INSTALLING THE BOTTOM BRACKET

Installing the bottom bracket assembly is pretty much a reversal of removing it.  Start with the drive side bearing cup.  The bearings will already be installed in the cup. Smear a light coating of grease on the cup and bottom bracket threads and thread the cup into place.  Screw it all the way into the cavity.  Temporarily fit the non-drive side cup into place and install the Big Bolt in preparation for tightening up the drive side cup.  Clamp the 12" wrench in place with the Big Bolt and tighten up the drive side cup as much as you can.

Remove the temporarily installed non-drive side cup and install the plastic sleeve if one is present.  Cover the entire spindle with a light coating of grease and slip it into place.  With the bearings already installed in the non-drive side cup, screw it into place.  Continue screwing it into place until a slight drag is felt when you try to rotate the spindle.  The slight drag indicates that the non-drive side cup has been screwed in far enough to take out all bearing clearance.

Install the non-drive cup lock nut loosely and prepare to tighten up the assembly.  Now is the time to be very careful.  The non-drive side cup must be set so as to ensure that almost all play between bearings and bearing races has been removed.  You will have to feel for just the right amount of bearing clearance and it is difficult to tell someone how to feel for the proper setting.

Snug the adjustable cup (non-drive side) up until the spindle drags slightly on the bearings.  Now back the non-drive bearing cup back a very tiny bit (1/8 turn might be close to just right to begin).  Start with just the slightest bit of slop in the spindle.  You should be able to feel a wee bit of up and down movement and you should have to pay really close attention to feeling for the movement.  If it is easy to tell the movement is there, you have too much bearing clearance.

Thread the lock ring onto the adjustable cup until.  Snug the lock ring up until it is finger tight.  You must try to hold the non-drive side cup in this position as you tighten up the lock nut.  The adjustable cup will want to tighten up as you tighten the lock nut and you are trying to prevent this from happening.  Once the lock nut is tight, rotate the spindle.  Rotate the spindle.  If you can feel it dragging on the bearings, loosen off the lock nut and set the non-drive side cup again.  Tighten the lock nut and check for rotation again.  You are trying to set the position so that there is no drag and no slop in the assembly.  And it might take several tries to get it just right.  I rarely get this set perfect with a single try.

A word of caution!  It is better to leave a tiny bit of play rather than to have even the slightest amount of drag.  Any drag means that the bearings are too tight and wear will be very rapid.  I always set my bottom brackets up with the slightest bit of play to ensure that things are not too tight.  I also check my bottom brackets for good adjustment frequently during the riding season.

With the bottom bracket installed, clean off the exposed ends of the spindle in preparation for installation of the cranks.  And once you have the cranks installed, give them bit of a wiggle.  Can you feel any play in bottom bracket?  Chances are you will be able to feel some play.  If the play is excessive, you will have to attempt to adjust the bottom bracket bearing clearance again.  Keep at this until there is no drag and barely perceptible play.