Commercial Edition Plunger

When using the commercial edition plunger, water pressure escapes from between the portafilter and the machine when I try and get 5 or more bars of pressure. I have replaced the portafilter, basket, seals and used both a competition filter screen, a new standard screen, and my original standard screen. Everything is as tight as it can be. However, despite numerous attempts with different coffee grind sizes, it won't manage 5 or more bar of pressure without water and pressure escaping from the top of the porta filter. Had to go back to the original plunger. I have been using the ROK for over 3 years so am fully versed in how to operate it. I have tried pre-soaking the grounds and pre-pressurizing but nothing works.Disappointing, to say the least.

Works perfect and easy to install

Nice upgrade. Works well and is easy to install. Small downside is that the additional material removes some heat.

It's a nice upgrade, not necessary, but nice. I have used a rok of sort for 12 years plus now. Had original, upgraded it, got a brand new one and upgraded with this screen. Using a flair also regularly it is nice to have the visual feedback and sort of settled on a better pre infusion time as a result

Excellent addition to the machine. Give great feedback on shot profiles. I’m pulling much better shots!

Great upgrade!

The fact that you can see the pressure during the process is a good thing.
But the product quality is not really good, it looks like a DIY job. It not an industrial finish

An essential accessory for the GC-ROK this has shown that i was actually over pressurizing my machine. and now I'm able to pull much more consistent shots.

Easy installation, great upgrade for consistency, but it makes the heat regulation more difficult. The additional metal needs more pre heating.

The pressure gauge adds another dimension to my espresso making. I am still waiting for a replacement part as my old machine needed a service.

My first espresso maker and it looks great in the corner of my kitchen. Love my GC

Plug and play. Works great

First one sent to me didn't work. ROK replaced it within a process that felt sufficient, and not onerous.

It works, so it's got that going for it. However, the relatively heavy steel frame for the gauge noticeably reduces the available water volume when filling, as well as increases the thermal mass to make my coffee noticeably cooler. It also sits quite loosely in the plunger, making it feel a lot less premium than it actually is.
The scale on the gauge is also slightly illogical; getting more than 10bar of pressure out of your ROK takes a very strong person, and the gauge goes to 20bar.

Delivery was quick, communication good and the product is flawless.

Good but highlights silicon screen can not go above 6bar pressure.

I ordered a commercial plunger to replace the ordinary one in my ROK Espresso Maker so that I could see if it was reaching the right pressure to produce a true espresso. The first one delivered was faulty, letting through the water as soon as I put it in the chamber. After contacting the ROK support and carrying out various checks, they delivered a replacement which works perfectly. However, the most pressure I can generate, regardless of the grind or firmness of tamping, is between 6 and 7 bars so falls short of the desired 9 bars. I guess that strictly speaking, you could say that the ROK does not produce a true espresso but in my mind, it still makes an excellent cup of coffee far better than most domestic machines costing 2 or 3 times more. I was lucky in that the commercial plunger I bought was on special offer of around £28, reduced from £44 which I think is a bit excessive for what you get. So, all in all, it does what it’s meant to - reads the pressure - and I’m happy.

I've been using my ROK for a year now getting some good results. I didn't have a pressure gauge on it so I never knew what pressure I was achieving. I decided to add the Commercial Edition Plunger to take the guesswork out of it. It makes it easier to get the grind right and end up with a consistent pressure and more consistent results. Glad I took the plunge :)

After a long wait for production, I received and installed the piston with the pressure gauge.
It's easy, efficient, and performs its function perfectly; a must-have for anyone who likes to have even a little control over their ristretto.
This makes the Rok the best manual espresso machine for my needs.

The pressure gauge is very useful for coffee preparation. However, it needs to be better secured. For example, a screw through the stainless steel and plastic piston. It should always be installed as standard.