Bkrdr

hi I have a 1996 trek 730 (almost all still stock-tires) that I still ride often but as you can imagine from time to time needs repairs. Is there a forum specifically for multitrack folks as I always seem to have questions when replacing parts, for example what length/gauge cable do I need for the gear shifters and brakes, what length brake shoe/pad.stud smooth or threaded? soon i think will need to replace rear cog, when ordering what are the specs on that? bb shell width / length? with all the lbs swamped its diy for now. anyhow thanks -newbie to this forum