Working depth
The maximum processing depth provided by the unit. In cultivators with non-replaceable cutters, this parameter is determined primarily by the cutter diameter, in walk-behind tractors designed for active cutters (see below) - by design features (in such models, even high power does not guarantee a large working depth). The most limited indicator in modern walk-behind tractors is
up to 20 cm, and a value
from 21 to 25 cm can be called small. However, often even such capabilities are quite sufficient. A depth of
26 to 30 cm already provides quite extensive capabilities, and the most advanced models are capable of "biting into the ground"
more than 30 cm.
In any case, the optimal processing depth depends on the type and condition of the soil, as well as the crops for which the soil is being prepared; detailed recommendations on this matter can be found in specialized sources. So it does not always make sense to look for a model with maximum depth - especially since such capabilities require high power. It should also be noted that in many units the depth can be adjusted.
Number of blades
The number of cutters that the two-wheel tractor is equipped with. Note that for models with active rototillers (see below), this parameter is not indicated: such attachments are removable, and active rototillers with different performance characteristics can be installed on one unit.
Speaking of quantity, a cutter means a separate "asterisk" of several curved knives installed on the working axis of the unit. The number of such “stars” is selected depending on the processing width that the manufacturer wants to provide: one cutter captures a strip on average from 12 to 18 cm, and several of them are needed for a more or less decent working width.
Reducer
The type of gearbox provided in the design of the two-wheel tractor.
The gearbox is a mechanism for transmitting rotation from the motor shaft to the working shaft; the speed of rotation is reduced, and the tractive effort, respectively, increases. In modern units,
worm,
chain,
gear and
gear-chain gearboxes can be used; here are their main features:
— Worm. Gearboxes based on a worm gear are mainly used in light two-wheel tractors with passive cutters (motor cultivators). With simplicity and low cost, such a gearbox provides a high gear ratio, which makes it possible to achieve good traction at a relatively low engine power. Other advantages of worm gears include compactness, minimum noise level, smooth running and self-braking ability. On the other hand, such gearboxes do not tolerate high loads, which determined the scope of their application.
— Chain. Gearboxes based on a chain drive — two gears connected by a chain (similar to the mechanism used in bicycles). Such gearboxes are somewhat more expensive than worm gears, but they are more reliable and able to work with higher loads. Another advantage lies in the small width of the body, which is especially important for motor cultivators — the gearbox does not limit the depth of processing, since it can be buried in the soil simultaneously with the cutters.
...— Geared. The most advanced type of modern gearboxes. Such mechanisms are highly reliable and durable, they normally endure long-term work at high loads. The downside of these advantages is the high price. Gear reducers are used mainly on professional equipment, for which "endurance" is critical.
— Gear-chain. A compromise option, which, when installed on a motor cultivator, increases its performance (compared to chain and worm), and when installed on a motor block, slightly reduces the cost of the latter.Number of gears
The number of gears provided in a self-propelled cultivator / two-wheel tractor, in other words, the number of travel speeds. There are both the simplest
two-wheel tractors for 1 gear or
2 gears, as well as more advanced ones with
three,
four and even
6 gears. Lower gears are not fast, but they allow you to effectively cope with high loads, and are also better suited for starting from a place; higher ones give low tractive effort, but good speed. Thus, the presence of several gears makes it possible to adjust the operating mode of the unit to the specifics of the situation. The number of gears is also relevant for reverse gear, because there are walk-
behind tractors and cultivators for 1 gear or
more.
Noise level
The maximum noise level produced by the cultivator / two-wheel tractor during operation. A noise of 70 dB is comparable to a very loud conversation, 80 dB to a busy city street, 100 dB to a production shop. The lower the noise level, the more comfortable the use of the unit for the operator himself and the less inconvenience it causes to others.
