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How to service a Dura Ace 7700 Bottom Bracket

Version francaise

	First remove the chain, chainrings and clean the bike thoroughly. If you do this indoors put down a sheet to trap falling grease, it will make for greater marital harmony. Better still, do this outside or in a workshop.
	Up close you will see a retaining nut (hexagonal centre) with a dustcover that can be loosened with a pin spanner or a sharp nosed pair of pliers. You might be tempted to remove the dustcover and screw out the retaining nut.
	This is what you will see in that case. However this is not the correct manoeuvre, because now you can't remove the crank! The dustcover and retainer work together as a crank remover. Put them back where you found them, tighten both the retainer and the dustcover. Now undo the retainer using the hexagonal key. As the retainer unscrews it will force the crank off the axis of the bottom bracket
	Success!
	and this is what remains. Now do the same with the left crank.
	So far so good. Now to remove the lockrings holding the bottom bracket.
Tool for removing lockring. Note the extension tube on spanner for extra leverage	To remove the left hand lockring you will need a special tool, pictured at left. The right lockring also requires a special tool and it can be quite difficult to remove. ATTENTION: The right hand lockring on the DuraAce 7700 BB has a left hand thread!
	Here are all the pieces in order. The special adapter is at bottom right.
	Hmm, sorry for the focus! Looking inside the BB shell you can see the screw that holds the rear derailleur cable in place as it passes underneath. It is important to ensure that this doesn't protrude too far, so that it crushes the cover on the BB when it is in place. Clean out the shell and wipe all the parts of the BB clean with a rag.
	Now you are ready to reverse the process. Spread grease liberally on all parts of the BB mechanism. A diagram to aid the reassembly can be found here (courtesy of Shimano). For other models look on the "Coin technique" page.
	For interests sake here is what the Ultegra BB looks like (bottom). It is 20g heavier, but is a sealed and practically serviceless unit. It is actually better than the Dura Ace version.
	Reassemble the bottom bracket and screw it carefully back into place with the cover in place. Tighten the right hand lockring with the BB tool. Install the left hand lockring and tighten it with the same tool you used to extract it. It is a good idea to install the right hand crank at this stage for leverage. When the crank becomes difficult to move, the adjustment is too tight. Back off half a turn and you are done. There should be no play in the BB, if you are unable to adjust it so that there is no play and that it turns easily, you need to replace the BB. Now put on your best gear and go for a spin!