I have a friend who got bit hard by the cycling bug this year, much to my surprise. I wholeheartedly support his new hobby/lifestyle change but he refuses to take any of my advice when it comes to spending money. I advised him not to buy a Walmart bike but he did so anyway and ended up realizing he made a mistake after trying a friend's real bike out. Now he has a better bike but won't let me help him with the most basic repairs. I offer to do it for him for free (because it's fun for me) and give him replacement parts from my collection but he insists on going to a bike shop for simple things. I won't pretend I never spent too much money at the bike shop in my more ignorant days, but I feel like I have come a long way in being a competent mechanic and resourceful at finding free or low cost replacement parts. I know there are plenty of honest bike shop employees who won't exploit people who don't know any better, but I also know people like him are the bread and butter of any bike shop and most will try to sell him something every step of the way. I don't want to start a debate on the value of local bike shops and the convenience/cost trade-off that most people are happy to live with, but one of the main reasons I enjoy cycling is that most people's repair needs can be met very cheaply outside of the retail establishment. How do I convince someone who doesn't know any better that he doesn't need to spend so much money on very simple repairs?