Originally Posted by
Ghrumpy
Maybe I wasn't clear about what is being overtightened. I'm talking about the taper fit, not the bolt or nut. IOW, pushing the crank too far onto the taper.
This also won't happen. Don't take my word for it. If you have an old set, try doing it in one go. Lube it with any lube and try pushing it too far. Bolt will strip first.
The way to push the cranks too far is to put them on dry. They will get a bit (more) damage in the process. Then ride a bit, let the fretting do it's thing. Then re-tighten the bolts. And repeat that several times. Finally, the cranks will be pushed too far, resulting in a split crank interface if you go far enough.
You can do that even with lubed ones, of course. Just keep riding-re-tightening the bolts.
Originally Posted by
Ghrumpy
In this case, as I was implying before, it's not about right or wrong. It's about tradeoffs. When manufacturers and bicycle service institutes make recommendations, I think it's fair to say they've weighed the options and done their testing, engineering, and reverse-engineering, and don't make those recommendations because someone BITD told them that's how it's done. Their collective experience is considerable, and well earned.
Some recommend lubing. Some recommend dry mounting. Bike industry, IMO, is mostly about marketing, which mostly relies on looks and low mass (weight). Good engineers are in auto and aeroplane industry.
I have quite strong hands. Never have I been able to tighten the bolts so that the cranks are split in one go, or they "climb" too high. Lubed, or not. So, at least mine, experience confirms what I've said. Could it all be wrong? I guess it's possible. Only after 20 more years could I claim my experience to have any sort of statistically valid value - it's about big numbers. Also, if I find/hear an explanation explaining the "opposing" (dry mount) theory that holds water, I'd be happy I've learned something new and correct my views and practice.
Off topic: about 9 years old, overhauling an old lawnmower with my father. He told me to tighten some (rather large) bolts. I asked how tight? He said "as tight as you can". Considering the tool I'm using is not a long lever and I'm a kid, so he'd probably have to check and re-tighten the bolts. I had stripped the first one, realized it and let him know, before doing any more damage. He just laughed and couldn't believe. "I underestimated you, it's my fault". Afterwords he would always joke about it when we worked on something: "tighten with small force, you know, NOT stripping the bolts..."
@
gearbasher I have the manual in the shop. Was "delighted" with the instructions. That, and the right hand thread on the right side of bottom brackets are the jewels of Italian engineering IMO. Though I'm yet to test the infamous Campagnolo delta brakes.
Nothing against Campagnolo, really, love their brifters, love how they made the whole system shift nicely (Shimano got it right in 2nd go with 10 speed, and with 11 speed road), and the design is lovely as well.