YoYoJam SpinFaktor X (SFX) Review


Weight: 66.0 g
Diameter: 57.0 mm / 2.24 inches
Width: 41.0 mm / 1.61 inches
Gap Width: 3.0 mm or 4.5 mm
Gap Type: Fixed
Response: YoYoJam Silicone Pad
Bearing Size: [thin, 0.125 x 0.500 x 0.187 in] or [size C, 0.250 x 0.500 x 0.187 in]

Out of the box

I picked up a red SFX in Wilmington, DE on the way back from a business trip a couple weeks ago. Comes in the standard YoYoJam package, which is fine by me. Stock, it is responsive with a thin bearing (YYJ speed bearing included in package). Great idea, because out of the box anyone can play with it!

Looks and Feel

This is one gorgeous looking yoyo. The translucent red is a great color and I love the way light shines through it. The contrast of red plastic, to metal, back to plastic is very distinctive and like nothing I’ve seen before. Like other recent YoYoJam models that use plastic, the four circles for the plastic mold are under the caps on the outside of the yoyo rather than in the string gap. Smart move.

Two complaints: On the outer rim of my SFX there is a small bubble inside the plastic, a minor imperfection that has a negligible effect on play. The other complaint is that the caps are rather uninspired for such a revolutionary new yoyo (in my opinion).

The SFX is angular, but not sharp. The metal bands between the plastic bulge out so that they don’t follow the arc of the plastic. This gives a little more detail and character to the feel in your hand. I appreciate that subtlety. Don’t worry; the transitions between metal and plastic are aligned perfectly.

SFX w/ Dark Magic


My first impression is that it is very, very smooth. I applaud the Solid Spin axle system. As you may know, previous YoYoJam models had the bearing seated on plastic. Now it is seated on the same bolt the axle is screwed into. Vibration is virtually gone, or at least negligible. The next generation of YoYoJam yoyos is truly here.

Unless otherwise noted below, I played with the SFX unresponsive.

Binds: Binds are nice and tight as one would expect with silicone pads. I was quite concerned at first because binds felt slippy, but was relieved that the silicone seemed to break in for me. Whew.

Stability and Agility: Like most unresponsive yoyos, the SFX will spin as long as you need it to, and with the metal bands in the body it keeps its axle’s orientation steady, though not as well as a metal rimmed yoyo like the Dark Magic. At 66.0g the SFX feels neither light nor heavy, and the weight distribution makes it a very versatile yoyo, allowing you to play fast and maintain stability and yet change axis of play easily (e.g. gyro flops).

String Tricks: If you like full-sized yoyos, you’ll like the SFX. It is nice and wide, about the size of a Dark Magic. The shape makes the string fall right in the gap, which is plenty wide to hold many layers of string.

Slack and Whip Tricks: Great shape, great weight. I don’t like heavy yoyos for this stuff, and the angular shape slides the string into the gap easily. Made me feel like a pro at whips and slacks!

Inner Rim Grinds (IRG): It doesn’t seem worth trying an IRG on the SFX. It’s just not made for it. It has very shallow rims with the caps on, and considering how small the caps are I’m not going to bother removing them.

Grinds: Not great for grinds in my opinion, but not terrible. The plastic in the middle or on the edge really grabs onto your skin as it spins. Some people like that, but I prefer a brushed metal finish, a bead-blasted finish, or the textured plastic used on the Atmosphere or New Breed. For me the angular shape of the SFX is not conducive to grinding either.

Speed bearing: The YoYoJam speed bearing spins just fine. Not quiet, a little noisy, super-unresponsive. I noticed that the C-shaped clips that hold the shields in are not flat, so when you go to take them out, they pop out easier than other bearings I’ve used. Nice little detail.

Responsive play: I’m not a big fan of how it comes stock. The thin bearing creates a relatively small gap. With a mere trapeze, you can feel friction and vibration. It forces you to do your tricks fast, which I suppose is not always a bad thing. I stuck in a single gray shim and put a little more lube on the bearing and enjoyed it much more. I do like the fact that it comes responsive for beginners.



This a great overall yoyo with character. The aesthetics are amazing. It clearly was made primarily for string and slack tricks, and it excels in these. It feels fast, stable, and has a great weight distribution. The price is a fanastic deal for a yoyo that performs like this.

It’s weakest areas are its grinding surfaces, virtual absence of IRG ability, and plain-looking caps.

While my interest in YoYoJam had been waning, the SFX brought it back. I can easily recommend the SFX due to performance, price, and especially uniqueness.

Thanks for reading!


Nice in depth review I really want to try one of these

Nice review I want one now.

Is there a little more space between the axle bolt and the sidecap on the bearing side? With mine, on the axle side there is only a minuscule amount of space between the sidecap and the bolt, but on the bearing side I can press on the sidecap and it flexes and clicks like there’s an air bubble or something.

I ask because mine seems to tilt that way if it’s going to tilt. It’s probably just my throw, but I don’t know for sure.

On mine, the space between the axle bolts and the sidecaps look identical on both sides. Not sure what you mean by an air bubble, but perhaps one of the caps is bulging outwards? One of my Aquarius caps was stamped backwards. I assume the axle bolts are both flush with the plastic around them?

I think the most significant source of tilt from a straight throw is the string position on the bearing. If it’s not in the middle of the gap, the yoyo will tilt and its axis of spin will rotate. That’s one nice thing about KonKave bearings, is that it centers the string for you. They are NOT necessary though (I only have 1 in my entire collection).

However, the best remedy for tilt is to practice getting a straight, strong throw consistently (work on straightness before strength), and also to observe and rectify the yoyo while doing string tricks. You can maneuver the string to tilt the yoyo back into alignment.

I’ve tried the Prototype. It. Had. Absolutely no vibe, even on quite a bad throw (I know mine kinda sucks) And… It can handle almost anything, horizontal, slacks, whips, multiple layers, and it doesnt snag! It doesn’t really grind well though, given that it’s mainly plastic. It also has no air bubbles (if only this remained for the production version)
This is one good yoyo I’d want to get. Definiely one of the best in it’s price range.

I don’t have my SFX on me at the moment, but I’m sure I remember that the axle bolts are where they should be. It seems that there would be a much more dramatic effect on play if they weren’t. Perhaps the sidecap has a bulge in it or something.