If you have seen assembly instructions by a crank or bottom bracket manufacturer please link. I think I have seen in previous threads regarding this that Campagnolo instructions say to assemble dry.


Phil Wood in the bottom bracket installation instructions says to oil the spindle and the crank. In the FAQs it says to use grease as their spindles have been designed for using grease. https://philwood.com/support/faqs.php


"We recommend that a light film of grease be applied to the taper. This is only a recommendation for Phil Wood bottom brackets, as our taper was designed with grease in mind."


This is a revelation that spindles can be designed for lubed install. It would be interesting to ask Phil what design feature causes them to specify grease, and how it would differ if they wanted a dry install.


Please link assembly instructions from other manufacturers if you've seen them.