I’m glad you raised this topic.
The agreed upon terminology is “Bearing Post”. “Bearing Seat” is the ledge that the inner race of bearing sits on and you definitely don’t want to sand that. That might seem too pedantic but it’s an important distinction. Also, do we really accept that it’s normal to have to sand a new product that you just bought? If it needs sanding, shouldn’t that be done before it’s sold?
Speaking of bearing posts and the now very common tight bearing posts, I feel it’s important to discuss this situation because it is one of the biggest differences between what we do at One Drop and what happens with many or most Chinese made yoyos. Nothing is free, so there are reasons why Chinese made yoyos cost less and the result of one of these reasons is tight bearing posts.
So why is that many Chinese made yoyos have tight bearing posts? Why do companies sell bearing removal tools? The reason is that the tolerance to make the post the correct size is incredible small. In manufacturing, the tighter the tolerance the higher the cost so to save money Chinese made yoyos are made with a looser tolerance on the bearing post. This tolerance is aimed at ending up with a tight bearing post because the result out of the box is a smooth yoyo. If the bearing post is too loose then it’s possible the yoyo vibes. Various yoyo manufacturers have been trained by the customers that vibey yoyos are completely unacceptable so if you are going to get the size wrong (and they get it wrong most of the time) they feel it’s much better to have a tight post and a smooth yoyo out of the box. The problem with this is that as soon as you take the yoyo apart (and especially if you try to remove the bearing) you begin damaging the bearing post with ultimately leads to the yoyo being vibey anyway. So they aren’t built to last in this sense. If you examine the bearing post on one of these yoyos you can usually see a black ring at the base of the post or sometimes even raw aluminum. If you sand the post as suggested above, you are likely to make the yoyo less smooth as well because it’s impossible to do it evenly - essentially by sanding it, you are damaging it.
It is possible to get lucky and get a Chinese made yoyo with a correctly sized bearing post, but in our sampling the percent that are tight is very high. This is supported by the fact that these companies sell bearing removal tools and that it has almost become acceptable as normal and okay to have the tight bearing (as YoYoexpert Garrett says “nothing to worry about”). We are also seeing people tout yoyos in the BST that have never been taken apart as a good thing.
Having made tens of thousands of yoyos in our shop we know exactly how difficult it is to get the post size right. Everyone who has made a modern yoyo has struggled with this. You literally have to hold NASA/Aerospace level tolerances AND then get lucky that the anodizer doesn’t mess it up. It is very difficult and very expensive to do it right. We would love to sell yoyos with press fit bearings and we could do it at a much lower cost because the tolerance is so much bigger. But we believe that the bearing needs to be serviceable without ruining your yoyo and we will continue to work hard to make this option available to you.
We have also noticed that import centering bearings on most of these yoyos have a rough surface on the inside diameter (the part that comes into contact with the bearing post), and that the inner race diameter is often undersized (making it even tighter). If you look at it under magnification you can see it. If you look at a One Drop 10Ball under magnification the surface is perfectly smooth. This rough surface also damages the bearing post because it’s essentially like sand paper. Depending on the tolerance matching, it’s possible one of these bearings in a One Drop can also damage the post.
Thank you to yoyoexpert and to all who continue to support us so we can continue to provide this alternative option.