It’s important to mention the whole spring thing was driven by the Londinium myth of the Londinium profile. These machines were only generating around 7 .5 bar at the puck during normal use and the pressure dropped quite rapidly. I got this from the very few videos on YT that showed this sort of thing.
The commercial machines have always been able to make at 10 or 11 bar and drop to around 7 or 6 bar at the end of the shot…rather than the 3 or 4 bar of the Londinium. This gives espresso of a completely different quality and the group manufacturers basically laughed at the idea of a single spring, as you don’t get a good pressure “profile” and a too fast drop off in pressure.
I tried to explain to people, but you always get shouted down by those with other reasons for wanting to promote something that is effectively wrong. The group Londinium use should be using 2 springs, but no doubt was dropped to 1 by Londinium to allow a smaller machine without tipping and less flexing.
This video shows an L1 without a case flexing (even though it’s only using 1 spring)
The second video shows 45 degree angle metal arms added to stop the flexing, but it caused another problem now on a much more rigid machine.
I do believe these videos got removed eventually from Home Barista, I will leave you to your own conclusions as to why. Fortunately I was able to grab them before they disappeared..
Now to be fair, the case adds more rigidity, plus the additional drip tray and water tank adds more weight to help against tipping but it should be clear why they only used 1 spring
