Indy452

I want to verify that the bottom bracket chain side bearing cup threads are clockwise to loosen? My Cannondale criterium aluminum frame bike's cup is stuck and I don't know what to try to get it off. My crescent wrench opens a full 1.5" so it will fit but always slips off...Any other methods I can try to get it off? I want to service the bearings in there...


The white dots are my way of being sure I get the right side put back on where it was.

Andrew R Stewart 

The RH cup will have LH threads, so loosen in a clockwise rotation. Two tips for grabbing it with a wrench. First remove the LH side (that has a RH thread and is the "adjustable" side with the lock ring) then run a length of all thread or an old nutted rear axle through the shell. With big washers clamp the wrench to the RH cup. This way the wrench won't tend to slip off as easily. Second is to use a wrench that doesn't have a movable jaw. Less wrench opening movement will grip the cup better. Some people have used a bench vice to hold the cup and turn the frame. Expect the cup to be real tight. Watch how you position everything including yourself. It's easy to punch the bike or things when the wrench slips... Andy.

Wilfred Laurier

i am with ars above

use bolts and washers to fashion a device for holding your wrench on the flats

once you know you have it on securely you can put some sort of cheater bar on the wrench

once it loosens a tiny bit you can remove all extra devices and unscrew with just the wrench

be sure to use plenty of grease on threads of both cup and frame when reinstalling

Ronno6

Using a bolt/allthread and large washers can be tricky if your adjustable wrench has tapered jaws.
Get (buy, borrow, etc.) a wrench specific to the task, such as:
https://www.amazon.com/Park-Tool-HCW-...bracket+wrench
Then clamp it to the fixed cup using a bolt/allthread w/large diameter washers. That will prevent the tool from slipping off the cup.
A cheater bar or gentle persuasion with a mallet should do the trick.

jolly_ross

+1 for Ronno6. Exactly right I think.

rydabent

Andrew +1 Try everything he said. You might add putting some oil or solvent in from the open side.

cny-bikeman

When in doubt go to Sheldon's site or just Google what you need and add Sheldon. https://sheldonbrown.com/tooltips/bbcups.html