Low friction concept

Our low friction concept comprises five separate innovations and solutions, each carefully designed to maximize production, optimize
fuel and energy consumption, and drastically reduce maintenance costs. Together, these five solutions provide an unbeatable combination
that allows SP to offer heads with totally unique properties and advantages that maximize your profitability.
Our low friction concept provides you with a highly productive and easily operated head, whether used for thinning, heavy final
felling, or harvesting hard wood. The unique feed roller mounts ensure an agile, narrow head that makes light work of harvesting even
in dense stands without unnecessary wear on the head or damage to standing trees. Parallel to this, when harvesting large-diameter
trees, the rollers provide maximum carrying capacity, able to handle even the heaviest of stems effortlessly, ensuring efficient harvesting
and maximum profitability.
Moreover, SP heads can be mounted on all carriers, regardless of brand, and without the need to replace or modify the machine’s
existing control and measuring system.

Five innovations for maximum efficiency:

Knife Design

The delimbing knives are cast in high-strength steel and equipped with long cutting edges. This means that the limbs are cut off instead of being broken off. This minimizes friction during delimbing and allows the trunk to be fed through easily.

Proportional pressure

Proportional pressure ensures that the harvester head automatically works at the correct pressure in relation to tree diameter. This means that the friction between the trunk and harvester head is minimized and that the harvester head run at peak efficiency. Individual settings per tree species maximises production further.


LogHold is an evolution of proportional pressure and means that the delimbing knife pressure against the trunk can be reduced, without the risk of the trunk being dropped. If the trunk is about to fall, LogHold regulates the knife pressure so that the trunk is held in the right position. The amount by which the diameter may increase before LogHold takes action is set in the control system. No additional sensors are required.

Proportionally angled feeder rollers

This smart solution means that when the harvester head is fully open, i.e. at maximum tree size, the feed rollers are at their greatest angle and provide maximum carrying force against the trunk. As the feed rollers carry the trunk, the pressure on the delimbing knives can be reduced, which means less friction and the harvester head can feed the trunk through quickly and easily.


Optimal hydraulics

mean that pressure drops are minimized by means of the size and design of each hydraulic component, such as the motors, valve blocks, couplings, and hoses. This generates high energy efficiency and the lowest possible fuel consumption per cubic meter timber harvested, with power, force, and productivity maximized during feeding, delimbing, and cutting. Due to the fact that the heads in SP’s low friction concept only have two feed roller motors, the number of hoses, couplings, and bends can be significantly reduced, which also results in minimal hydraulic losses. The low pressure drops also reduce heat generation in the hydraulic system, which increases the service life of many machine components due to less wear and lower maintenance needs.

The advantages of our low friction concept