Londinium R24 vs. ACS Vostok

#1: Post by **LevaMayBe** » February 2nd, 2023, 2:39 pm

Hoping to learn more about this machine as used in the US. Clearly it's gorgeous, and can make amazing espresso. Wondering how it achieves temp stability in the group. The website says just walk up and pull a shot no temp management needed. How does that work - surely it is an HX machine? I have used an HX for 10+ years and as far as I know HX machines need a cooling flush - mine does according to the grouphead thermometer. Also how is the heat up time? The US model is specd with a lower power element in line with out 110v electrical standard. With half the heating power how long does it take to warm up? How do you like the app? Does it work well? How often do they update it? Looking at this machine vs the ACS Vostok - which has 2 boilers, 3 PIDs etc.very tough to write the check with no hands on time...

#2: Post by **Jake_G** » February 2nd, 2023, 3:00 pm

Hey Surindha, welcome to HB!

You're likely to get some very polarized responses from a handful of outspoken folks who love Londinium machines, and an equal and opposite group of outspoken folks who don't.

I haven't used one, but have watched many of these conversations pan out and have a large group of friends who have used many machines and settled on the Londinium as their daily driver.

Now, to your first question:

LevaMayBe wrote:Wondering how it achieves temp stability in the group. The website says just walk up and pull a shot no temp management needed. How does that work - surely it is an HX machine? I have used an HX for 10+ years and as far as I know HX machines need a cooling flush - mine does according to the grouphead thermometer. .

Remember that pump driven machines have a completely different thermal equilibrium that levers do. On your machines with a group head thermometer and flushes for cooling, the water is flowing at a steady rate throughout the shot, and it is consistently coming into the group from the heat exchanger in the boiler.

On a lever such as the Londinium, the chamber above the puck is very quickly filled with water from the HX when you pull the lever down and raise the piston. This water rushes into the chamber at an astonishing rate, and then, there is no more input into the group from the HX. The group idles at some steady temperature that is lower than your brew temp, and the water from the HX rushes in at a hotter temperature. The result is a steady shot temp just by walking up and pulling the lever.

The R24 actually manages shot temperature by controlling the pressure at which the preinfusion takes place. The idea being that a higher pressure will permeate the puck quicker and carry more heat into the chamber than a lower pressure fill will. It seems more complicated than it is, and - more importantly- it has been shown to work and be quite repeatable.

I don't know what the warm up time is, but I'd guess it's somewhere around an hour before everything is totally at "walk up and pull a shot" temperature stable. Someone with hands on experience can correct me with actual data saying the group temp is stable after 43 minutes or 38 minutes or whatever. Put it on a schedule and wake it up an hour before you want coffee and you'll be happy. Heating element size actually has little to do with the machine being ready to pull shots, as the boiler will be pressurized after no more than 20 minutes even with a paltry 1000W element. The big thing is how long it takes a pressurized boiler to shed heat to the group, and that's a function of how big the group is and how cool you keep your home.

As for the ACS, it is certainly the more technologically advanced machine. 2 boilers, actively heated group, triple PID, etc... you also get the rather legendary (although different and modified) LSM group. Lots to like about it on paper, and many, many folks swear by this group or derivatives thereof.

Cheers!

- Jake

February 2nd, 2023, 4:48 pm

Thank you so much for the super detailed and helpful response. Really appreciate it.

The ACS provides more control, but more complexity and more points of failure PIDs, screens, buttons etc. R24 seems more focused on simplicity. On temp stability - thank you I had assumed there was a thermo siphon. I appreciate the point about warm up - flushing the group would probably accelerate the process too. I may look to see what idling power consumption is - feels like boiling a kettle all day. I used a Defect for a few weeks and loved the 5 minute warm up...consumed a lot more espresso intraday

Just really feeling the romance of the lever!

#4: Post by **Jake_G** » February 2nd, 2023, 5:39 pm

There is indeed a thermosyphon, but since all the water enters the cylinder above the puck nearly instantly, the intra-shot temperature profile is very predictable.

Remember, you don't have a constant fresh supply of hot water coming in from the HX like a pump machine. Just a giant "slug" of water that sheds heat as the shot progresses.

#5: Post by **Cuprajake** » February 2nd, 2023, 5:55 pm

To counter

The ACS is ready in 15mins due to the group heaters the boilers less than 10 mins.

Theres a whole bunch of electronic on both machines. The lr24 uses an app to change pressure

Most acs owners keep the stock infusion pressure from factory and tune temp with the pid in the boiler and group

Both can be tank or mains fed

I believe the Vostok is getting a rotary pump also as the lr24 is super quiet

#6: Post by **Primacog** » February 2nd, 2023, 8:29 pm

LevaMayBe wrote:Hoping to learn more about this machine as used in the US. Clearly it's gorgeous, and can make amazing espresso. Wondering how it achieves temp stability in the group. The website says just walk up and pull a shot no temp management needed. How does that work - surely it is an HX machine? I have used an HX for 10+ years and as far as I know HX machines need a cooling flush - mine does according to the grouphead thermometer. Also how is the heat up time? The US model is specd with a lower power element in line with out 110v electrical standard. With half the heating power how long does it take to warm up? How do you like the app? Does it work well? How often do they update it? Looking at this machine vs the ACS Vostok - which has 2 boilers, 3 PIDs etc.very tough to write the check with no hands on time...

It seems to me that the Londinium and a hybrid lever like the vostok are not really directly comparable and belong to different categories. Both in looks and features, the Londinium r24 seems to be basically a traditional spring lever with the addition of a thermosyphon system that makes temperature in the grouphead more stable and that has a gear pump that supplies preinfusion pressure which can be set by a bluetooth app. It is best used left switched on throughout the day and relies also on its mass to retain heat. However there is no direct temperature controlling ability in the r24 but according to their maker, the temp is indirectly changed by changing the preinfusion pressure according to an application of charles law.

While a hybrid lever also uses a pump to control the preinfusion, it is able to directly set and vary temperature independently in the group head, steam and brew boilers. It does not rely on heat retention by mass or thermpsyphon to heat the grouphead as that is independently heated by cartridge heaters (in faxt the grouohead is often insulated from the boilers) and so the machine can reach optimal temp generally in 15 mins or so and electricity savings can be gianed by leaving it off when not used.

Unlike the r24, a hybrid lever can change the temp of any component while keeping the preinfusion pressure constant. Hence u can isolate the effect of both variables.

So the question to be asked is - what actually does one want - basically the looks and limited functions of a trad spring lever with merely the abiliy to comtrol preinfusion pressure, or the ability to directly change the temp of any component and to arrive at that temp in minutes? If u just use light or medium roasts and alternate with dark rpsts as i do often in tje same session, the ability to change temp at a moments notice is very valuable - and a hybrid lever may be the right choice in those circs. But if u just use one type of roast usually and just want a limited enhancement of a trad spring lever and prefer the look pf a trad spring lever, then the Londinium may be the better choice for you.

But bear in mind - a hybrid lever can do everything that the r24 can do but you dont have to use the extra features if u dont want to. But if u want to use them, they are there for u to exploit at any time.

If the OP wants the silence of a trad spring lever, then neither the r24 or a hybrid lever are suitable because both use pumps. In that case, a true trad spring lever is best - i owned an izzo pompei for a long time and that is a trad apring lever that gave rock solid performance for totql silence.

Another hybrid lever machine for the OP to consider is the Nurri L-type SA Leva that has similar features as the vostok and also having a modified La San Marco double spring grouphead but from a purely manual perspective and a distinctive aesthetic look....i own one and it replaced my izzo and it is really great to use...

https://www.nurri.coffee/portfolio-item ... a-machine/

#7: Post by **Primacog** » February 2nd, 2023, 8:44 pm

LevaMayBe wrote:Thank you so much for the super detailed and helpful response. Really appreciate it. The ACS provides more control, but more complexity and more points of failure PIDs, screens, buttons etc. R24 seems more focused on simplicity. On temp stability - thank you I had assumed there was a thermo siphon. I appreciate the point about warm up - flushing the group would probably accelerate the process too. I may look to see what idling power consumption is - feels like boiling a kettle all day. I used a Defect for a few weeks and loved the 5 minute warm up...consumed a lot more espresso intraday Just really feeling the romance of the lever!

If u want the full romance of the lever experienxe and dont mind flushing the grouphead and want simplicity, then i suspect the better choice for u is actually a traditional spring lever like the izzo alex or the profitec 800 or the bosco sorrento. The r24 has a gear pump to set the pre infusion pressure and a bluetooth app to control it which are also potential points of failure.

Since u r worried about points of failure, u may be worried about maintenance and repair needs and do not want to do it yourself. If so a valid issue is that both the r24 and the vostok are direct sale products and u will need to do the maintenance yourself usually.

On the other hand profitec and izzo run on a dealership network. Also if u want a hybrid lever that is supported by a dealer, the Nurri leva is the only hybrid lever that is sold under the usual dealership model and already has dealers in quite a few countries such as canada, uk, belgium, australia and in asia. Apparently clive coffee is considering bringing in the nurri to the states as well.

P.s. do u mean Decent as opposed to Defect?

#8: Post by **DaveC** » February 2nd, 2023, 10:04 pm

I don't believe the pump on the LR24 is a gear pump.

February 2nd, 2023, 10:17 pm

You are correct. They are using a small form DC rotary vane pump.

#10: Post by **Primacog** » February 2nd, 2023, 10:35 pm

DaveC wrote:I don't believe the pump on the LR24 is a gear pump.

My bad - my recollection was incorrect. The r24 uses a rotary pump actually https://londiniumespresso.com/store/lr-24