When the portafilter keeps creeping further to the right
The bayonet ring is the ring in the brew group that the portafilter’s lugs lock into. With every shot it holds nine bar against the gasket – and every time you lock in the portafilter and knock it out, it loses a little material. After years you don’t notice this on the ring itself but on the handle: the portafilter has to be turned further and further before it sits.
At some point a new group gasket no longer solves the problem. Then the ring is worn out. That’s normal wear on a machine that pulls hundreds of shots a day – and a ring costs considerably less than a new group.
When it's due
- The portafilter has to be turned well past its usual position before it holds.
- It comes loose under pressure or jumps back a little during a shot.
- Even with a new group gasket, the group no longer seals properly.
- The contact surfaces in the ring are visibly worn, chipped or burred.
- When you insert the portafilter, you can hear and feel it catching and jamming.
At a glance
| Type |
Bayonet ring, locking mechanism for the portafilter |
| Installation position |
In the brew group, under the group head |
| Fits |
La Marzocco. The documentation doesn’t name a single model – the number L109.02 in your service documentation is what counts. |
| Scope of delivery |
One bayonet ring. Gasket, shower screen and screws are not included. |
| Part number |
L109.02, previously L109.01 |
| Version |
Original spare part |
| Brand |
La Marzocco |
| Installation |
Installation by a qualified professional recommended |
Important for installation
The ring sits on the brew group, a pressurised component that gets hotter than 90 degrees during operation. Before any work, the machine is disconnected from the mains, the pressure is released and the group is allowed to cool down. We deliberately do not provide step-by-step instructions for this. And one point that is not up for discussion: a group in which the portafilter can come loose under pressure must be taken out of service immediately – hot coffee grounds are ejected under pressure when that happens.
Who it's for
For high-volume businesses whose group has worn out after years of use, and for service technicians putting a used machine back in order. If you only make espresso now and then, you will usually never need this ring.
What goes with it
For the Linea Mini there is a separate Linea Mini brew group bayonet ring. A new gasket belongs with the replacement – for example the 8 mm group gasket for GS3 and commercial machines or the 9 mm group gasket, old version. You’ll find everything else under La Marzocco accessories and spare parts.
From our workshop in Bern and Zurich: We use a felt-tip pen to mark on the group head where the portafilter sits with a new gasket. Six months later, the distance to this mark immediately shows whether only the gasket has given way or whether the locking mechanism itself is wearing out. That’s our routine, not a manufacturer specification. After the replacement we test the group with a few shots, for example with the Nutty Delight or the Cozy Chocolate, and for milk drinks with the Very Nutty. Find more under Coffee beans.
Returns excluded
Original spare parts are excluded from exchange and return. They are procured specifically for each order and cannot be resold once they have been installed or test-fitted on a machine. So before ordering, check your machine’s model, year of manufacture and serial number – or drop us a quick message and we’ll check the fit together. Your rights in the case of defective goods remain unaffected.
Frequently asked questions
Is this the same ring as for the Linea Mini?
No. The ring for the Linea Mini is a separate item with the number A.3.005. This one has the number L109.02, previously L109.01. The two are not interchangeable.
How can I tell whether the ring or the gasket is to blame?
Fit a new group gasket. If the portafilter then holds in its usual position again, it was the gasket. If it has to be turned further than before, the locking mechanism is worn out.
Is a gasket included?
No, only the ring is supplied. A new group gasket belongs with the replacement and is ordered separately.
Will the ring fit my machine?
The documentation doesn’t name a model, so we won’t guess. The fit is certain if your service documentation lists L109.02 or L109.01 – otherwise send us the serial number.
Can I see the part at your shop?
Yes. At Gerberngasse 44 in Bern and Hagenholzstrasse 50b in Zurich, we’re happy to compare the ring with the one installed in your machine – bring the old part or a photo.
Questions about the fit? Write to us at [email protected]. We deliver across Switzerland and to Liechtenstein in 2-4 working days.
