Creaking BB Problem

[Paulson]

Hi all, my RST has a problem that is currently irritating me intensely, and which I can't seem to fix.  I have a persistent clicking/creaking from the BB area when I pedal - primarily when the left crank / pedal is pushed down.  Normally, this is the sign of one or both of the EBB grub screws coming loose. 

However, I have so far:

1) Disassembled the entire BB area

2) replaced the EBB shell with a new one

3) Replaced one of the M8 screws with a new one (one sheared off due to overtightening some time ago)

4) Taken out, greased and replaced the bottom bracket itself

5) Re fitted the entire assembly, torquing the M8 screws to approx 15nm (Thorn says 10-17 nm), and the cranks to 40nm, and the BB to 55nm (drive side) and 10nm (non drive side) as recommended by Thorn.

And yet it still creaks.  It is driving me mad - the only thing I have left to try is replacing the actual BB itself (some 4 years old but fewish miles) with a new one.

I observe that, when the adjustable EBB shell sits inside the BB bit of the frame, you can see a very small gap between them at the area where the screws are situated.  I guess less than a millimetre. This infers to me that the frame part of the BB inside which the EBB shell fits is of a very slightly larger diameter than the actual ebb shell unit itself - meaning there is a small gap between the shell unit and the frame, thus allowing a small amount of movement of the shell unit?

So, is it usual for the EBB shell unit, when tightened into place by the 2 screws, to show a very small but visible gap between itself and the frame [where the screws go in], or should there be no visible gap?

My only theory is that because of the 'play' or gap between the frame's shell housing and the shell itself it is allowing the shell unit to move slightly under torque and thus causing the creak?  However if this is normal to all ebb equipped Thorns I may be barking up the wrong tree.

Any ideas? Thanks.

**BTW, I have read the other recent post - http://www.thorncycles.co.uk/forums/index.php?topic=2540.0 - and tried the chainset bolts....

[rualexander]

Noise might be coming from pedals?

[Paulson]

Ok, now removed chainset bolts, re greased and reassembled; also removed both pedals and regreased/tightened.

Noted that pedals, while not loose, weren't that tight.  Also, on non drive side crank, quite a lot of 'wear' in the alloy around the threaded hole for the pedal spindle....

Will report tomorrow, after breakfast!!!

[edit 17/8/10] - SORTED!  Late night chainset strip down, grease and reassembly, then pedal strip, grease and reassembly has resulted in a bike where the only creaking now comes from the Brooks saddle!  The problem seems to have been an unlubricated, and maybe slightly loose pedal.  Wonderful, and thanks for the advice Ru!

[Blacksail]

I have had the same creaking noise, again only on the left hand side, for a couple of days. I tried an old pedal but the noise continued and just to be sure I rode the bike without a pedal, just putting pressure on the crank, the creak persisted.

My cure, and it doesn't make any sense to me, was to take up the slack in the chain, which was minimal, using the EBB. Problem solved....

Worth noting I am running a 10,000km old chain and had to remove a link as I'd got close to 90 degree of turn on the EBB ( I mark each tightening of the EBB with a white dot so I can aim for the same indents next time round)