I've been trying to do some XC with my stock $200 dollar Krave Banned bike. GOing up a mountain always drains the juice out of me, is it like that with all people? My fork has around 40mm travel and is super heavy, running on mechanical disc breaks, altus shimano rear gear changer, shimano SIS front deraileur and as far as I can see, the hubs have no name on them. What is the first priority I should upgrade? And what does it mean when someone has "broke" their rebound on their forks? Should I buy 2nd hand upgrades or should I save up for 1st hand gear? And if I were to buy 2nd hand gear, how do I test if the stuff works or not?