Originally Posted by
Ghrumpy
A taper fit is a type of press fit, which depend primarily on friction to hold. There is some material deformation too but the friction of a press fit is doing the work.
Not at all. Torque is not transferred through friction. If it were a round interface, then I might agree with the friction argument.
Originally Posted by
Ghrumpy
I'm not saying fretting doesn't happen, nor am I saying fretting is OK. I'm saying the risk of damage from fretting is relatively less significant than the risk of other types of damage that a dry taper helps mitigate.
Sure, grease does reduce friction. No argument there. Whether that's a good thing or not is the question, isn't it?
Won't explain the same thing for the 10th time.
Originally Posted by
Ghrumpy
Yes, there is some elastic deformation of course, but it's manageable; that's what torque values are for, for both the fastener and the taper fit. It's the plastic kind I'm concerned about, which reducing friction increases the risk of by requiring different (lower) torque values that are usually not followed if they are even known.
How does lubricating reduce the material strength to make plastic deformation easier? In fact, dry mounting increases the likeliness of fretting during the installation process itself.
Originally Posted by
Ghrumpy
Glad that is settled, at least!
That's what we bicyclists do, isn't it? We almost always end up back where we started.
That would be a handy solution, but this is hardly Campagnolo's fault. Pedals have been made that way since forever, so everyone who's ever made a pedal has failed to do this. Probably because it's not such a big deal if you don't overtighten them. (Not to start on another topic, but pedal overtightening is another pet peeve of mine.)
Yes, not much of a big deal for most cyclists. But the argument was aimed towards using knowledge and experience to improve design and correct imperfections. It's not (always) done, not even by Campagnolo.