Should you care about switch stem wobble?

Updated: Jun 29



After tackling the “touchy” subject of plate flexibility here on this blog a few months back, it is now time to cover another similarly complicated matter that is guaranteed to rile up the mechanical keyboard crowds: switches' stem wobble.


While I see a lot (and I really mean A LOT!) of keyboard content creators out there showing switches stem wobble and even rating switches based on how much wobble they have, I have literally never seen a single one of those creators explaining why switch stem wobble matters (or not) to them.


Actually, if I have to be fair to one keyboard content creator here… that would be Thomas Ran (a.k.a Chyrosran22 on YouTube), who minced no words to say that he doesn’t really care about stem wobble.


But then again, Thomas had only addressed switch stem wobbling in situations where the lack of it was actually some sort of novelty, such as in his many videos covering Hi-Tek “space invaders” switches in NMB keyboards of the 80's and 90’s (switches that are notorious for having very little wobbling in any direction, given how large its “moving base” is and how low its center of gravity ends up being). At any rate, he never portraited the presence or lack of wobbling as necessarily a good or bad thing.


Now, to the required disclaimer: most of what I’ll cover here is based on my personal opinion, of course... So, if you dislike switches with a lot of stem wobble, please don’t feel offended by my views in this article. As I usually do on my writing (for this Blog and for my YouTube videos’ scripts), I’ll try to be as factual and "data driven" as possible (although, as we'll see later, it is quite difficult to have any real "hard data" on this subject) instead of relying too much on my own personal preferences.


So, let’s start by defining what is too little or too much stem wobble.



How to measure stem wobble (and what is too much or too little)?


And here we are faced with the first problem: How do you measure switches' stem wobble? While I guess it could be possible to create some contraption that can measure the fractions of millimeters a switch stem can move in each direction, no one has ever bothered to create one... Which may give us the first indication that this is less of a problem than most “stem wobble haters” would be willing to admit.


So, what we get instead is usually someone moving the stems with a tweezer in front of a zoomed-in camera lens and then telling you if that is too much, too little or acceptable stem wobble. In other words, very subjective and with no scientific approach whatsoever.


When reviewing three variants of “Holy Panda” switches in one of my previous videos, I even admitted so myself, that the Invyr Holy Panda stem wobble, while present, was not a problem in my personal opinion (which is basically the only thing I could rely upon when covering this topic):


“As for stem wobble, while the Invyr is a bit worse than the other two switches, I can't see anything out of the ordinary here... At least to me, I'd say you will not have any problems using taller keycap profiles such as SA or MT3.”


But then I got “grilled” (of course...) on my opinion by a viewer on the comments section:


I guess here we have a great example of the subjectivity of this theme, and how one’s pre-existing opinions and biases (maybe acquired by seeing content creators out there repeating something a thousand times) might influence how one hears and understands what was said:


I never said the switch has little or no wobble! What I said was that "I can't see anything out of the ordinary" with the Invyr's wobble, that “stem wobble seems perfectly fine” on the Yok and that “I didn't see any major issues with stem wobble” on the Glorious. In other words, I didn’t say the switches didn’t have stem wobble. What I said was that the existing wobble was not a problem for me. And there is a bit of a difference between what I actually said and what the viewer implied I said.


To me (as to Chyrosran22 as it turns out) a certain amount of switch stem wobble is simply not an issue. I have tried dozens (so many dozens that might be approaching a hundred at this point) of different keyboard mechanical switches of all types throughout my life and very rarely have I ever faced a situation where I felt that stem [and the consequent keycap] wobble was a hindrance to my typing experience.


And to illustrate what I would consider to be very low, low, medium, high and very high levels of switch stem wobble; I shot this short video where I compare seven stock switches* (no lube applied, other than whatever factory application there was in each case) with varying degrees of stem wobble:


a) NMB/Hi-Tek Black “space invaders” (clicky): very low level of stem wobble

b) Gateron CJ** (linear) and Durock POM (linear): low level of stem wobble

c) Kailh Box White (clicky) and Glorious Panda (tactile): medium level of stem wobble

d) Cherry MX Brown (light tactile): high level of stem wobble

e) Alps clone –alps.tw Type T1 (clicky): very high level of stem wobble


Cherry MX style switches were tested with SA, MT3 and Cherry profile keycaps. Hi-Tek "space invaders" were tested with Cherry profile and the Alps clones with OEM profile.



A few interesting quick observations out of this video:

  1. The amount of perceived wobbling between the worst and the best cases are not as big as we're led to believe;

  2. The perceived wobble when moving the stem with a tweezer and then wiggling the keycap with your finger can be quite different in some cases. Such as with the Hi-Tek black "space invaders" and the Kailh Box white clicky switches, where they feel very wobbly with the tweezer directly on the switch, but then feel much more solid when wiggling the mounted keycap.

  3. Switches with loose housings tend to feel more wobbly, since the top housing will move a bit in the same direction you push the stem, than in switches with very tight housings. So, I guess there could be a case to use "switch films" if you want to reduce stem wobble as much as possible.



What are the potential problems that can result from switches' stem wobble?


Out of all of the switches I tested in the video, ONLY the Alps clones have a level of stem wobble that I consider to be problematic. And the reason for that is that its stem wobble, in conjunction with the rest of the switch condition, design and materials, result in one thing we can all agree to be bad: key binding.



A) Key binding


For those not familiar with the concept of “key binding”, it refers to a situation where the stem won’t slide down (or rebound) properly when the keycap is pressed in a corner. In other words: the key press feels stuck.


And that is exactly what I get on my Filco FKB-107J-AI that sports those Alps clones… By the way, there will be a video covering this keyboard, its switches and my mods to fix their issues, of course!


But unlike the Alps, Cherry MX’s design is such that key binding is rarely a problem, and the reasons for that are at least twofold:

  1. Cherry MX’s stems have a larger base (it is a rectangle, but more "squarish" than on the Alps' stems), which makes them inherently more stable than Alps;

  2. Cherry MX’s stems are much more immune to dust contamination than Alps.


Two issues that, when combined in old, dirty and poorly maintained Alps boards, can cause a lot of key-binding problems.


So, on Cherry MX switches, unlike on Alps, even if the switch is of a lower quality (higher manufacturing tolerances for example) and is a bit wobblier than it should, chances are you’ll still not have keys binding when you hit them off-center on a reasonably well-maintained keyboard. Hence, this is basically a non-issue for modern mechanical keyboards (that are essentially all based on Cherry’s MX switch design).



B) Rattle


Another potential problem with stem wobble is a much more subjective one: rattly switches. Since the stems and keycaps have more room to move in the north-south and east-west directions, you might have some level of rattle when shaking or running your hands through the keys… Two things most normal typists never do to their keyboards.


And the enthusiasts that could perceive such rattle (since, let’s face it, we are constantly listening and paying attention to the sounds that come out of our keyboards, unlike normal typists) will usually lube their switches’ rails, which will mostly eliminate any potential rattle that could come out of switches with high levels of stem wobble. So here, again, stem wobble would not be a glaring issue.



C) Bad "typing sensation"


And finally, the last stem wobble potential problem I can think of would be a "bad sensation" when typing on a keyboard with wobbly stems/keycaps...


Did I ever feel anything like this in any Cherry MX keyboard I ever typed normally on? No.


Are there people out there who claim they can feel something like this and find it to be a problem? I’m sure there are!


But then again, of all the potential problems deriving from switches’ stem wobble, I’d say this last one is THE most subjective of all, and thus the least likely to be a real problem to the majority of mechanical keyboards users out there.



Conclusion: should you worry about stem wobble when buying keyboard switches?


Well, I cannot tell you if you should or should not care about switch stem wobble in your keyboard… Naturally! This is highly based on personal preference and typing style.


But, having said all that, I think I can make a pretty convincing argument here that, at least for the vast majority of typists out there, the answer to this question should probably be: No.


Switch stem wobble is, in the grand scheme of mechanical keyboards’ things, much more inconsequential than other more important variables in a switch design, such as the type of switch (linear, tactile or clicky), materials used and their smoothness, lubrication, the spring weights, the length of the stem pole, how tight the two halves of its housing are, and even the presence of the 2 extra prongs in PCB mounted switches as opposed to plate mounted ones.


But, because anyone reviewing mechanical keyboards’ switches absolutely HAS to mention the switch stem wobble thing, you can rest assured that this topic is not going away anytime soon on keyboard related content on the internet… That much, I can guarantee!



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