When a Duncan yoyo comes with a concave bearing, is it always a genuine Dif-e-o Konkave bearing?
Related question: what makes Dif-e-o concave bearings different/better than generic Chinese concave bearings?
3 Likes
The fact that they’re DIF-E-O
3 Likes
Care to elaborate?
1 Like
Duncan licenses the patent and specs from Frank Difeo to produce their Konkave bearings. They then either source the bearings from the same factory as Dif-e-yo (unlikely) or follow the specs at their own manufacturers to produce a similar bearing (more likely). So for all intents and purposes, a Duncan KK is as genuine as you can get to a Dif-e-yo KK without the “dif” stamp on the side of the bearing shield.
Not all Duncan KK bearings are created equal and my experience with them leads me to believe that they create at least 2 different Konkave bearings: a lower and higher grade Konkave depending on the model.
Physical:
The bearing on the left was taken from my Big Fun and is a lower grade KK bearing that comes deshielded with 10 balls. The higher grade KK bearing on the right is from a Freehand One Aluminum.
After deshielding the right bearing, there is a noticeable difference between the cages of the two bearings. Secondly, the inner race on the higher grade bearing (right) has a slight rounding on the inner race while the lower grade bearing is cut flat. Thirdly, there are more tooling marks on the outer race on the lower grade bearing.
Upon closer inspection of the side profile of each bearing, there some minor differences. The lower grade bearing on the left has larger flat shoulders that reduces the concave area of the bearing when compared to the higher grade KK on the right. Some light machining marks are also present in the valley of the bearing.
Performance:
When comparing how each Duncan bearing plays in a yo-yo, the differences become a little bit less obvious. Both bearings are smooth, quiet, and play to my preferences with a bit of light lube. The lower grade bearing is just a tad grittier than the higher grade KK which may just be due to the looser manufacturing methods. I noticed that there was a bit of black residue that came out of the lower grade bearing from when I applied excess lube, so a good cleaning may smooth it out even more. The higher grade bearing plays nearly identically to any of my official Dif-e-yo KKs.
I find both bearings are better than most Centertrac, Buddha, or generic bearings I have played with. Only YYR DS, NSK bearings, and One Drop 10 balls are at this level of smoothness.
Duncan KK Conclusions:
While the lower grade bearings are a bit rougher and not as polished as the higher grade KKs from Duncan, both bearings are excellent players for just about any yo-yo. It makes economic sense for Duncan to loosen some of the manufacturing specifications when producing KKs for some of their more affordable plastic yo-yos. On the other hand, their higher grade KKs used in higher end and player signature models are some of the best bearings currently used in yo-yos (in my opinion).
What about Magicyoyo KKs?
Here’s a Magicyoyo KK from a Y03 Hertz. It comes deshielded, 8 balls, and an identical cage on the front and back (Duncan KKs have a round flat cage on the backside). The side profile is about the same as the higher grade Duncan KK. There are a bit of light machining marks but is generally less noticable compared to the lower grade Duncan.
Performance-wise, the Magicyoyo KK is not nearly as smooth and quiet as either Duncan bearings. There is a slight grittiness, ringing, and reduced sleep time for this bearing, but it still plays very well. I would consider a clean, lightly lubed, and good condition Magicyoyo KK bearing is probably just slightly below the lower grade Duncan KK and better than a Centertrac.
While the 3 Magicyoyo KKs I’ve had have been great, they lack the precision and higher manufacturing quality that Dif-e-yo KKs have.
12 Likes
Okay, so genuine Dif-e-o KKs and “A-grade” (for lack of a better term) Duncan KKs are made to a higher manufacturing standard and generally perform better than generic alternatives. Thank you for showing how to easily tell the difference between them too.
Out of curiosity, why does Dif-e-o specify the need for a break-in period for their KKs?
2 Likes
I can testify to this.
The majority of my collection is Duncan and I’ve seen variance in the concave( or KonKave if you prefer) to the affect of some with 8 ball and others 10.
2 Likes
This advice probably spans from way back in the early 2000s when all bearings came heavily lubed from the factory. Back then you would break-in a bearing by playing it until the lube wore down to your desired responsive preference.
Playing with a new bearing also helps to wear in any rough spots from manufacturing, although this was less of an issue on high quality bearings like Dif-e-yo or NSK. The difference was more pronounced on coated or teflon bearings.
4 Likes
Upon a more detailed read I agree with this in full .
I’ve actually felt that I have reviewed 3 possible different kk bearings from them as some have even come deshielded.
And a similar MYY situation too.
1 Like
Difeyo is known and highly regarded for quality. Others are a crap shoot, some good some not.
5 Likes
I still use original 8-ball Difeyo bearings that I had from the 90’s/early 2000’s. They play perfectly 20 years down the line.
I have little problem with any modern bearing to be honest. They all work well enough for me.
7 Likes
I love thr bearings very good never had issues they have borrow license correct difeyo
1 Like