Boba U4

I’ve got my hands on Boba U4s and they are so damn tactile with no pre-travel too. However, I find them fatiguing after typing for some time (writing code and replying emails). I’m using 62g variant.

Do you guys have any recommendations on switches that won’t be too fatiguing for me? Do I really need to go for less tactile switches or linear instead? Hmm.

Appreciate any help!


I find U4’s fatiguing as well. You might try lubing the stem legs, or replacing them with Gazzew “silent tactile” stems - kind of like U4’s but with a shorter, lighter bump.


I’m actually going to test some professionally-lubed U4 Bobas using lighter 55 G springs, but I wasn’t planning on doing that anytime soon. [I have them now, though.]

To answer the OP’s question, you can use the other OUTEMU custom silent stem, the “Silent Sky / Silent Forest” stem that is also known as “Silent Tactile.”

It is meant to be about as tactile as an Ergo Clear, and while it does not feel exactly the same, it is about as tactile.

You can run them in a fairly tactile housing at around 62/63.5 G, or a less tactile housing [like Cherry] at 60 or even 55 G.

They were originally meant for the teal Silent Sky housings, but those housings are outdated. In those housings, they were fine and poppy and tactile at 62 G using the default springs. You could alternately use the OUTEMU Blue Ice housings if you wanted something a little less tactile and pingy [get them while you can at pennies on the dollar!]

I found a good combination to be Silent Sky stems in an MX Clear housing with 60 G springs. It’s poppy, and a little more tactile than Browns.

It’s either that, or try to reduce the tactility and increase smoothness with U4 Bobas. U4s will function at 55 G in the Boba housing, you may have to mess around with it to make that happen. Interestingly, the Silent Sky stem needs maybe 68 G for full function in that housing, even though it is less tactile. [You should be able to get away with 62 G]


Thanks for the suggestion. I guess I’ll try Outemu Silent Forest stem with Boba housing.

As for your suggestion on Outemu Blue Ice housing, were you referring to these? Transparent top and bottom?
I’m from SEA, so buying from hbheroinbob is not really an option for me.

if you like everything about bobas except for the fatiguing weight, I would really recommend lubed and filmed bobas with a 55g spring, it retains the nice tactile bump and the quieter sound profile while making them very easy to actuate with a light tap. as someone who used 60-70g linears for a while, 55g bobas are a lovely sweet spot for me on tactiles.


Honestly, I couldn’t tell you what a Blue Ice housing looks like, because I haven’t received mine yet. I have no experience with them. I just understand that they may be a little smoother and perhaps less tactile than the default Silent Forest housing.

Since you already have Boba housings, that’s a good option for you.

I checked, and they highly recommend 68 G springs or greater for the Silent Forest stems in the Boba housing. [This is a higher weight than with Cherry housings.] Keep in mind tho that this is in order to achieve its rated tactility. You can use lower weights, but will lose some tactility.

I think I’ve gotten Silent Forest to work okay in Boba housings using 60 G TX springs, and that was with a pretty crude lubing job. 62 should be sufficient, but you’ll have to try it.

In less-tactile housings [such as TTC Gold Brown V2], I can run Silent Forest stems just fine at 57 G TX, and also the new 55 G [large] TX springs. It functions fine, but I think it is a little slower. Honestly, I think the Silent Forest stem wants at least 60 G springs in order to return well. Silent Forest with 60 G TX in the TTC Gold Brown or Cherry MX Clear housings is a very comfortable weight.

As Dr. Doof’s post suggests, lubed U4 Bobas with 55 G springs should work. I am testing this out for a reason.

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I just made two more lubed U4 Bobas using 55 G Spirit springs.

They are definitely more tactile than my 55 - 60 G Silent Forest switches. However, I find them a little sluggish, and more likely to slow down on the upstroke.

This could be a fairly gentle switch to type on if lubed properly. I’ll have to try some others.

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I described this same feel in a different post. I bought the 68 G and then swapped out the spring for 62 G and couldn’t notice a difference at all. I think it’s the “high friction” feel of the switch. @Deadeye’s theory on the tension against the leaf spring makes a lot of sense since the spring swap did not make a noticeable difference.

I suspect that over time the high friction feel will eventually diminish when the switch gets broken in, but how much, and how long it would take would be the real question.


I definitely understand what you mean by “high friction” feel, and it is very real.

I, too, am curious about whether it diminishes upon break-in.


I feel very similarly. I got some silent sky tactile stems from Gazzew directly, and I love them so much I have more on the way :smiley: I like a little less tactility, so I’m having fun trying them out in different housings I have laying around. I may make a batch of them with Gat Yellow housings soon, because I have a bunch of those laying around


As the reviews of the Silent Sky said, “The Stems Steal the Show.”

They are basically a silent light tactile, more tactile than the ‘Browns’ like Silent Brown and Aliaz. Can be very bouncy, depending on spring. [I keep mine reasonable.]

They fit in a lot of housings:

-Cherry MX Clear and allegedly other “Cherry-class housings.”

-TTC Gold Brown V2


-Silent Sky [teal housing]

-OUTEMU Blue Ice


And those are just the ones I know about.

I feel that the Cherry MX Clear housings are the right balance of tactility and smoothness for this particular stem. The Silent Sky housings were more tactile, but also scratchier and had problems with the leaf.

The Boba housings are a very stable/non-wobbly candidate, but they require higher weights.

Sounds like Gat Yellow housings would probably work, as well.

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Found this thread and just ordered 150 bobas with silent stems off Gazzew. He says I don’t have to lube them but we’ll see.


OP I thought the same about bobas, and ended up sticking with v2 raras.
I can only recommend 62 or 63.5g springs with them though since at those weights they feel like snappy ergo clears, while at 67g they feel almost identical to T1s. You also need to lube the tactile legs slightly or there’s oddness with the tactile leaf that’s hard to describe, but they’re great if you can get them lubed properly.


Woah, you have V2 RARAs?

I got in on the GB in October, they still haven’t shipped yet to Canada.

Can you tell me what they are like? Do they resemble Penguins [also 63.5 G, trying to copy the MX Clear stem] Or are they like Everglide Jade in a more tactile housing?

I’m trying to figure out the lubing and spring-swap situation before they arrive.

I see. But these switches aren’t as readily available as Boba U4s. Do these switches have pre-travel?

In order to answer some questions that came up here and in other threads, I quickly rebuilt a few switches today:

-55 G U4 Boba with 55 G L TX springs: This is interesting.

The new 55 G (L) 16 mm springs from TX are a less troublesome way to build 55 G U4 Bobas.

The 55 G (L) 16 mm springs are heavier at the top, so they descent and actuate with greater force, while still being overall a 55 G spring.

This makes them function more easily with U4 Bobas than other types of 55 G spring.

So if you are doing an amateurish job of lubing U4 Bobas, the 55 Large springs will help, as they enhance the operation of the switch.

I also rebuilt a couple of Silent Sky Bobas into 60 G TX switches.

With 60 G TX, they will give you way less trouble than 55 G regular springs, while still being fairly light. The Boba housing is fairly tactile, though, so friction/resistance and overall force will be greater than with a light-tactile housing.


Silent Sky Bobas has a nice ring to it. I’m probably gonna call them this when people ask what switches I have.

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Yeah. Silent Sky makes for good combination switch descriptions.

I built some TTC Gold V2 with Silent Sky so they became Golden Skies, or Golden Silent Skies.

And you can build Silent Sky Penguins and so on.


Penguins in the sky. The stem works good with tactiles.

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Okay, so the professionally-lubed Bobas arrived and I tested them. There were fewer than I expected. However, the testing didn’t alter my earlier conclusions much:

-55 G U4 Boba is still a little dodgy. It wants to catch on the upstroke.

The 55 G Large TX U4 Bobas I assembled today fared better. 55 G Large is the way to go if you want 55 G U4 Bobas.

-68 P Silent Sky Boba was underwhelming. There just isn’t enough actuation force at the top - the Silent Sky in the Boba housing wants more. Just use 60 G + regular springs for Silent Sky in the Boba housing.

-The builder made the most interesting Pro Purple in a Boba that I have experienced so far. It is a Pro Purple Stem in the white Boba housing with a 65 G TX spring. Lubed with 205g0 and also filmed.

This Boba makes a deep, muffled sound. Pro Purple is not a silenced stem, in fact is very loud, but actually sounds almost reasonable in this arrangement. Tactile force and weight is like a heavier Brown, kind of like what BOX Burnt Orange is to BOX Brown.

I could almost see myself typing on this. I’m not sure there’s any real reason to build it, but this is the best Pro Purple in a Boba housing.