Ok, so I was playing with my Supernova, and I noticed it had a lot of vibe. I thought it was just my throw, since I haven’t hit the yoyo on the floor or ground yet. So I let the vibe issue pass, then I decided to change my string, and Voila! The yoyo was spinning completely smooth and vibe-free. Does this mean vibe could mean your string needs to be changed?
Sometimes that can be the case when your string’s tension is off a lot but usually it’s because of something else. Did you unscrew your Supernova to take off the string? If the yo-yo vibes a lot, tuning it can help get rid of the vibe as long as you do it right.
No, what I mean is that with a worn-out string, I had some vibe, but when i changed my string, it had no vibe. I unscrewed the yoyo once that day before the string replacement, due to a knot. Should I still tune my yoyo?
I’d say the change was caused by your unscrewing the yoyo and then putting it back together. That re-seated the bearing and changed the tension overall across the the axle. A worn string won’t affect it, there’s just no mechanism for that to happen.
Another thing, are you measuring vibe based on how the yoyo feels immediately after you throw it? Because if so, that is not how you decide if your yoyo vibes. You have to drag your finger lightly on the spinning yoyo’s edge for a second to cancel out issues with your throw. At this point, string is totally out of the equation since it’s only touching the bearing track.
Dang, I thought I discovered a new theory or something like that. >:( Then my yoyo has no vibe at all, once I put my finger on the edge. Thanks, guys! 
I’ll have to disagree here. I’ve noticed that my yoyos sometimes play much better with a new string. So yes, that can have an effect.
Mine had a vibe in for a while and I change string and it still had a vibe. even finger tested for vibe and it was supposedly my throw. Turned out I was afraid of stripping my yoyo so much I wasn’t tightening it enough. Something to consider. Oh and I went back to the old string and no vibe with proper tightening and when it did finally wear out it had a little bitty vibe but nothing like what did have.
Well, I found that with an old string, binds are looser and when you throw the yo-yo will vibe. On the contrary, new string allows tighter binds and the throw is more solid leading to less vibe. It recently happened with my Old legacy. String change then boom: less vibe
There’s no question your throws will play better with new string, the question (imo) is whether or not a string can cause vibe. I know it can’t because when you test for vibe by running your finger along the throw, you isolate the effects of both your throw and the string.
It could cause your throws to bit a little more vibey if the string is so worn that the response is slipping on the way down, but it doesn’t change anything about the yoyo itself. It’s still a consequence of your throw, which varies too much to attribute any one thing to the change in vibe.
When string’s worn, my yoyos tend to feel sloppy and just feel like they’re hanging on a wet noodle rather than having that little extra bounce when hitting the end of the string. Sloppy comes with slippy response, slippy throws, and vibe due to the poor throw. I do tend to use my string as much as possible until it begins feeling off and when the overall string looks faded (I tend to use the neon green).