In this video I’m looking at “custom tuned” rear shocks that people are selling on Facebook Marketplace, and why this matters way more than most riders think. A custom tune can be awesome, but only if it’s built for the rider, the frame leverage curve, and the terrain. When you buy someone else’s tune, you’re basically inheriting their problems—or their perfect setup that won’t match you. I’m not here to copy charts or repeat marketing; I’m trying to show what actually matters when you’re deciding if a used tuned shock is a score or a headache. I break it down by common scenarios: an Avalanche-tuned shock, a Fox-tuned shock, and a DVO-tuned shock. The big takeaway is that “tuned” doesn’t automatically mean “better”—it means “specific.” I talk through what I’m looking for, what questions you should ask the seller, and what red flags make me walk away. If you want a tune that actually works for you, I also point you to my quick guide that helps you tell a tuner exactly what to build so you stop guessing and stop wasting money.