Index
- Introduction
- Fitting of Professional chains to tyres
- Reversing and turning snow chains Professional
- Maintenance of snow chains Professional
- Repairing snow chains Professional
Introduction
König Professional chains are among your best allies for winter transport and road maintenance services: The technology developed by König over the years has resulted in ever stronger and more durable products.
But don't forget that Professional snow chains also need your care to ensure that they last as long as possible.
In this article we are going to analyse which actions can bring your professional chains to their maximum strength and durability.
Fitting of Professional chains to tyres
If the Consumer chain is a product that is not used continuously on a vehicle that is mainly characterised by the restriction of space in the wheel arches, the Professional chain follows a logic of its own.
The vehicles for which König Professional chains are intended are characterised by normally clawed tyres with a very steep shoulder and most vehicles do not have any wheel arch limitations. Therefore both the tyres and the vehicles themselves are very different from the target vehicles of the consumer chains.
As with the consumer segment, it is important that Professional chains are fitted and checked before use to ensure that the fit on the specific tyre is guaranteed.
However, the reasons are different.
Let's imagine a clawed tyre on which we are going to install a Professional chain. During fitting and subsequent tensioning, the chain will copy the tyre to wrap around it as much as possible. Therefore, if the tyre tread has marked protrusions (e.g. the cusps of a farm tyre), an over-tensioned chain will tend to clamp completely on the tyre, eliminating the movement of the links on the tread. At this point the protrusions will always force the same chain links to work against the ground.
The result is that the links on the cusps will tend to wear very quickly (they always work with each turn of the wheel), whereas the other links will show no signs of wear. Uneven wear of a chain should be avoided as much as possible: worn links will tend to break before the others and will require repairs to continue working.
This confirms that over-tensioning the Professional snow chain shortens its service life and increases the frequency of maintenance.
For this reason, it is important to carry out the fitting test to check whether the chain fits the tyre correctly before it is actually used. If you start working with a chain that is too tight, it will not have a chance to move later and will tend to last less.
Experienced Professional chain users in Italy always recommend fitting the chain "with the belly". The belly defines the free space between the chain and the tyre which indicates a correct tensioning procedure.
Leaving the "belly" to the chain brings two main advantages:
- Performance: the belly causes the chain to drop to the ground before the tyre touches the ground, significantly increasing the contact surface, providing more links in contact with the ground;
- Durability: the belly guarantees a certain independence of movement between the wheel and chain, ensuring that the links can move and that it is not just a few links that work in contact with the ground.
Reversing and turning snow chains Professional
Let's start with a question. Why do Professional snow chains have to be turned or reversed from time to time?
Imagine a vehicle travelling on the road with a chain installed on the wheel. The contact between the chain and the ground occurs at the front of the wheel when travelling forward, and at the rear of the wheel when travelling backwards.
Given that the vast majority of travel is carried out travelling forwards, the chain will tend to follow that particular angle of link wear.
This angle is most visually appreciable on chains with thick wire or enriched link configurations (ice-breaker reinforcement and/or welded anti-wear bar), but is present on all chains that have travelled mainly in one direction of travel.
Again, if we do not change the direction of rotation of the chains, wear will exceed the maximum safe limit.
This is why it is important, after travelling a few kilometres and checking the wear condition of the tread links, to swap the chains on the wheels: the chain fitted on the front wheel on the driver's side must be fitted on the passenger's side and vice versa.
Let us see together how to turn the chains:
A. Snow chains with single and/or reinforced links
The chain mounted on the driver's side wheel (A) must be fitted to the passenger side wheel (B) and vice versa, by rotating the chain along the longitudinal axis as in the picture.
B. Chains with ice-breaker reinforcements and welded wear bars
The chain fitted to the driver's side wheel (A) must be fitted to the passenger's side wheel (B) and vice versa, reversing the direction of rotation and contact of the chain as in the image.
In this way we stop the wear in one direction and start working the chain in the opposite direction. In this way, wear will tend to be distributed evenly over the whole chain.
Professional snow chains are also reversible. In the sense that they can be used on both sides.
Each chain has two sides: one is in contact with the ground, the other is in contact with the tyre. During road use, the side that is in contact with the ground will tend to wear more than the side that is in contact with the tyre.
Then, when one side of the chain starts to show signs of wear, we can turn the chain and use it on the side that has been in contact with the tyre until now.
In fact, once the wear of the link is uniform and comes close to 30% of the side of the chain that is in contact with the ground, it will be the ideal moment to reverse the chains without changing wheels: the side of the chain that was previously in contact with the tyre will be in contact with the ground and will be able to offer its own volume of wear.
As mentioned above, the reversing and turning over of Professional snow chains is a regular routine that every user should take into account.
Maintenance of snow chains Professional
When you have finished your work session and are preparing to remove the Professional chain from your vehicle, please check it once it is mounted on the wheel. This will help you determine whether there are any points on the chain that are subject to excessive wear or are damaged. Doing this check while the chain is still fitted highlights at a macroscopic level some of the work that may need to be done.
Once dismounted, please wash the chain to remove any dirt and chemical residues that may remain on the chain and affect its protective surface treatment.
Repairing snow chains Professional
If your chain is in need of repair, please use only original spare parts supplied by König. We ask you to consider that spare parts are temporary solutions to repair a damaged chain and finish the work session.
Because the spare parts have all the dimensional characteristics of the original component, they do not undergo the exact same treatment for emergency installation. The classic example of this is the open links, which are supplied as press-on parts, without welding and therefore cannot replace the original chain links in terms of strength and durability.
Welding on worn chains
We strongly advise against the use of welded-on materials on snow chains. Occasionally, some users find themselves welding metal elements over the links of worn chains in order to restore some wear volume to the chain.
Unfortunately, this process only makes the chain more fragile and less durable.
In fact, König chains are subjected to a carburizing treatment of the tread in order to achieve a higher hardness and consequently a higher wear resistance. Depending on the model, Professional chains can undergo carburizing treatment of the tread (truck chains) or of the whole chain (snowplough chains).
In König's production plants, this process is regarded as a high value-added activity and one of the crucial points in the production of a quality chain.
This process involves heating the chain to high temperatures (material- and application-specific temperatures and cycles), followed by a thermal shock and subsequent second heating to eliminate the stresses created during the process.
In short, we are talking about a controlled process with established parameters that ensures the chain has the right balance between tensile strength and wear resistance.
The manual welding operation subjects a chain (which has already been treated) to new overheating which upsets the balance achieved at material level. This may make the chain more fragile and, contrary to expectations, may shorten its life.
For any further info, do not eshitate to contact us at Costumer Service