This is just wrong.

No they were packaged and had z stacks installed. Never opened.

And Yoyofactory has the rights to hubstacks, not to the general idea of bearings being attached to the side of a yoyo.

Which goes to show how Yoyofactory used a preexisting idea and expanded upon it.

I didn’t know that, thanks Samad, but this this just furthers my point because it shows how this doesn’t only happen in the yoyo world.

Although I agree that Duncan should have let Yoyofactory know that they were going to use something similar to hubstacks for the momentum, I don’t think there is a need to get angry about it. All of this is assuming that Yoyofactory did actually get upset at the hubstack thing, if they didn’t then good for them.


I would debate further, but I’m lazy :stuck_out_tongue:

Lets just agree to disagree.

I don’t think YYF should be mad I mean so what if duncan momentum uses z stacks YYF yoyos will still be better and have longer stack spin time and duncan new metals haven’t been that good

You haven’t tried their two new metals have you?

Haha agreed


I’ve tried them but they’re not as good as I though, I think I’d rather use my m1 or my cousins new breed.
I didn’t think they were terrible but they felt kinda average and I feel that YYF metal play better (I have tried YYF metals .

who cares… I just want one

That is just your preferences really.

wow, it’s on sale now…what ever happened to originality?

stacks are good for 5 minutes then it gets boring…

:frowning: ~gorilla_YO808

Really guys? you are going to get bent out of shape because of this? I mean let’s remember that many of the yoyo’s became popular because of duncan’s design. Without that there wouldn’t be the yoyo’s you have today. Instead of being mad at copying, (which if you guys think all yoyo’s have similar features) lets be happy that places are improving. Competition helps other companies start inventing new ideas and sometimes helps lower prices. Yeah the old stuff might not have been broken but I’ve always believe you shouldn’t stop at mediocre but should always strive for perfection. Lets all try to get along and let YYF get over itself.

First of all. They are called Spinning Side caps. And second of all, THEY SUCK.

Who cares if duncan tried to remake Z stacks. They failed horribly at it and wont ever get anywhere with them. YYF should just let it go and realize that nobody can fully remake a version of stacks that even comes close to their own.

No offense to other brands but really think about it.

Synergy: FAIL

Synergy Caps: FAIL

Spinning Side Caps: FAIL


The quality doesn’t matter as long as they make money on it. YYF don’t like it when people make money on something they popularized (and patented). I think that the momentum is not violating any patents, but I’m not 100% on this.

I don’t there’s that much success in stacks at all. People just take them off. They’re fun for a very short amount of time, and people say yoyos play smoother without them.

I agree with this as well.

They’re at the shop now. Check em out.

I really don’t see the big deal.

As long as Duncan isn’t putting actual Z-Stacks on their yoyos, this shouldn’t be a problem. If companies weren’t allowed to copy each other, we would have a very limited amount of different yoyos, and their quality would probably worse.

You are basically saying that because Toyota came up with a Hybrid engine (I don’t know if they did or not, just throwin a name out there), no other companies should be allowed to use one in their cars.

Spinning Side caps aren’t bad at all?

Everyone needs to stop caring about the legal and moral issues with yoyoing, go play with your toys kids.


i like the mayhem and you dont… yoyoing is all about preference

I am really tired of hearing people say this. Duncan did NOT copy Z-stacks. Z-stacks use an O-ring to hold the stack in place. Momentums use a screw to hold the spinning side cap in place. Same function, but different ways to do it. If we wanted to be that technical, then we should all be mad at YF for putting a bearing in their yoyo and stealing Tom Kuhn’s idea. Or Having their bearings lock into place, Like YYJ was the first to do. Or putting a response system in their yo-yo like Eric Wollf first did. Its not that, “OMGZORZ THEY STOLE IT FROM YYF.” They saw yyf’s own take on spinning side caps, and put their spin on it. I say that it is “yyf’s own take” because it was NOT yyf’s original idea. They just made it better.

DrYoYo: Alright, On to YoYoFactory. Where did the idea to put Bearings on the outside of the yo-yo come from?
Hans: The Miroc. I’d put spinning things on yoyos before (Stunt Pilot) but when I saw that video of Guy Heathcote doing those tricks with the Miroc I flipped.

I had to have one. I’m a player first, demonstrator second, and a manufacturer a distant third and I couldn’t wait to play with that thing. When it arrived and I threw it, the bearings immediately shot off and disappeared under the couch. I was so frustrated. I just wanted to play with it and have the experience. Honestly, if the Microc had just worked right, YoYoFactory Hubstacks probably wouldn’t exist today. I want kids to have good experiences with yoyos, not the frustration I felt digging under my couch. I was given this responsibility and hold it to the highest importance. Take the Brain for example. Yomega does a good job with that. Why would YoYoFactory need to make a clutch response yoyo? We would have nothing to add.