In recent years, all major forage wagon manufacturers have brought higher capacity machines to market, capable of chopping grass to lengths of 35mm and shorter.

The availability of more horsepower within the average contractor fleet and at farm level combined with a transition to multi-cut silage systems sees forage wagons arguably more relevant than ever.

We recently had the opportunity to spend some time with the latest generation RX 370 GL model from Krone lifting a crop of second cut silage, a 37m3 machine capable of chopping grass to 28mm.

Background

The RX range is Krone’s premier offering within the mid-sized class and sits above the MX series, with which it happens to share the same load capacities.

The RX range has a trio of models to offer: RX 330 (33m3), RX 370 (37m3) and the RX 400 (40m3), each offered in GL and GD variants. GL models feature the standard rear door while GD models are equipped with discharge rollers which prove more common across mainland Europe.

While there is crossover between the MX and RX series, there are a number of differences.

For the 2024 season, Krone introduced its current generation RX and larger ZX models. This included the new OptiGrass 28 and 37 chopping units, equipped with 40 and 54 knives. The former is capable of chopping to 37mm and the latter chopping to 28mm.

There was also a reshuffling of transport capacities. The largest RX 430 was dropped in favour of a new smaller capacity machine, the RX 330. Meanwhile, the slightly larger capacity RX 370 replaced the RX 360 and the RX 400 picked up the mantle as the series flagship.

In comparison to the MX, the RX is a wider-bodied range with a wider pickup and more knives as already stated. It is also equipped with heavier duty floor chains and built to accommodate the larger capacity pickup/chopping unit and heavier volumes of grass as a result of the shorter chop.

Pickup

Straight up, the pickup and chopping system was single-handedly one of our favourite features of the RX 370 GL model we had out on test.

The RX series is equipped with a camless pickup measuring 2.12m, which is 320mm wider than the pickup offered on the MX series. Having reviewed the MX 370 back in 2020, the additional width was definitely welcomed when navigating headlands and wider swaths.

The camless pickup is driven via an integrated hydraulic motor which in turn has allowed it to be that little bit wider.

We found the pickup’s hydraulic drive design to offer a number of benefits, one of which was that it automatically engages and disengages as the pickup is lowered and raised, reducing wear.

The second major benefit we noticed was the pickup’s speed control system. When in automatic mode, the pickup speed adjusts in relation to the tractor’s forward speed. However, this feature can be manually set if required.

Krone believes that not having a traditional sprocket drive allows the pickup’s pivoting range to increase and therefore follow ground contours better, which we would tend to agree with.

The pickup reel is equipped with 6.5mm tines which have been arranged in a ‘W’ configuration. Visibility of the pickup from the operator seat was very good and to a large degree unhindered by the drawbar.

OptiGrass chopping system

The new OptiGrass chopping system is available in two versions – OptiGrass 37 with 40 knives and offering a chop length of 37mm or the OptiGrass 28, with 54 knives which is capable of a chop length as short as 28mm.

Our test machine was equipped with the latter which in less than a minute can be lowered and swung out to the side of the machine for maintenance.

Central blade groups allow the full set of 54 knives to be engaged or a half set of 27, meaning one group of up to 27 can be worked until dull and then alternated with the second group of up to 27 fresh blades.

Central to the new chopping system is the integral rotor, which increases crop flow in the outer areas of the rotor.

This is done via the 22cm wide auger bodies at each end of the rotor which convey grass from the outer ends of the pickup evenly towards the centre of the rotor for chopping.

Because the crop is compacted across the entire rotor, there is a more consistent chop and consistent wear across the full knife bank. Each knife is individually spring protected so that it can retract in the event of encountering a foreign object.

Krone’s SplitCut system is designed to stop uncut grass from entering the body of the machine.

The system sees the crop flow split as it passes the knives.

Crop is then fed over the tines back to the front where two deflector plates guide the crop to the middle of the rotor where it is cut and then fed into the machine.

Krone has modified its rotor tines which now have off-centre tips to provide a better shearing action and prevent mushing of the crop.

The chopping unit hydraulically lowers from the cab or via the control panel at ground level in the event that a blockage needs to pass through.

Driveline

In the RX range, the driveline has been simplified with the added benefit of reduced maintenance. The rotor is driven via planetary gearbox and a large PowerBelt.

Between this and the hydraulic drive pickup, both chains and sprockets have been completely eliminated.

Krone claims that the spring-tensioned PowerBelt transmits in the region of 25% higher PTO rpm compared to the previous generation.

Also new are the two interchangeable pulleys. These pulleys can be swapped to adjust processing speed, allowing the wagon to adapt to varying conditions while still ensuring the space behind the rotor is always loaded to capacity. Overall, this maintenance-free approach performed exceptionally well.

Chassis

The RX runs on a tandem axle that is configured to distribute weight uniformly across all wheels for stability while helping reduce soil compaction.

The optional hydraulic compensation system works to distribute the wagon’s weight depending on the terrain. Having operated the wagon on side slopes and in a range of dips and hollows, its stability was impressive for what is a rather high machine. Our test machine was equipped with 800/45 R26.5 tyres, however larger 30.5in rims can be optionally fitted.

Another hugely impressive feature that was optioned on our machine was the new contactless electronic forced rear steering axle.

This system works 100% of the time and doesn’t need to be locked in place during transport. There is nothing to connect, no push rods found with manually forced steering systems. The clever system uses a yaw sensor positioned on the front of the axle frame which records the rotational forces of the wagon. Then the hydraulic system and steering cylinder use the sensor signal to determine the way in which the rear axle needs to turn and does so.

After reversing in a figure-of-eight and many different manoeuvres to try and fool the system, it wasn’t happening which left us pleasantly surprised, responding exactly how and when it should every time.

What’s more, the operator can intervene and manually steer the axle through the Isobus screen if in a tricky scenario where needed – e.g. on side slopes.

However, we found the RX 370 to maintain its track perfectly well on side slopes without intervention. Once familiar with how the rear end reacted upon exiting field gaps, this system left the wagon seriously manoeuvrable given its size and length of 9.29m.

The articulated drawbar is equipped with height control and suspension for operator comfort which we found over the course of the day to also work well.

Performance

During our time spent with the RX 370 GL we drove it with a Fendt 720 Vario which was churning out in the region of 215hp.

Although Krone recommends a minimum power requirement of 175hp, it’s a case of ‘the more the merrier’ if a good forward speed is to be achieved. For a relatively large wagon, the Fendt 720 handled it much better than expected taking into account a heavy crop and a mix of hilly meadows.

More horsepower, would have allowed us to really push the wagon to its limits in terms of throughput. Having lifted 40 acres of leafy, sugary damp grass, we found ourselves dealing with one blockage, which was a relatively straightforward process to resolve.

This involved dropping the knife bank, raising the drawbar and reengaging the PTO which automatically takes the blockage through into the body before reversing all these steps to resume lifting.

We controlled the wagon via the Fendt’s Isobus which will likely be the chosen system for most. However, Krone offers the CCI 800 and 1200 terminals alongside the compact DS 500 terminal.

All the screens (loading, transport and unloading) are well laid out. All processes can be operated in automatic mode or in manual mode depending on operator preference.

The only slight modification we would make to the screens would be to make the loading, transport and unloading screens more distinguishable. The new visual fill level indicator proved accurate.

Now common on wagons of such size, the automatic folding front headboard proves a super job extending carrying capacity by over 4m3 and transferring weight on to the drawbar for optimum tractor traction.

The entire unloading process generally took just over one minute from the point of opening the rear door to closing it, which was impressive given the quantity of grass to be discharged.

Our verdict

Having spent some time with an MX 370 five years ago vs the latest RX 370 more recently, we were well impressed on a number of fronts.

Firstly, the wider pickup is a real comfort and requires much less precision on the headland swaths to avoid blockage etc.

The hydraulic pickup and OptiGrass chopping system is one of the major wins for Krone, we feel that it leaves crop flow into the knife bank much smoother.

We felt that the new rotor design with outer augers left a much more even infeed of grass across the entire rotor width and resulted in more evenly filled loads.

This combined with chop consistency and the ability to chop to 28mm are real selling points which will likely attract a number of potential customers to the RX range over the MX.

The hydraulic pickup and lack of drive chains leaves the wagon exceptionally smooth running and leaves maintenance to a minimum, which again is a major positive.

The contactless electronic forced rear steering we felt is a must regardless of the fact it is an optional extra.

As is to be expected given the size, weight and the fact there is a total of 54 knives, it is a machine that would require in excess of 250hp powering it in order to get the most out of it.

Krone has pretty much nailed it with the latest RX series, rectifying all the areas we previously felt needed to be addressed and is a real market contender within its class.