brussel Posted October 20, 2009 Posted October 20, 2009 OK so I have a retro tomassini that has a POS fag BB in it. It is made of plain aluminium - not alloy - plain soft as soap aluminium. using a proper BB tool with even moderate leverage totally rips the alu to pieces. it is stuck and it is now in pieces in the bike: the outer ring on the one side will not budge and in the process of hitting it with a screwdriver and a hammer it disintegrated. the other side will not budge even with two 5mm holes and some serious leverage on some high tensile bolts. help? my current idea is to cut with a hacksaw transversely (parallel to the BB axle) into the steel thread on the BB and then 'peel' it out.brussel2009-10-20 13:13:35
Mecnic Posted October 20, 2009 Posted October 20, 2009 Sounds like the Alluminium may have rusted, yes aluminium does oxides and in effect the turning force has almost cold welded it to the frame, I would try soaking the entire bb in a bucket of oil/ applying penetrating oil to see if it loosens up a little. If that doesn't work carefully try to file opposing slits in the cups on the inside and crush the bb inwards be super careful not to cut into the frame if you do hurt the threads I'm shure a LBS can attempt to fix the threads with a bb threading toolGood luck
Johan Bornman Posted October 21, 2009 Posted October 21, 2009 Firstly you have to confirm that it is an Italian BB. Measure the bike BB shell width to confirm. 68mm for Anglais, 72 for Italian. That should now tell you which way to rotate out. Starting with the second photo first. Complete the drilling of the two holes directly opposite the spindle hole. Make yourself a pin spanner by drilling two holes in a piece of flat bar steel and inserting two strong pins of some sort into the bar. A press fit will be best. Mild steel may be too weak but try that first. Now wrench it out with that. If it proves too weak and even looks like it will damage the holes, stop. Modify the spanner so that it uses the centre hole as well. You may even way to clamp the pin spanner onto the BB shell using a G-clamp. It mustnt slip, you only have one or two chances. As for the other side in the first photo, it looks to me like you're halfway there. Or am I missing something.
Tankman Posted October 21, 2009 Posted October 21, 2009 johan, just out of interest, which way does the english thread rotate... left loose .... right tight? right?
Johan Bornman Posted October 21, 2009 Posted October 21, 2009 I have to confess that I can never remember. I always have to double-check on an old BB I keep nearby just for that. Nowadays they also paint useful little arrows on the BB. Italian is normal...roighty toighty. English has one screwed-up side.
Tankman Posted October 21, 2009 Posted October 21, 2009 so that is the left hand side on english that is screwed up (ther way round than normal)? same with some crankarms when installing pedals
brussel Posted October 21, 2009 Author Posted October 21, 2009 OK so I got it sorted...finally I tried everything to get it to rotate so finally i resorted to cutting it an peeling it and then with great pressure in the bench vice I managed to get it to turn out once I had destroyed the other side
Johan Bornman Posted October 21, 2009 Posted October 21, 2009 I've never seen one like that. It is quite weird with its full alu centre. Tip: resize your photos to 450 pixels wide, then we dont have to contortion-scroll to read the text.
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