Originally Posted by
Slaninar
Fretting damage can happen either way, but dry mounting makes it worse, with some (more) damage happening during the mounting process if mounted dry. Not putting much torque on the cranks does help as well. Heavy, strong rider that prefers mashing is more likely to suffer from improperly mounted cranks.
What holds a taper fit on? Friction. What causes fretting? Repeated relative motion. Grease effectively eliminates the former. If a crank is properly pressed onto the taper, you should not get any of the latter.
By the way, the bolt does not hold the crank on. It presses it on, but after that it serves to keep it from coming off. How? By preventing repeated relative motion.
This is easily verified experimentally.
Originally Posted by
Slaninar
This is not true. Try it on some old BB. Lube, and try overtightening the crank. See if the bolts threads strip first, or the crank moves too high up/splits. Your claim that lubing helps the "overtightening" is simply misinformed IMO. Could I be wrong? Possibly, but I'm yet to find theoretical, or practical evidence against lubing and/or towards dry mounting.
Either you're not reading what I wrote, or I wrote it badly. Let me try again.
I claim that lubing tapers more easily enables overtightening of the crank (among other things.) Repeated overtightening eventually causes deformation of the taper hole in the crank. Repeated deformation eventually causes the crank to either bottom out on the cup, the bolt to bottom out on the spindle, or the crank to crack.
IMPE, the most common of these by far is for the bolt to bottom on the spindle. The other two are relatively rare. But I have seen both.
I am NOT claiming that lubing the tapers lets you overtighten the crank to failure in one go. You keep arguing against something I never wrote.
Originally Posted by
Slaninar
Doing something for long is not enough all by itself for one to become good at it.
Again, you said it, not me.
Originally Posted by
Slaninar
Learning and experimenting, in addition to practise is what does it. Don't know why they wrote such instructions. But they make no sense.
Campagnolo didn't just make cranks and ship them off and never think about them again. They have for 60 years provided racers and racing teams with them, and also race support. They have experience with their products from production to the end of their service life. They've seen the mistakes and the failures along with the successes. They have big numbers.
If their instructions don't make sense to you, the problem might not be with the instructions.
Originally Posted by
Slaninar
I don't think I'm the one being "religious". Religious would be holding a written book as gospel, without questioning it. I've tried various methods, read various opinions and books and came to some conclusions. Still being open to corrections. However, like I've said, so far I'm with the "lube first" method.
That's one way of being religious. Another way is to refuse to understand things that don't confirm your point of view.
You just quoted me saying basically, "if it's done with wisdom and experience, it probably doesn't matter whether you grease or not." What about that idea sounds religious to you? Again, I'm not sure you're actually reading what I wrote.
I'm happy to continue this, but only if you read, and respond to, and argue against, things I am actually writing. Thanks for the fun.