I live outside the USA bought a GT I drive without seeing it and now that I have been riding it and done some work on it realize that I need some place to get advice. I'm mechanically inclined 59 years old and have already located and installed a new rear cassette and chain. I also discovered that adjusting the front derailleur is very tricky. LOVE the bike but realized there may be some on going maintenance issues that I should know about. any advise is appreciated. I have some questions about the bottom bracket specs and a click that developed in the rear sprocket, thanks