Bicycle Mechanics - installing Dura-Ace 7800 Bottom Bracket

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OCRider2000
07-31-08, 04:44 PM
Got a few questions:

1. Should I put loctite anti-seize or grease on the two adapter threads?
2. Manual says I should tighten with my FC32 tool to 305-435 pounds. Do I need to get some sort of torque wrench adapter and somehow attach it to my FC32 tool? or can I tighten without the aid of a torque wrench?

3. Grease or anti seize on the two crank arm bolts?

Thanks

joejack951
07-31-08, 08:02 PM
1. I would think that the bearing cups would have some sort of locking compound preapplied. If yours do, I wouldn't apply anything else. If not, I'd use grease or antisieze unless they creaked and only then try Loctite.

2. With a wrench style tool like the FC32, the best you can do is guess at the torque by hand. Figure out the distance from the centerline of the bearing cup cutout to where you'll be applying the force and then divide the torque spec by that number (the torque spec should be in in. lbs. so measure in inches). That will give you the force you need to apply at that distance to achieve the proper torque.

Just FYI, assuming you gave the correct numbers, the torque will be 305-435 in. * lbs. (25-36 ft. lbs.). Torque is always expressed as a distance times a force (or vice versa). Think of what you are doing when you apply a torque with a wrench and it'll make sense. Say you have an 8 inch distance from the centerline of the bearing cup to where you are applying the force. You'd need to apply 38-54 lbs. of force to the wrench.

3. Either should be fine.
OCRider2000
08-01-08, 08:00 AM
1. I would think that the bearing cups would have some sort of locking compound preapplied. If yours do, I wouldn't apply anything else. If not, I'd use grease or antisieze unless they creaked and only then try Loctite.

2. With a wrench style tool like the FC32, the best you can do is guess at the torque by hand. Figure out the distance from the centerline of the bearing cup cutout to where you'll be applying the force and then divide the torque spec by that number (the torque spec should be in in. lbs. so measure in inches). That will give you the force you need to apply at that distance to achieve the proper torque.

Just FYI, assuming you gave the correct numbers, the torque will be 305-435 in. * lbs. (25-36 ft. lbs.). Torque is always expressed as a distance times a force (or vice versa). Think of what you are doing when you apply a torque with a wrench and it'll make sense. Say you have an 8 inch distance from the centerline of the bearing cup to where you are applying the force. You'd need to apply 38-54 lbs. of force to the wrench.

3. Either should be fine.

Cool, thanks.