Ballbearing is the heart of the yoyo. It makes it spin a long time and thanks to that you have a lot of time to make tricks. It’s also the part which requires most maintenance and care. If you have a dirty bearing you can forget long spin times or smooth spining yoyo. Bearings differ in size and types and they also determine the fact if the yoyo is responsive or not.

Bearing sizes

There are three basic bearing sizes in modern yoyos. A, C and D. Generally you can claim that small (A) sized bearings spin faster, large (C) sized can take more strings in the gap and medium (D) sized are the combination of both.

Bearing Measurements yoyo companies using this size
size A (small) 5mm x 10mm x 4mm Duncan, YoyoFactory
size C (large) 6.35mm x 12.7mm x 4.52mm most metal yoyos, Duncan, YoyoFactory, C3, CLYW…
size D (medium) 5mm x 11mm x 5mm SPYY, hSpin

After years of yoyo development the manufactuers finaly understood that all the different sizes need to be standardized and we’re in a point where we have just three basic bearing sizes. That opened the floodgates for wide variety of different bearing types. You can really improve your yoyos performance by upgrading a bearing but beware that bearings can wear out, even if you treat them properly. Good thing they’re replaceable, right?

Bearing types

Type Shape Properties
FLAT (SPEC) Standard ball bearing included with a vast majority of begginer yoyos and other affordable products. FLAT ballbearings differ in quality (some are not even made from stainless steel) and you can find amazing ones as well as crappy ones. The price rule (more expensive = better) generally applies to these. Yoyofactory has it’s own name for a FLAT bearing, they call it the “SPEC” and you can distinguish it by a “YYF” engraving on it.
Concave bearing (KK) This is an invention of a US based company Dif-e-Yo and it’s owner Frank. It’s possibly the first alternative ball bearing type/shape we ever got. The difference is that it’s profile is not flat but made into a U shape. This has a number of advantages, primary one being that the string stays in the centre of the yoyo, that reduces friction and allows the yoyo to spin longer. You can also fit more strings into the string gap because they can layer up more easily. One can say that the yoyo spins longer and performs better for advanced tricks but it’s going to be difficult for a beginner to return a yoyo with this type of bearing in it. Frank Difeyo is a clever person and he patented his invention (only in the USA though) so you can either get the original Dif-e-Yo bearing which is superior in quality or a Chinese, knock-off one which can be as good (for a fraction of the cost) or not good at all. If a yoyo company want’s to sell a concave shaped bearing (yoyo) in the US it has to have a patent agreement with Frank. Many yoyos sold outside of the US have a U shaped bearing but they’re replaced with FLAT ones for the US market.
CenterTrack YoyoFactory doesn’t really like to pay use other company inventions so they cleverly avodided a patent infrigment by adjusting the shape of the concave bearing. They call their bearing “CenterTrack” and the primary difference is that the U shape now has two slopes / steps on either side of the profile. Most people have a love or hate relationship with this bearing but they all agree on one thing – it’s the loudest bearing out there.
Gold(plated) bearings Bearings plated or made from gold are a part of the market for some while now and some of them stand out more than others. Most popular ones are golden CenterTrack and golden bearing from Japanese yoyo shop called SpinGear. These perform better than the standard, stainless steel ones but there’s a larger number of b-grade items which is annoying if you consider their price.
Tenball Ballbearings which use 10 balls instead of the more usuall 8. These are much smoother and a bit quieter than 8balls. Some of them take some time until they perform at their best, first you have to wear them in.
Ceramic, Grooved, Trifecta, Dorothy, Terapin… There’s a massive number of alternative bearings on the market today. They can be made from ceramics, have ceramic balls, have grooves in them, have different shaped slopes and other amazing concepts. You can even buy a dry, dust like lubricant for your bearing. Some of these are just snake oil, some of them work superior to others. We shouldn’t really be saying this but … just practice a bit more, it’ll make up for it.

Responsive or unresponsive (tug or bind)?

Almost every bearing (yoyo) can be adjusted for responsive or unresponsive play. If you throw the yoyo into a sleeper and it comes back after a tug you have a responsive yoyo. If you throw a sleeper, tug and nothing happens and the yoyo just keeps spinning you have a unresponsive yoyo. The (major) difference is if you have your yoyo lubed or clean/dry.

Begginers should always start out with a yoyo which is responsive out of the box!