GMD 1023 F front-mounted disc mowers

The new GMD 3123 F front mower with discs is designed for farms looking for a lighter weight machine for tractors from 80-90 hp. Its compact design and reduced weight make it the ideal mower for flat and hilly regions.
It is equipped with the OPTIDISC ELITE cutter bar and its latest upgrades that guarantee a clean cut at all times.
GMD 1023 F at work

Your benefits

A simply great cut!

Variable spacing between discs on the OPTIDISC ELITE cutter bar

OPTIDISC ELITE: incredible performances!

The new OPTIDISC ELITE cutter bar was developed with farmers. Variable spacing between the discs, large overlap zones and the reduced angle of the OPTIDISC cutter bar will provide you with the quality you need. The GMD 3123 F is equipped with this cutter bar and its latest upgrades that guarantee a clean cut at all times. The OPTIDISC ELITE cutter bar includes exclusive features:
  • Spacing is reduced at the point where the discs diverge to increase knife overlap. This results in a clean cut even in light or short grasses. (A)
  • Distance is increased at the point where the discs converge. This makes more space for the crop to pass through which is quickly carried away to the rear so that the mower can do its job undisrupted. (B)
  • The overlap zone is almost doubled resulting in better cutting quality in damp sticky ground (or with mole hills), in heavy and laying crops, and in plant cover harvested at the end of autumn.
  • A smaller pitch angle: this prevents the undulating cut which is typical with close mowing. It also stimulates homogeneous and faster regrowth and makes it easier to adjust the machines that follow.
  • New disc bearings with exclusive shape and attachment which hold the knives firmly in place in the event of impact while granting 360° rotational freedom.
Soil can build up in front of a cutter bar on hilly plots or in wet and sticky conditions, but not with the OPTIDISC ELITE cutter bar! It has specially designed skids to improve gliding and preserve the sward. Another advantage for forage quality, especially in difficult conditions.

They hug the ground!

The front mowing units have to be flexible in order to adapt smoothly to plot variations. They are often subject to extreme conditions too.
The GMD 3123 F disc mower is designed specifically for this purpose. It has pendulum-type articulation integrated with a travel range of +/- 12° so it is capable of contouring uneven ground. Two suspension springs connected to the tractor reduce ground pressure to ensure that the sward is preserved.
Ground pressure adjustment by two powerful springs

Perfectly structured swaths

On plains or hills, specific disc rotation will optimise cutting quality and swath formation. Swath size can range between 1.2m and 1.4m.
Standard swathing discs centre your forage effectively. The swath is delivered between the wheels of the tractor so is not crushed by them.
Swathing discs integrated

Save time and money

The shaft holding the disc shears in the event of a violent impact and protects the gearwheels

Cutter bar extremely reliable and stable

The cutter bar design has been conceived to handle obstacles. With the PROTECTADRIVE safety system, in case of a very violent shock between the disc and an obstacle, the shaft holding the disc shears above the housing thanks to a cleverly dimensioned shear groove. The gearwheels are protected. In less than 15 minutes, the machine is operational again and at a very low repair cost.
The housing attachment is ensured by long screws, passing through the cutter bar. Any risk of housings being ripped off in the event of shock is prevented.
High-end components reinforce the core of the cutter bar:
  • Cutter bar with special double row oblique contact ball bearings.
  • Large diameter gearwheels in high precision forged steel with 3 cogs engaged.
  • Discs with forged and treated cups over the whole surface area.
  • Disc skids in treated steel with the possibility of adding protective lining (attachment via screws).
To increase the machine's service life, rubber mounts are integrated between the cutter bar and the frame. Shocks have less impact on the machine's structure while mowing at high ground speed.

FAST-FIT: 100% safe knife attachment

The GMD 3123 F mower is equipped with the FAST-FIT quick-release knife system, as standard, which provides 3 extra guarantees:
  • A powerful leaf spring provides constant pressure to the knife retainer: it is not restricted.
  • The knife retaining pins are also equipped with a shoulder to provide an additional level of securement.
  • The leaf spring can only be depressed to remove the knife at one point when the knife is centred over the shoe. 
Therefore when the disc is rotating it is not possible for the knife to be released. To minimize costs the knife retention pin can be replaced separately from the leaf spring.
Cutting quality remains excellent owing to the compactness of the cutter bar and the exclusive shape of the blades which rotate as close as possible to the protective skids.
FAST-FIT quick-release knife attachment for quick and safe knife change

Side guards

In order to avoid machine damage when mowing along the edge of the field or next to trees, the flexible outer guard, FLEXPROTECT, can bend and return to shape and save on repair costs. It is deployed easily, no tools required, and can even be controlled remotely from the tractor cab with an optional hydraulic control unit.
FLEXPROTECT side guards

A light, compact mower

GMD 3123 F in combination with a GMD 4010 for a working width of 7.05m

Designed for medium-powered tractors

The GMD 3123 F model is ideal for medium-powered tractors. The proportionate design of the machine makes it extremely robust and stable at work. For higher output, the GMD 3123 F can be used in combination with a rear GMD 8730 unit or any of the GMD LIFT-CONTROL 1011 series.

A light, stable machine

Its lighter weight and reduced overhang put less pressure on the front axle, and this contributes to great ground hugging. A powerful leaf spring stabilises the mower unit perfectly during headland turns and on the road.
GMD 3123 F at work

Easy manoeuvring and good visibility

The transport width of 3.00m makes the machine easier to handle, especially on the road. Optional wing mirrors are available for safer road travel.
Compact for transport and good visibility

GMD 3123 F in combination with a GMD 8730 for a working width of between 8.20 and 8.75m


Technical characteristics

Working width (m)
Transport width (m)
Cutter bar
Number of discs with wear skids
Disc wear skid
Blade attachment
Cutting height range with standard skids (mm)
Gear train protection system
Headland turning position
Average swath width (m)
Setting into transport position
PTO speed (min-1)
Free wheel
Theoretical tractor power requirement (kW/hp)
Required tractor hydraulic connections
Road lights and signalling on front and rear
Approx. weight (kg)
GMD 3123 F-FF
7 of which 2 high cone discs on both ends
2 - as standard
FAST-FIT quick release
35 to 65
PROTECTADRIVE safety system
By springs (as standard) linked to the tractor
Via tractor lift
1.30 - 1.40
3-point - Cat. 2
Manual folding of the FLEXPROTECT side guards (hydraulic as option)
1000 - Direction of rotation seen from the tractor seat: left or right (factory fitted)
Integrated in the side gearbox
32 / 43
Front tractor lift in single acting (or double acting with floating position)
As standard