I have a Shimano LX hub that I put on my mtb about 5 years ago and then pretty much quit riding it. I have maybe put 50 miles on it since then, most of it around town, a few trails, and very little mud/wet. Now I want to get back to it, should I open it up and repack it? Sheldon Brown's site seems to suggest that I may not. Looking for some expert advice. Thanks.