I am getting my Downtube ready for use on a boat in a salt water environment. I am changing out all the
lines and housings for stainless wire and housings with better sealing. Is the bottom bracket sealed or can I add grease there? Should I be adding grease to the headset and is there anything to be done with the shocks etc?
All exposed parts like brake handles and derailleur will be getting plenty of Boeshield sprayed on
(a waxy version of WD 40 allowing the oil to stay put better).
My big question is really about adding grease to hubs and BB. I will be putting on an expensive
Shimano Nexus 8 speed hub and I want it to last.
I don't know if you want to take the time BUT...anything you can polish will corrode less. I am totally serious. I used to manage a marina in an abusive salt water environment and I polished the heck out things to help keep corrision at bay and then used products like Boeshield AND LPS (various versions) to keep things in top shape. WD-40 is best used as cologne in a marine environment or for starting fluid but it stinks for really inhibiting corrision from salt water spray.
As long as you have the correct BB extractor, it's 30 minute job, max, to lube or replace a BB. 1) crank off, 2) BB out, 3) lube or replace BB, 4) BB in, 5) crank on. I bet Sheldon has a page on it. The touchy part is tightening the BB, but if you've axle bearings, you can do a BB.
I'd agree that if you have the right tools, it's a fairly straightforward job. I'm not an expert (just returning to biking and bike maintenance after a long hiatus), but I would think that if you are very concerned with protecting the bike from the elements and the expense isn't too much, you might want to switch to a cartridge BB. There's a discussion of the pros and cons here: