shimano square taper bottom bracket stripped thread

tubbs_214

so then ive ran into a bit of trouble,

my cassette chain and chainset are a bit past it so i decided it was time to have a change and a bit of a update, so after trawling ebay i ended up with a sora crankset and a hollowtech 2 bottom bracket, so i started to swoop everything over this afternoon took my pedals and old crankset arms off all good then i noticed that the part of the bottom bracket where you put the socket thingy (technical term that is) is made of plastic so as i tried to remove gently it would not budge so i checked i was turning the socket the correct way and i was so i put some more pressure on and this was when i manage to strip nearly all the plastic bits of the bottom bracket and most of the skin of my knuckles both sides now have no plastic bits and my bottom bracket still hasnt budged

so is this knackered now or is there still away of removing it

ive salvaged it for now by taking the chainrings off my new chainset and replaced my old worn out ones im happy with this but would rather be using the sora chainset and once the bottom bracket dies eventually i dunno what ill do

thanks for any help and sorry for my poor spelling and grammer

craker

The drive side is metal - presumably you can unscrew it from that side and remove the bottom bracket that way. You're left with the plastic cup on the non drive side... hacksaw it out, it's easy enough.

Remember that the drive side thread is left-hand - you unscrew it clockwise.

tubbs_214

nope both sides are shot and plastic how would i hacksaw it out

tubbs_214

http://www.sjscycles.co.uk/budget-seale ... -prod5001/


its got something similar to that im not in no rush to sort it as i can still use it just thought if there was a easy ish way that i could get it out id give it a go ill have a word with my lbs

thistle_

If it's plastic it shouldn't seize either so it should be quite easy to take out.

I've not come across an all plastic one. If it looks like the one in the picture, can you get a pair of mole grips on the flanged side to undo it from that side, then hacksaw the other cup out?

You might be able to get a pair of mole grips on the other side too if there's enough of it sticking out.

If it won't undo, try turning it the other way. If it moves a tiny bit in the other direction it might loosen it enough to let you undo it.

If you can get the main cartridge out, you can carefully cut two parallel lines across the plastic cup, lever the strip out you've just made then 'crush' the remainder of the cup so it is a smaller diameter and comes out of the frame.

As a last resort, melt it with a blowtorch and spend ages cleaning up the mess afterwards?
You should consider getting the threads retapped anyway if you are converting to Hollowtech 2 - you don't have to do it, but should consider whether or not you want to get it done.

slowbike

If you've stripped both sides then you should be able to push the BB out the drive side. The non-drive side is just a guide to hold it in the right place and doesn't (IME) grip on the BB at all.

As I doubt you've completely stripped it the best way may be to apply a moderate amount of pressure to push the BB out and undo the drive side out at the same time - the pressure whilst turning will help ease the whole lot out.

To apply pressure to the BB - use a clamp against the square drive - don't forget to use cloths and wood to protect the rest of the bike!