Offset vs Speed tiller

Dec 05, 2023    Posted by Stewart Knight

In today's world, a comparison is often drawn between speed discs and offset discs. Speed discs have risen in popularity in the last decade as farms and contractors look for ways to cover more area in shorter time frames. But is speed the answer? The simple answer is it depends on what you are trying to achieve. Speed tillers are great for light cultivation, up to a depth of 50mm max or where there is a need to chop up stubble or trash on the surface. Offset discs are great for primary cultivation when a complete weed cut out or when a greater depth of loose tilth is required. Whilst saying this both machines have a place in the Australian cultivation scene, as they both complement each other. 

Speed disc

Speed discs as the name suggests rely on speed to achieve soil penetration due to the aggressive angle the discs are positioned at. Travelling at speeds under 8-9 km/h with a speed tiller causes the disc to simply chisel at the soil rather than cutting it. The other issue here is that if sufficient speed is not achieved there simply isn't enough volume of soil thrown in the machine to properly fine the tilth down.

Speed discs typically have individual floating disc plate units either using a rubber bush mounting or via springs. This is great for clearing trash and floating over rocks at speed without any damage to the machine as each disc unit can operate independently of the one beside it thus keeping the machine level and flowing smoothly. However, this also means that firm ground is skimmed over with no depth achieved. So, if your purpose is to try and achieve a complete weed kill or to move the soil and increase the oxygen level it is simply not the machine for you.

Offset disc

Offset discs have 2 gangs or units of disc plates assembled in a V like formation. This formation pattern means the soil is being cut with the first gang of discs and moved sideways then the second gang comes behind and moves it back to its original position. This movement of soil ensures that every weed is completely cut off and mixed into the soil. Offset discs get their penetrating power from simple weight and rigidly of the frame. With disc plates set in gangs, some manufacturers offer up to 13 plates on one axle and each disc forces the next into the soil. This allows the unit to be operated at the optimum speed to suit the conditions. The main thing to remember with an offset or even a tandem disc is that speed has a direct effect on the amount of soil moved. Pulling an offset disc at high speed in firm conditions may cause it to ride out of the ground.

The place offset discs hold in the cultivation scene, is that of a machine that is capable of cultivating the harshest of soil types to form new paddocks or for chopping in trash in preparation for the next crop. To achieve a complete weed kill on fallow ground while turning up fresh soil to oxygenate it and stimulate growth. When it comes to cost effective low maintenance cultivation an offset disc is the machine of choice.

So which machine is for me?

Both machines complement each other very well and both have their place. If your need is for light cultivation or fast weed control on fallow ground the speed tiller is ideal. In some instances, a seeding box can be fitted in front of the rear roller of the speed tiller which makes for a great option for fast cultivation and sowing of small seeds in one pass. However, when you need a complete weed kill and cutout or to achieve a greater depth of cultivation to move and oxygenate the soil to stimulate plant growth then an offset disc is your first choice. If you need to turn some rough country back into usable soil for cropping or pasture then offset discs are the only machine for you.

Unsure if a speed disc or offset disc is the best unit for you reach out to the Delmade team we are very happy to answer questions you may have. You can also check out our learning centre for more information or click here to submit your question to be answered! Phone 1800 335 623.