Since the general idea of spring levers haven't changed that much since the 1950-1960 i assume(apart from things like a Strega and probably other fun machines i don't know about), what innovation has happened with the bigger spring levers that are being made today? .... Are we talking steaming capability, temp stability, shot quality, ease of repair and maintenance or something else entirely?

I think it might be useful to distinguish two issues; simply because each of them has a slightly twisted story: 1) capacity versus conveninece versus size 2) technology versus shot quality.

!: Lever machines were replaced by p[ump group not for reasons of shot quality or equipment reliability, but for capacity: a two group pump machine make as many cups per hour as a four group lever machine, since the group does not need to recover. If you are renting space in downtown Milan, you want to produce as much espresso per square foot as possible. But oddly, for the home, single group lever machines made in the fifties, or for sleepy seaside inns since then, are nicely sized for counters, while commercial gear is not. For the home user, the convenience advantage of a semi-commercial pump machine over a commercial one is substantial, whihc is why even LM is making small sized machines now. But the advantage of a semi-commercial lever machine over an old single group lever is basically nil.

2: It always took major gyrations to make espresso as well with a pump machine as with a lever machine; look at all the stuff in an E61 group to mimic a few qualities of lever machines. Now we have double boilers with adjunct group heaters and flow profiling; and after a whole load of research, it's best to start hot and ramp down to cool, and to preinfuse, then high pressure, then drop it gradually. Sound familiar? Eventually, the programmable machines will consistently beat levers; but for now, it's "everything old is new again"

Recently, there have been lots of arguments about lever groups still in production, as used by Bosco, Astoria, Bezzera, etc. versus legacy groups. For many people, this problem is moot, since they are not inclined to do the occasional fabrication and machining required to maintain a legacy group. What I fail to understand is what the people who can do the fabrication are arguing about -- if you want a 10 bar Astoria style spring on your old Lambro, why not make one? There seems to be an element of deliberate antiquarianism creeping in. May I suggest the society of creative anachronism for you, or at least more of a steampunk ethos rather than excessive reverence?

CoffeeBeetle wrote: So phrasing the question as simple as i can: I buy a old commercial lever, if it's scaled up and need new gaskets i fix these things but i don't mod or improve it and i buy a Londinium(or something else in that range, i don't know a lot of levers in that price range) and i use them both of them as my daily machines. What difference am i going to experience?

Probably not a lot, if it's made by someone truly skilled and familiar with how to build a lever group machine, like Kees or Bosco. These particular makers take the base components of the groups they source, but modify and tweak things to achieve a better result. They're not just bolting on something they've bought off the shelf from the manufacturer and slapping their name on it. With many of these standard commercial lever groups, there are options not only for how the group heats, how the pre-infusion water flows into the group, but also things like group sleeve designs (some models have identical groups but more inlet holes), etc.

I think technology is gradually bringing us closer and closer to what the classic lever espresso machine has long been capable of doing. But depending on the maker and the complexity, the reliability of all those electronics and added parts might be eclipsed by the simplicity of a well thought out lever group.

For specific innovations that have had a positive impact on how a lever group functions, I quickly think of the Conti Prestina with its brilliantly engineered cammed linkage that significantly shortened the physical arch of the the lever arm, without sacrificing shot volume. It also made it easier to pull, amplifying the barista's arm effort, more than just pulling on a regular lever.

Every time the Prestina is brought up i hear great things about it. I have been thinking about getting one and restoring it but the thread from DrGary made me hesitant, i don't have 22 months and a couple of friends with blowtorches and industrial cutting equipment.

Interesting to hear what i kinda suspected, that the actual day to day espresso isn't going to be too different. So something like the Londinium is more of an old lever with new materials, than it is a modern lever? I don't mean this in any bad way, just trying to understand what is really behind some of these commercial levers.

I participated in the other thread so I hope you don't mind me weighing in here.

I've had the opportunity to compare shots of the exact same coffee and grinder on both a vintage commercial Faema lever and also a Bosco Sorrento. The shots did taste different but not vastly different. The Bosco shots were noticeably heavier body and aggressive around the edges, but still "smooth" enough to fit a classic lever spring profile. I measured the spring pressures of both groups, the Bosco spring got up to 8 bar where the comparison Faemas (both my President and a friend's Lambro) had spring pressures ranging between 6.5 and 7.5 bar. The preinfusion flow rate was also set higher on the Bosco. After adjusting the flow rate to be closer to one of my President's groups the shots tasted nearly identical to the ones I pull from my group with the stronger spring.

The improvements made on modern commercial levers have more to do with modern conveniences of using the machine than they do with changing the way it makes shots (with the exception of those double spring groups that get up to 14 bar or so, why they did that I'm not sure). Improvements like boiler auto-fill, modern OPVs and even better dispersion screens (I replaced my clip on screens from the '50s with modern IMS ones because the old ones were just aweful) are more designed for ease of use and maintenance than for taste.
TomC's mention of cam designs improvements is an interesting one I hadn't thought of. I'm not sure what improvements were made if any on the "Bosco" group but I did notice it was significantly easier to pull that my old Faema even though the Bosco had a stronger spring; maybe I just need to relubricate my cams.

As far as the quality of vintage lever groups go, the "Quality Espresso Palanca" group is an exact replica of the old Faema Zodiaco group dating back to the late 50's. It is still in production and powers many a coffee shop in Spain.

CoffeeBeetle wrote:Every time the Prestina is brought up i hear great things about it. I have been thinking about getting one and restoring it but the thread from DrGary made me hesitant, i don't have 22 months and a couple of friends with blowtorches and industrial cutting equipment.

Interesting to hear what i kinda suspected, that the actual day to day espresso isn't going to be too different. So something like the Londinium is more of an old lever with new materials, than it is a modern lever? I don't mean this in any bad way, just trying to understand what is really behind some of these commercial levers.

Not sure what you mean by "a modern lever". A lever is pretty basic technology, about as basic as you can get, especially commercial-grade machines. The major differences are around how they get brew water (dipper, modified dipper, HX), none of which could be considered modern, and how the grouphead is heated (again, very basic mechanical heating). IMHO, the main things one wants are solid build, good materials, and shot-to-shot thermal stability.

With any spring lever there are 2 basic considerations:
1) ergonomic, mechanical operation and physical characteristics.
2) quality of the coffee produced.

The difference between commercial, and non commercial machines is usually a matter of the ergonomics and not so much the quality of the coffee produced.

My Brugnetti Aurora is an heat exchange system. I think the londinium l1-p is a hybrid hx.

Balthazar_B wrote:Not sure what you mean by "a modern lever". A lever is pretty basic technology, about as basic as you can get, especially commercial-grade machines. The major differences are around how they get brew water (dipper, modified dipper, HX), none of which could be considered modern, and how the grouphead is heated (again, very basic mechanical heating). IMHO, the main things one wants are solid build, good materials, and shot-to-shot thermal stability.

I don't mean a lever that is using a new system, but simply a lever machine that was designed and produced recently. Like a Londinium or Strega is what i think of when i say modern lever. I understand that the design behind these levers may be old but the machine as a whole isn't.

From what I observed/read/heard, many of the vintage levers were quite in tune with the technology back then and there's not much differentiation if you're talking just about the shot quality (just tiny differences and probably 'different' would be a better descriptor than 'better'). Even after seeing some of the modern levers today, it seems that we're only catching up to the vintage technology rather than surpassing (may change soon with more manufacturer getting into levers???).

However, you do get some of the convenience and refinement factors, ie the autofill, PID, optional plumb-in/tank operation, and active heaters. The trade off however, is you do introduce some wear-and-tear part and more possible areas to go wrong (20 years down the road). I personally love how my 40-years-old Aurora is an only-manual-fill system with sightglass - which means I can drain off the boiler cold in no-time (no potential temperature shock to element), and there's no complicated wiring needed for a Gicar box. However, it does mean the operator needs to pay attention to the sightglass (do you watch your car's gas fill level?). Also, another quirk for being a pure heat exchanger is the warm up time is longer - the benefit is it is not likely to overheat when serving a party - not that I need it but that's what the machine was designed for initially I suppose. For quicker warm up, I've added an active heater (modern twist) to help the warm up time (no concern about warranty and it is a reversible mod ). Most of the levers (in fact all espresso machines - pump or lever) do have some quirks but most of the time it is quite easy to live with (or you choose one that you can live with).

Another major difference in my observation was the manufacturing approach. Back then, the manufacturing philosophy were more artisanal (labor was cheaper back then I guess) than today's built-to-a-price-point approach. If you browse through the levers gallery thread here, you will find that there're so many vintage beauties that you could never get your hand on, each with its own unique personalities (of course, there're also some ugly ducklings in the vintage category ). Then, fast forward to today, you get a polished stainless steel box, then another stainless steel box, and end with yet another stainless steel box (Londinium, Strega, Bosco, Achille, Alex, Profitec etc etc). Kees Idrocompresso was an exception but as you see, the price is exceptionally high as well and thus demand is little - it's no longer in production for that reason.

If you can get a vintage lever and restored to new, chances are they are as good/better as modern levers , and looking better. Just make sure the important spare parts (seals etc) are not a headache to source. That's my 2 cent.

p/s: Edited to avoid spreading misconception. Thanks John.

samuellaw178 wrote:Then, fast forward to today, you get a chrome box, then another chrome box, and end with yet another chrome box (Londinium, Strega, Bosco, Achille, Alex, Profitec etc etc).

Are any of those chrome? Bosco is polished stainless steel.