# [Gaggia Classic 2019] Shortening the OPV spring to lower bar pressure



## Haskell (Aug 13, 2019)

Hello

Two months ago I got my first espresso machine and it is the Gaggia Classic 2019 RI9480/11, And it was a let down for me to know that there's no way to lower the factory default bar pressure of ~14 bars, Then I stumbled upon this Bulgarian fellow showing how he managed to lower the bar pressure by shortening a spring inside of the OPV, and he explained it very well with pictures and videos here: https://coffeeforums.bg/viewtopic.php?t=97

I googled around for someone else who has tried the same solution and I couldn't find any, even here, so I wanted to ask before trying it myself, because it is irreversible.

I don't speak Bulgarian and I used google translator, but it failed to translate the whole page since it includes some weird HTML tags (I suppose) so here's a rough translation of the post (refer to the original post for pictures + videos)



> Since the valve is plastic and does not adjust like the classics before 2015, I did the following operation.
> I unscrewed the two screws that hold the machine cover. When removing the cover, be careful because it is gripped by two earth cables (do not interfere with modification).
> The plastic OPV is mounted above the pump. It includes a red hose and transparent silicone, which overflows the excess pressure.
> 
> ...


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## L&R (Mar 8, 2018)

Yes it works, just cut ring by ring from the spring and measure the brew pressure till desired value. I made a few Gaggia Babies this way(same plastic Philips safety valve inside).

BR


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## Haskell (Aug 13, 2019)

Awesome news! how come no one here mentioned this solution! I'm just waiting for my pressure gauge to arrive so I can start cutting down some rings!

one more question, are these spring can be bought separately if I mess mine up ? or maybe if I decide to have multiple springs to switch between multiple pressure settings


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## L&R (Mar 8, 2018)

The whole OPV assembly is cheap so if something goes wrong, you can fix it easy.


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## Haskell (Aug 13, 2019)

Thank you !


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## itapio (Aug 13, 2019)

Interesting topic. I'm getting my new Gaggia Classic Pro in a couple of days. I'm quite newbie with these so could you explain what is the negative effect of the factory pressure ?


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## ashcroc (Oct 28, 2016)

If you want reversible, just put a pre-2015 OPV in. No need to remove the one that's in there as it'll never open & it's in a different position.


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## L&R (Mar 8, 2018)

For fitting pre 2015 expansion valve in GC2019 you will need the valve, a Teflon tube with connectors and a brass 1/8 fitting for the pump. It won't be cheap but worthwhile.

BR


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## Haskell (Aug 13, 2019)

@L&R I've followed the linked instructions and shortened the spring and it went as expected, way better tasting shots/lattes!

The hardest part was actually unscrewing the spout from the portafilter ! I saw people using vises to unscrew it, I did it with a small spanner and some hot water and freezer time, I'm not sure if the freezing helped, but I think the hot water did, took me two days to unscrew ?, it was a magnificent moment!

Check out my video for before and after the adjustment, and pay attention to my faulty gauge as it floats above zero (around ~1bar) even if there's no pressure applied, I was shooting for 10bars, You think I'm golden ?






Thank you for your help.


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## L&R (Mar 8, 2018)

You could have shortened it more but now still is better than stock.


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## Haskell (Aug 13, 2019)

L&R said:


> You could have shortened it more but now still is better than stock.


 aren't we aiming for 10bar static pressure ? explain more please.


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## Haskell (Aug 13, 2019)

@L&R this topic seems controversial: https://www.home-barista.com/espresso-machines/why-difference-in-pressure-between-blind-filter-and-brewing-t10807.html


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## L&R (Mar 8, 2018)

Lately I adjust all Classics to 9-9.5 bar static and have very good results in the cup, just speaking from experience. You can make your own experiments as well and find out what works best for you. Cheers!


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## Haskell (Aug 13, 2019)

@L&R I see, I just placed an order for an adjustable valve to play with the pressure and decide what works best for me (thanks @nunu1 for the blog post), cheers.


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## L&R (Mar 8, 2018)

Good choice a little bit expensive but good.


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## Haskell (Aug 13, 2019)

L&R said:


> Good choice a little bit expensive but good.


 The one I linked is a fixed at 9 bar and not adjustable, I had to contact the seller to ask and they changed the item description to note that it is not adjustable so I had to cancel my order, I think I will hold on buying an adjustable valve and I will cut a bit more of my spring. Cheers.


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## coffeeuser1 (Sep 21, 2019)

You're welcome @Haskell. Yea cutting the spring also works.

The adjustable one is nice if you'd like to experiment with different brew pressures. In my case I found best results at 8-9 bars.

I've also noticed that pressure has changed by 0,5 bar after couple of weeks, so I guess its nice to have ability to fine tune. However I don't think I've noticed a difference in the cup, so no worries there.

PS: Once you're done with the pressure adjustment I'd strongly recommend installing the PID. It really made a huge difference in the cup. I posted a how-to guide for Gaggia Classic on my blog: https://yirga.pl/gaggia-classic-2019-pid-rex-c100 in case you're interested.

Goodluck!


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## Cor (Sep 18, 2019)

SCR Motor controller. ebay, £1.50.

;o) Cor


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## MrShades (Jul 29, 2009)

If you don't really want to cut your springs, and want the ability to do great 6.5bar (and 5 bar) extractions as well - then check my OPV spring mod kit here:

https://www.coffeeforums.co.uk/topic/50289-mrshades-gaggia-opv-spring-mod-kit?do=embed


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## pagu (Oct 10, 2021)

Hello

I'm quite late here but the topic seems yet relevant as Gaggia keeps selling his Classic with annoying setting issues. I have just received mine and I was quite disappointed not to be able to use the unpressurized baskets properly. As I couldn't wait running a couple of shots I did cut off 5mm from the 24mm spring and was able to get some nice and tasty coffees. I nevertheless ordered a kit from MrShades to get some springs with a proper ring at each end. A cut spring doesn't seem to me as a clean solution on the long run. BTW, I oriented the cut side of the spring toward the silicon tubing, seems more reliable to me rather than the other way as there is an increased risk of jamming the valve on the pump side by pressing it unevenly.

Big thanks to you all for this simple and effective way to morph in a couple of minutes with cutting pliers, or by ordering a nice kit, what appeared to me like a coffee burning box into a nicely working espresso machine!

As the temperature is fairly unstable, too high most of the time, the next mod will be a PID. I haven't yet made a choice between a micro-controller board - versatility - and a ready-to-use PID box - simplicity.


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