and regrease so that when you need to actually replace items they haven't seized in place. Common sense really. Unfortunately in the factories in China and Taiwan bikes are built "dry" no grease IME.

Quite agree with that. I thought I would do something like that but not only with the BB, regrease the pedals and seatpost too.

 

[Crankarm]

Quite agree with that. I thought I would do something like that but not only with the BB, regrease the pedals and seatpost too.

Yes, periodically everything. In fact decent bike shops use anti-seize grease which is typically white on pedal threads, seat posts and BB threads. I only use copper slip on steel. I am reluctant to use it on ali as not sure that there might not be electrolytic action causing seizing. Maybe worrying about nothing but prefer to use LM grease or Finish Line bearing grease with Teflon.

 

[bianchi1]

the trouble is that the 'teeth' on the bb have all sheared off so no matter how much slip stuff i put into the thread the tool just spins in the remaining hole.

have decided on a hacksaw method. Fingers crossed!!

( the good news is the new bike is ordered and on its way )