I’m a a nice guy but that doesn’t buy dinner.
I have an opinion on this topic! I know that it's difficult and overwhelming to run a small business, especially a bike shop. You've got forecasting and ordering, lots of expensive inventory to potentially mark down before it gets outdated, insurance against fires and theft, and the rent for a physical location that has decent parking, as well as employing sales people AND technical mechanic type people. It's a big job... This is why I enjoy visiting shops, calling them out in my videos, and promoting them with the dealer map tool thing.
Anyway, from what I've observed, the challenge of servicing bikes seems best met by charging a lot of money for the work. This pays for your mechanic, cuts down on volume, and can create an incentive to buy new or seek other service providers. You can say things like "we have a $20 assessment fee and you need to bring your bike in, we cannot answer questions over the phone and we are unable to get some parts for bikes that we do not sell". It's easy to offer discounts or favors, but difficult to request more money, so the small up front fee and "in person" requirement to do work will save you time and share the "cost" of repair with the customer by requiring their time and energy as well as a nominal fee for your appraisal. You can charge $50+ per hour of labor plus parts... and if a customer feels that your $200+ derailleur repair and full bike clean plus service is too expensive, they can be the one to feel upset instead of you for being "too nice" and giving your time away and then feeling resentful. I just spent $800 having my Uncle's Haibike fully serviced, new tires, new grips, and Bosch motor tunup. I also spent $500 having my full suspension non-electric bike tuned up ($90 for the clean and tune + $400 for hydraulic brakes and suspension rebuild including parts). Two different shops were used, and I was happy to pay and they were very polite to me. We both win.
Charge the amount of money that will make you happy to spend your time and energy, let the customer choose whether it is worth their money and time to agree. I don't know your specific situation, but I have seen way too many shop owners who want to be appreciated, but aren't charging enough for their time and then get hurt feelings when some customers (who are often struggling) take too much or ask for unreasonable things. This is your opportunity to solve the problem by creating boundaries for yourself. Boundaries are healthy! This is why I am not able to review every ebike, reply to every comment, or do a perfect job with my own work. Good luck
@tomjasz and know that you're not the only one feeling monetary inflation, environmental overload, pandemic stress, and overpopulation. Make space for yourself, then continue being nice within that space. Let go of trying to do everything for everyone.