# Londinium seals v Cafelat



## 4085 (Nov 23, 2012)

I know this has been talked about before, but I could not find anything specifically comparing the two. I have just changed the seals on my L1. I bought Cafelat as I was unsure if my skill sets would stretch to this as I believe the Londinium seals can be very tight to get on. I replaced the Londinium seals because even after greasing twice, I could not get the bite point correct. With a 10 to 12 second pre infuse, there was no difficulty in extracting 30 pls fluid wise, but the bite was wrong. Occasionally I had to Fellini but I just put that down to one of the many variables in the coffee process.

My pal Al came down this morning, and replaced the seals. On re assembling, everything seemed fine on the first shot, but the subsequent shots the bite point was even worse than it used to be and I know have to Fellini two extra times!

So, I did see @Arelim suggest that the Cafelat seals actually took time to bed in but once they did all was fine. So, can I ask users who chose Cafelat seals if this matches their experiences and I should just give it a bit of time to bed in, or possibly have we done something wrong or any other (useful) comment are welcome, especially from Brexiteers........LOL


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## arellim (May 9, 2016)

Do you mean the bite point is now very high? I have never had that with my Cafelat I dont think (I might have written the opposite though- I cant remember!).

I do have a few drips now coming from my seals, but performance is spot on and so I'm leaving it well alone. Biting point still at 10 oclock and all seems to work well.

The reason I changed from Londinium to Cafelat was that, even with greasing etc, the Londinioum ones seemed to dry up and start slipping after 6 months- to me that is unacceprtable. I must be 2 years into the Cafelat and no slippage (although there is a slight drip once every 15 minutes I would guess.


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## 4085 (Nov 23, 2012)

@Arelim

Yep, I want the bite point is way too high. I was looking back over previous threads and you said this

I much prefer the cafelat seals but they did take a while to bed in for some reason. The Londinium ones fit better but they're made of rubber and can dry out. Pretty simple to change whichever way you go.

SO, I wondered if it was not unusual t have a high initial biting point followed by a more normal


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## The Systemic Kid (Nov 23, 2012)

David, I fitted Cafelat seals to a Mk I LI some time back - Tom organised a group buy. Seals improved bite point from the start - biting markedly lower than with the previous seals.

If my poor addled brain is correct, wasn't there some discussion on the dimensions of some Cafelat seals not being ideal for LIs?


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## 4085 (Nov 23, 2012)

The Systemic Kid said:


> If my poor addled brain is correct, wasn't there some discussion on the dimensions of some Cafelat seals not being ideal for LIs?


 Would be most interested matey if you came across that. I simply bought mine from the link that has been posted up here several times. No doubt, I have the wrong ones!


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## Fez (Dec 31, 2018)

arellim said:


> The reason I changed from Londinium to Cafelat was that, even with greasing etc, the Londinioum ones seemed to dry up and start slipping after 6 months- to me that is unacceprtable. I must be 2 years into the Cafelat and no slippage (although there is a slight drip once every 15 minutes I would guess.


 I guess everyone is different, I'm more than happy to clean and regrease every 3-4 months. I feel better knowing that everything has had a nice clean


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## mathof (Mar 24, 2012)

I've tried both kinds of seals and they both work splendidly in my early L1. I can't even tell which is in there now without dropping the group to look.


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## 4515 (Jan 30, 2013)

I tried cafelat and left them in for a good 6 months. Bite point was too high and wasn't positive. I tried wrapping PTFE around the groove that the seal fits in but had no better results. Changed to Londinium and bite point was much lower and much more positive.

There was a thread where this was discussed and the tolerance of the group was blamed for the poor performance. Seemed to be a case of a poor workman blaming his tools to me as I'd increased the diameter of the seal 'bed' with the ptfe.

All I gained from it was that they work for some but not for others which is a shame because the idea of a silicone seal with longer life appeals to me.


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## Fez (Dec 31, 2018)

How long are everyone's Londinium seals lasting?

I'm at around 10 months and when I pulled the piston out for a clean earlier this week they looked as good as new


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## NickR (Jul 1, 2011)

The seals fitted to my machine from new were never much good. and I replaced them after about a year. The Londinium seals transformed the machine and lasted for about 5 years. The bite point was still good at the end of this time, but they were leaking. I replaced these with Londinium "precision" seals about six months ago. The bite point has never been lower. I've not measured the absolute max shot volume, but the average must be around 40g. I've got some Cafelat ones ready for next time, but I'm hoping that the present ones will keep going as long as the first replacements did.


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## 4085 (Nov 23, 2012)

Has anyone made a video or got some tips as to how to fit the new seals. I have seen a photo of someone poisoning two cable ties to stop the seals slipping into the wrong groove, but after that photo, I would be making the process up! Last night I took the piston out and found the seals were definitely in correctly, however there was grease sitting in the open groove, so, I thoroughly cleaned the grooves. I then found the piston chamber to be dry. I am 100% certain it had been greased earlier in the day, so I applied a little more, worked the lever 25 times, took the shower screen off and there was no excess.

I then loosened the grind off a little, having read more about darker roasts and puck saturation on the Londinium website. The first shot this morning the lever bite was approximately where it should be, though still perhaps slightly high, however I got drips at about 6 seconds. I tightened up ever so slightly tamping in the normal way and the lever was back to biting far too high. So, I slackened off ever so slightly and only used the cheap Chinese levelling tool and di not tamp further and the shot was better. SO, it seems I need to explore dose, grind and tamp. From the comments people give, it seems that even fitting the new Londinium seals does not guarantee to fix the problem.

It is more of an annoyance than affecting the coffee. Luckily my tastebuds are not that good so I do not really notice it that much, but I would like to get it sorted! Perhaps when one of the merry band of travelling forum members who happen to be more adept than I at playing with spanners, comes to the Newcastle area, I can make them a reasonable coffee after they have changed my seals again!


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## Norvin (Sep 10, 2014)

dfk41 said:


> Has anyone made a video or got some tips as to how to fit the new seals. I have seen a photo of someone poisoning two cable ties to stop the seals slipping into the wrong groove, but after that photo, I would be making the process up! Last night I took the piston out and found the seals were definitely in correctly, however there was grease sitting in the open groove, so, I thoroughly cleaned the grooves. I then found the piston chamber to be dry. I am 100% certain it had been greased earlier in the day, so I applied a little more, worked the lever 25 times, took the shower screen off and there was no excess.
> 
> I then loosened the grind off a little, having read more about darker roasts and puck saturation on the Londinium website. The first shot this morning the lever bite was approximately where it should be, though still perhaps slightly high, however I got drips at about 6 seconds. I tightened up ever so slightly tamping in the normal way and the lever was back to biting far too high. So, I slackened off ever so slightly and only used the cheap Chinese levelling tool and di not tamp further and the shot was better. SO, it seems I need to explore dose, grind and tamp. From the comments people give, it seems that even fitting the new Londinium seals does not guarantee to fix the problem.
> 
> It is more of an annoyance than affecting the coffee. Luckily my tastebuds are not that good so I do not really notice it that much, but I would like to get it sorted! Perhaps when one of the merry band of travelling forum members who happen to be more adept than I at playing with spanners, comes to the Newcastle area, I can make them a reasonable coffee after they have changed my seals again!


 This is how I fitted mine.

https://www.coffeeforums.co.uk/topic/47857-londinium-piston-seals-how-i-fitted-mine/?do=embed

I have loads of the copper shim, it made the job so much easier, let me know if you want any.


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## Paul Pratt (May 15, 2013)

working dog said:


> I tried cafelat and left them in for a good 6 months. Bite point was too high and wasn't positive. I tried wrapping PTFE around the groove that the seal fits in but had no better results. Changed to Londinium and bite point was much lower and much more positive.
> 
> There was a thread where this was discussed and the tolerance of the group was blamed for the poor performance. Seemed to be a case of a poor workman blaming his tools to me as I'd increased the diameter of the seal 'bed' with the ptfe.
> 
> All I gained from it was that they work for some but not for others which is a shame because the idea of a silicone seal with longer life appeals to me.


 I just want to add the seals I made were purely from a standpoint of having them in silicone and not rubber. There is nothing fancy about the size, the dimensions will be the same as a standard seal used on all CMA groups for the past 30 years. It is the same seal I use in our little Robot coffee maker and presumably the same as the Fracino Londinium machines for the fist 3 or 4 years.

The newer lever groups are very beautiful but could be much better. The piston design is very lazy - having a fixed piston on the end of the rod is not ideal, it is much better to have a design whereby the piston has a bit of free movement from the main rod, that way it can find the centre of the sleeve and stay there throughout the up and down movement. If it is fixed it relies 100% on the machining and tolerence of the factory to be ultra tight. The fact that people discuss them on forums shows the group is not working as it should. There should be several years of life in a piston seal, no need to lube and clean or replace so often.

I did make a few new wobbly pistons for people and sent them into the wild with great results. However changing a piston is not something to be taken lightly and should be done at the source. The problem is again lazy manufacturing. The rod should be permanently bonded to the top knuckle but it is not and can undo when you try and remove the piston. It could result in the spring letting go when it is not meant to.

Can a humble seal affect the lever bite point? I don't think so, that would depend on pre-infusion time, grind setting, flow rate and pre-infusion pressure. Seals either work or they don't. Sure the silicone would have a bit more give to them compared with rubber. A lack of a back flow valve may also affect bite point. I've never see a large commercial lever without a check valve in it apart from some of these new levers.

Heres a video of where I would like to see the bite point.






At the end of the day use whichever works for you.


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## 4085 (Nov 23, 2012)

Paul Pratt said:


> At the end of the day use whichever works for you.


 I am more coming into agreement with Paul on this. I am certainly not an expert in this area but I have had 4 Londinium and never had a problem with the lever bite point until this one. So, having changed the seals from whatever was in to CAfelat, I am no further forward. I read as much as I could around the matter and started playing with grind coarseness, weight and tamping. Yesterday, I forgot to top up the beans in my hopper. The Mythos gives very varied results when there is not enough weight behind the beans pushing them into the auger. The resulting shot bit even higher and poured far too quickly. I adjusted everything including going back to weighing how much the Mythos ground in the time the button was set for and it was producing 17.7 gm as opposed to the 15.5 I wanted. Anyway, the next shot bit a lot better but still nothing like the angle in Pauls last video. I will continue playing around with it, but my conclusion is nearly at a stage, when I think a seal is a seal is a seal and other issues might also be at play


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## 4515 (Jan 30, 2013)

Paul Pratt said:


> Can a humble seal affect the lever bite point?


 Absolutely it can. The two materials are very different. One is like an elastic band whereas the other is much more rigid.

It is the only connection between the piston and the cylinder walls.

One works, the other doesn't (all of the time). Blaming the design is lazy. The group came first - the challenge, if you are is to design non OEM part, is it make something that works consistently. Remember Shell creating a petrol that killed Vauxhall engines - rather than blaming Vauxhalls engine design they pulled the product.


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## 4085 (Nov 23, 2012)

@working dog

Hi Andrew, so, which one works better in your mind then? Does the elasticity of the Cafelat work for or against? I get it, that they can each work well but differently. I am still finding the grab point a little high for my liking. The pre infusion is not dripping until about 11 seconds but the shot pours a little too fast so more work to do on grind and tamp. I never remember having these problems though in the past so something has changed! Where can I get what @Paul Pratt describes as the standard industry seal from? I ought to try them, then the newer Londinium seals as well. Presumably once I have a dose, grind and tamp I am happy with then the same test across the 3 seals should be fairly consistent?


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## 4515 (Jan 30, 2013)

Hi David

Cafelat didn't work for me. The grab point was much higher than with the harder rubber. Grab wasn't as positive and you never got that take up of the grab where you know it is going to be a great shot. Changed back to Londinium seals and all was instantly good again.

As Ive said in previous threads, I wish that they did work because they are much easier to install and should last much longer than the hard rubber ones.

I would be the first in line for a redesigned silicone seal that overcomes the issues that Paul sees in the group design.

Edit : Ive only used Londinium seals and the silicone seals. Not sure what the standard seal is (maybe the Londinium seal ?)


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## 4085 (Nov 23, 2012)

working dog said:


> Edit : Ive only used Londinium seals and the silicone seals. Not sure what the standard seal is (maybe the Londinium seal ?)


 The newly designed seal that Londinium supply, I think anyway, is only available through them. I may have picked it up wrongly but was there not some work done by them which resulted in them designing a slightly larger seal. Paul seems to refer to the industry standard so I am assuming that the new seals are slightly different to the old seals......


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## 4515 (Jan 30, 2013)

My seals were bought in late 2017. Think I ought to get a new set ordered as this will have been in the machine for almost 2 years now


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## Paul Pratt (May 15, 2013)

working dog said:


> Absolutely it can. The two materials are very different. One is like an elastic band whereas the other is much more rigid.
> 
> It is the only connection between the piston and the cylinder walls.
> 
> One works, the other doesn't (all of the time). Blaming the design is lazy. The group came first - the challenge, if you are is to design non OEM part, is it make something that works consistently. Remember Shell creating a petrol that killed Vauxhall engines - rather than blaming Vauxhalls engine design they pulled the product.


 I agree with the material comment, as I said silicone has more give than a hard rubber, that is undisputed. If there is indeed any give, I have never had a problem with it, if I can get the lever to grab at the horizontal there is no reason others can't either. The rest of your post I disagree with. I first made the seals maybe 2013 and I had never even heard of this so called lever slip nonsense. The fact is we have sold, believe it or not, close to 8k of them (we supply 3 brand users of that group directly) and I would say a dozen or so people have reported issues directly to me. As with all my silicone seals I test them myself for at least 6 months before we sell them and like I said I only heard of this slipping seal problem with that group AFTER I has done my testing and had them in the market for another 6 months.

The fact that you never read about other lever groups having slip problems would suggest this group has problems. It is not normal for users to have to change seals so often or to take it apart and lubricate.

From a historical point of view this group is the only commercial group I have ever seen not to have a wobbly piston and/or a check valve. Even the first Gaggia group from '48 has both of those, as do all my, Faemas, Cimbali's, Rancilios, Arduinos, Carimalis, Pavonis etc...

Your comparison with Shell makes no sense to me and I think you are confused. Seal problems I now understand date back to the first Londinium machines, so before I even started making silicone seals. The groups malfunction with the seals put in place by the manufacturer in Italy, it is well documented throughout these and other forums. To say my silicone seals caused an issue is completely incorrect - that is not to say my seals are any different to the OEM ones, dimensions are the same, materials are different.

Now the solution by some has been to make an oversized seal or add an extra seal to the top. It's all a work-around. Sure if it works it works, but the whole point of a lever group is the simplicity, you should not be having to clean and lube or change seals so often. That is all down to the poor design of the group.

If the demand is there I can make a new seal, but for the dozen or so people who have emailed us to say they don't work on their groups it is not something I have considered at this point.

I'm not posting here for a hard sell, far from it. Choose whichever works in your machine.


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## 4515 (Jan 30, 2013)

As Ive said repeatedly I would prefer to use the silicone seal but it doesn't work for me. I posted a video some time back showing the high grab point. Its not something that I am imagining or making up.

My point with shell was that they changed the product to work with all car models rather than blame Vauxhall. I'm sure you can see the parallel that I am drawing. Londinium seals give me a low grab point, silicone seals give a high grab point - theres only one variable changed.

More than happy to try a revised seal if you decide to make some.

Edit : Ive just re-read your reply. First you ask if a humble seal can make a difference, then you agree that the material can make a difference. Then you go on to dismiss 'lever slip nonsense' and tell us how many thousands of seals you have supplied. I run my own business and if I dismissed my customers issues as you do, I wouldn't have many customers.

Just my twopenneth Paul. Rather than defend a product which (in some cases) isn't fit for purpose, consider making a product that works as effectively as the OEM product, regardless of the group. If you are unable to provide that product then consider withdrawing the product or adding a disclaimer about the potential issues.

This is the second thread where you have defended your product to me. Not once have you offered me a solution.


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## Paul Pratt (May 15, 2013)

working dog said:


> Edit : Ive just re-read your reply. First you ask if a humble seal can make a difference, then you agree that the material can make a difference. Then you go on to dismiss 'lever slip nonsense' and tell us how many thousands of seals you have supplied. I run my own business and if I dismissed my customers issues as you do, I wouldn't have many customers.
> 
> Just my twopenneth Paul. Rather than defend a product which (in some cases) isn't fit for purpose, consider making a product that works as effectively as the OEM product, regardless of the group. If you are unable to provide that product then consider withdrawing the product or adding a disclaimer about the potential issues.
> 
> This is the second thread where you have defended your product to me. Not once have you offered me a solution.


 I have not dismissed my customers far from it, for those people who have contacted us directly I have bent over backwards to help them and found solutions. If you have not contacted us directly then what can I do? Presumably you purchased them directly from us. Quite a few who give me feedback are using my new pistons or a larger seal I have. I've helped people who were at their wits end with not getting other seals to work. I took the time to investigate many years ago and identified the issues. I put it out there for people to put pressure on the manufacturers of the group. I do not believe making larger seals is a good long term solution, making a better group is.

I do believe though there is some confusion over the OEM seals, because I keep saying the seals I have made are the same as the OEM. I believe you are saying the current seals from Londinium are OEM . You may find that those are the revised jumbo seals they make to fix the group problems.

Oh and the word "nonsense" refers to the group problems, not the feedback of users! For people to have to deal with these issues or even be aware of seals is not my experience of what owning a lever machine is about.

I wish you all the best with your machine.


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## 4515 (Jan 30, 2013)

Paul Pratt said:


> I have not dismissed my customers far from it, for those people who have contacted us directly I have bent over backwards to help them and found solutions. If you have not contacted us directly then what can I do? Presumably you purchased them directly from us. Quite a few who give me feedback are using my new pistons or a larger seal I have. I've helped people who were at their wits end with not getting other seals to work. I took the time to investigate many years ago and identified the issues. I put it out there for people to put pressure on the manufacturers of the group. I do not believe making larger seals is a good long term solution, making a better group is.
> 
> I do believe though there is some confusion over the OEM seals, because I keep saying the seals I have made are the same as the OEM. I believe you are saying the current seals from Londinium are OEM . You may find that those are the revised jumbo seals they make to fix the group problems.
> 
> ...


 These were bought as part of the forum group purchase so were bought directly from yourself but not by me.

Your seals are not the same as OEM - the material is significantly different, Dimensions may be the same but the seals are not the same. The seals I am using are the old style Londinium seals.

I'm willing to try any suggestions that you may have to make the seals work. Offering suggestions on this thread may help people other than myself. I still have the silicone seals in a drawer.


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## Paul Pratt (May 15, 2013)

Tks for the info. If you can use the standard rubber seals but the silicone do not work then I am at a loss as to why they are not working for you. In almost all of the dozen cases I have had where the silicone do not work, the standard rubber seals did not work either and only a custom larger seal would do the trick or a new piston.

I will check my stock of the sample seals I had made, they were a fraction larger on the OD and height. I am reluctant to adjust the hardness of the silicone to closely match the rubber as the silicone will lose some of its elasticity and become more brittle. If I have extra of the large seals happy to send some or refund for your trouble.


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## 4515 (Jan 30, 2013)

Thanks Paul

I'm not after a refund. If you have some over sized seals I am more than happy to try them and report back. The longevity of silicone seals is the thing that appeals to me.


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## coffeechap (Apr 5, 2012)

I have to disagree about the group being faulty the grab point on my LR is at the horizontal or lower. This is all down to preinfusion pressure, my LR with the pressure transducer will bite at 45 degrees if the preinfusion is set to 1.2 bar, if the preinfusion pressure is set to 3 bar the grab point is horizontal , so no fault at all with the design or permanent of this group. I have found a difference in using the genuine londinium seals and the cafe last seals. The genuine seals suffer far less from the slippage (which is a real thing) but neither suffer if the group is greased correctly.

also if you grind finer (as most londinium owners do) and allow for complete saturation of the puck during preinfusion you will not have the high grab point.

distribution is fundamental as well, as if there is any channelling at all then complete saturation at preinfusion is not possible and this will affect the grab point.

my advice, go back to basics, regrease the group and seals (which ever ones you are using), ensure drips from puck prior to raising the lever and make sure it is an even extraction across all of the base of the basket.


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## 4085 (Nov 23, 2012)

Right, school for thought please. I have two grinders. A Clima Pro and a Niche. Neither are really run in properly, therefore there will be inconsistencies in grind particle size. This in turn will cause pockets of less and more resistance for the water to pass through, which might cause my problem. I made 2 shots just now on the Niche. I had to guess where to put the grind at. The result was 20 seconds before even a drip appeared but when I released the handle it was far too high again and the shot poured to quickly. SO, I tightened up a couple of clicks, tamped in the same way, this time with 6 seconds to first drip, bite point at roughly the same place and again, poured to quick.

SO, is my problem my grinders rather than seals or inconsistencies in the lever?

Link in flooring post


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## 4085 (Nov 23, 2012)

correct link


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## Fez (Dec 31, 2018)

dfk41 said:


> Right, school for thought please. I have two grinders. A Clima Pro and a Niche. Neither are really run in properly, therefore there will be inconsistencies in grind particle size. This in turn will cause pockets of less and more resistance for the water to pass through, which might cause my problem. I made 2 shots just now on the Niche. I had to guess where to put the grind at. The result was 20 seconds before even a drip appeared but when I released the handle it was far too high again and the shot poured to quickly. SO, I tightened up a couple of clicks, tamped in the same way, this time with 6 seconds to first drip, bite point at roughly the same place and again, poured to quick.
> 
> SO, is my problem my grinders rather than seals or inconsistencies in the lever?
> 
> Link in flooring post


 Do you give the grinds a good stir/shake either in the cup or portafilter?

Just an edit to say that's only relation to your drips appearing faster even though you tightened the grind.


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## 4085 (Nov 23, 2012)

When using the Niche, the cup gets a good shake when I put it onto the pf. But this behaviour happens whether I use the Clima pro or niche


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## 4515 (Jan 30, 2013)

The video is the same as I experienced with the silicone seals


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## NickR (Jul 1, 2011)

> 19 hours ago, dfk41 said:
> 
> correct link


 As a long time L1 user I'm sure you know this. I have found that running some steam to get the element on and the boiler up to max pressure before pulling the shot, lowers the bite point considerably.


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## 4085 (Nov 23, 2012)

@NickR

thanks for the tip. I do not do that but I do normally wait to try to pull the shot at the top of the cycle. Am just warming up the naked to make sure my shot prep is ok then I will do what you suggest Nick


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## Deidre (Aug 13, 2019)

@Nick R I want to check this too, as sometimes I kick the boiler on for maximum pressure, before releasing lever, but haven't taken note of how it affects the bite point! ?‍♀

My bite point is usually quite high... similar to @dfk41. I have noticed variances in my preinfusion strategies have affected the bite point, but haven't paid enough attention?‍♀... will try to see if there is a pattern, henceforth!

(I often preinfuse with the lever down for just a few seconds, then do a longer preinfusion/screen sweat at the top (just before it reaches the bite point)... I think this strategy may make the bite point sit higher on mine.??‍♀)


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## Paul Pratt (May 15, 2013)

working dog said:


> The video is the same as I experienced with the silicone seals


 I agree it is not correct. I can get my bite point at just past the horizontal (pre-infusion at boiler pressure 1.1 bar) with silicone seals and I have half a dozen groups I test on. Try as I may I have never experienced any skipping of a lever. Obviously your experience and some others is different than mine and for that I apologise, but like I said so far in 5 years only a dozen or so people cannot use the silicone seals out of thousands of seals sold. Perhaps they don't report back!

When I look at the above video to me my first instinct is there is no water getting to the coffee. It looks exactly like a pull you do when the flow valve is off or just a tad open.



coffeechap said:


> I have to disagree about the group being faulty the grab point on my LR is at the horizontal or lower.


 Yes faulty is the wrong term, could be improved in my opinion with a wobbly piston and a check valve. I've never had any kind of skipping with mine either, firstly on the rubber seals and then on the silicone. Obviously there were some issues otherwise no need to make oversize seals and so many forums discussions many years ago. I did work with some people who just could not get a machine to work and a new wobbly piston with standard seals worked a treat.



coffeechap said:


> also if you grind finer (as most londinium owners do) and allow for complete saturation of the puck during preinfusion you will not have the high grab point.
> 
> distribution is fundamental as well, as if there is any channelling at all then complete saturation at preinfusion is not possible and this will affect the grab point.
> 
> my advice, go back to basics, regrease the group and seals (which ever ones you are using), ensure drips from puck prior to raising the lever and make sure it is an even extraction across all of the base of the basket.


 Exactly. Grind setting, dwell time, pre-infusion pressure etc..all have a major influence on the bite point.


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## 4515 (Jan 30, 2013)

Paul Pratt said:


> I agree it is not correct. I can get my bite point at just past the horizontal (pre-infusion at boiler pressure 1.1 bar) with silicone seals and I have half a dozen groups I test on. Try as I may I have never experienced any skipping of a lever. Obviously your experience and some others is different than mine and for that I apologise, but like I said so far in 5 years only a dozen or so people cannot use the silicone seals out of thousands of seals sold. Perhaps they don't report back!


 If you want to create some revised seals to resolve the problem for the few, having a product that all are happy with, let me know. I will test on my machine and report back.

Thinking about this, based on the same routine, same grind setting - one seal working as expected, the other not. Theres a chamber that fills with water and then is pushed out of the chamber via the puck, under the pressure of the spring. The only way that the grab point can be higher is if less water is entering the chamber or some of the water is escaping back over the seals. The water will not be compressing any further.

@dfk - a bit of a test that we could do. Ive just pulled a shot using 16g coffee - grind set to 32g @ 30 seconds and let it drain all the way until the puck is dry. Weights were 44.9g coffee in the cup + 16g water in the puck. I know that our coffee will vary but the amount of water dispensed should be similar. This would be an interesting comparison and give a dirty indicator on volume dispensed. I'd run both tests on my machine but it would mean destroying the Londinium seals to get them off.


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## Lefteye (Dec 30, 2014)

I have just replaced my seals on the LR with the Londinium ones I bought with the machine a couple of years ago. Have to say my lever grab position is about 80 degrees not far off horizontal. Not sure why your should catch so high. You'd imagine this would be due to a leak somewhere releasing the pressure. Have you removed the lever and looked at it again to check the seals are in the correct orientation and position. ?


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## Lefteye (Dec 30, 2014)

Could it be you're not getting enough water into the group? Could you have a block in the exit to the group such as grease etc leading to a short amount of water?


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## 4085 (Nov 23, 2012)

@working dog @Lefteye

Thanks for your thoughts. Chatting to a couple of folks, shortage of water is a consideration, except to say that this problem has always been present on the machine, before I started to fiddle on! Yesterday I put no coffee into the pf and measured about it filled a cup without problem on a single pull. I then repeated with a prepared shot on a single pull and got approximately 40 ml out. I recreated this just now and only got 24 ml out.


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## Paul Pratt (May 15, 2013)

working dog said:


> If you want to create some revised seals to resolve the problem for the few, having a product that all are happy with, let me know. I will test on my machine and report back.
> 
> Thinking about this, based on the same routine, same grind setting - one seal working as expected, the other not. Theres a chamber that fills with water and then is pushed out of the chamber via the puck, under the pressure of the spring. The only way that the grab point can be higher is if less water is entering the chamber or some of the water is escaping back over the seals. The water will not be compressing any further.


 I have found the larger seals today, drop me a PM. I only have a few as it was test mold.

For me it makes no sense, a seal failure usually results in a rusty spring and/or a leak from the top. The water has to go somewhere. From the videos David has posted, that to me would suggest low flow into the chamber, it resembles a pull you do when the boiler pressure is low as you can't be bothered to wait for it to heat up properly. A low boiler pressure does not force the water into the puck.

My shot routine with a boiler/PI pressure if 1-1.2 bar would be 16g coffee, lever down and wait probably 8-10 seconds, and then raise the lever. With the pre-infusion I would be aiming to see the coffee appear underneath the basket but not actually forming into drips.


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## 4085 (Nov 23, 2012)

Just a quick update. Patrick will hopefully expand further. We stripped my L1 yesterday and found that the existing cafelat seals had small amounts of build up of what was probably great, on the outside edge of the seals where they would rub against the piston chamber. This was obviously the reason why I was getting slipping of the lever. Now, I am not saying that there is anything wrong with the cafelat seals, in design or size. I can say that the red seals came off easily and once fitted with the new Londinium seals, all my ills have been sorted and no slipping and the bite point is back to what I would hope.

I would have fitted the over sized cafelat seals that Paul suggested he would send me, but unfortunately they never arrived, so I could not test them out to see if they cured my problem.


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## The Systemic Kid (Nov 23, 2012)

As David said, when we inspected the Cafelat seals, there were deposits of Loxeal grease on the outer surface of each seal. Never seen this before. Not surprising, therefore, that the lever was biting so high up as the seals' efficiency was compromised. With the Londinium seals fitted, bite point was where it should be.


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## Thecatlinux (Mar 10, 2014)

Just sent you a mail

looks like you've got it sorted , just seen the video you posted , that's not right .

like I said in the mail see if you can find the video of Patrick changing the seals on the forum day (same machine )

hope you're all keeping well

R


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## 9719 (Mar 29, 2015)

This the video?


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## Thecatlinux (Mar 10, 2014)

Yup


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