Tyre specification can often be overlooked by many when in the search for a suitable tractor. However, tyre choice and maintenance play a pivotal role in minimising soil compaction, increasing fuel economy, increasing operator comfort and helping to reduce overall running costs. It is important to ensure your tyres are in good working order, for both your safety and for your pocket.

To find out more on correct tyre choice and general maintenance, we caught up with Kevin Burke from Kevin Burke Tyres in Galway who offers readers some tips and advice.

Choosing the right tyre

“Most tyre businesses like ourselves will offer three to four different brands of tyres with varying prices. This typically includes a budget, a mid-range and a premium tyre. The person looking to fit new tyres needs to ask themselves what work they will be doing with the tractor and how long they will be keeping it for.”

It is important to remember that the tyres originally fitted to your machine when it was new were selected by the manufacturer and tyre producer, taking into account all aspects of work, size and the power

“Farmers doing 400 to 500 hours each year mostly feeding cattle and doing light work will get away with the middle-of-the-road or a budget-plus tyre. The long-term plan for the tractor should also be considered. Many of these budget-plus tyres will suit a farmer doing 500 hours a year and should last the 4,000 hours over eight years. Will you still have the tractor in eight years’ time? Meanwhile, at the other end, tillage farmers will typically go for higher-end tyres which offer lower ground pressure, minimal compaction and increased traction.”

“It is important to remember that the tyres originally fitted to your machine when it was new were selected by the manufacturer and tyre producer, taking into account all aspects of work, size and the power. Changes to the tyre size, structure, load and speed ratings should not be made without first seeking advice from the vehicle or tyre manufacturer.”

Tyre technology

There are effectively three different tyre categories. These include standard tyres with traditional radial casings, IF (Increased Flexion) tyres and VF (Very high flexion) tyres.

Standard tyres are the most commonly found. Proper use requires constant adjustment of tyre pressure when you change from a field surface to a road surface. IF or VF tyres combine flexibility, technology and solidity. An IF tyre can carry approximately 20% more weight while a VF tyre can carry 40% more weight.

IF and VF tyres are for the more professional user

IF and VF tyres are designed to allow you to carry the same load at higher speed, but at a much lower pressure. This is down to the sidewall design that means you can set your tyre pressures low for fieldwork, while you know they will still perform at high speeds.

Kevin noted: “IF and VF tyres are for the more professional user. Some guys have started using them for slurry application but the uptake is mainly the tillage operators, some of whom are now using tyre inflation and deflation systems while on the move. These tyres can run on as low as 6 PSI versus a typical tyre that can only run as low at 14 PSI (18 PSI recommended). However, this tyre technology is on average 25% more expensive than a standard tyre.”

An IF tyre can carry approx 20% more weight while a VF tyre can carry approx 40% more weight, but this technology is on average 25% more expensive than a standard tyre.

Tyre pressure

Tyre pressure should be checked monthly. Most people only take visual assessments and actually run tyres with too little pressure. Running tyres underinflated causes the rubber to heat. When it heats it will wear very fast. It also increases fuel consumption as power is lost through flexing and increased contact with the ground. Flexing and bouncing adds to the problem of stressing the sidewalls, thus causing damage to the casing. Stability at higher speeds in transport is also reduced.

Overinflated tyres tend to have a reduced surface area in contact with the ground, meaning reduced traction. Hard tyres offer an uncomfortable ride and also lead to a reduced tyre life.

There are tools which enable you to calculate the correct pressure for your specific agricultural tyres. Most manufacturers now offer smartphone apps. The correct pressure will depend on several factors (size, load, speed, soil, etc) to optimise their lifespan. If in doubt about the correct tyre pressure for the type of work being carried out, contact the manufacturer or your tyre dealer.

Maintenance

“A big thing we have seen over the past 10 years is the increasing weight of round bales handled with front-end loaders. This is putting an increased strain on the tractor’s front axle and tyres. The front tyres are only lasting half that of the rear and we even see a lot of rims cracking and axle damage. Many are blaming the longevity of modern tyres, but it’s the overloading of the tractors front-end loaders which is being pushed too hard in most cases.”

“Another issue is tyres wearing to one side. This is largely down to the wheels being forced out of alignment. To help with longevity, farmers doing a lot of loader work need to run the front tyres at the manufacturer’s maximum recommend PSI.”

Tractors should be aligned once per year

“Tractors in Ireland tend to do a lot more road work than tractors in most countries and that’s why more manufacturers are now pushing specifically designed road tyres for tractors. We see a lot of tractors with front axle suspension and weights/implements on the front linkage showing inconsistent wear. Mounting ditches trying to get in and out of tight gaps or even hitting a hole in a field while working will all affect alignment. Tractors should be aligned once per year. It costs around €100 but this is cheap compared to a set of new front tyres. We have even seen tractors only one month old needing to be aligned where they did not have their pre-deliverry inspection done correctly. Lots of the time, we see mechanical issues such as track rod ends or axle issues having a major effect on tyre wear. Incorrect wheel alignment will also have a negative effect on fuel efficiency, particularly when on the road”.

Ratios

“In recent years, we see a lot of farmers and contractors looking to fit wider tyres onto narrow rims. The goal here is to have a square footprint on the ground, increasing the overall surface area. If the rims are too narrow, you will get an egg shape instead. This will have a negative effect and instead lead to irregular wear on the lugs, poor traction, possible sidewall cracking and bead damage.

It will also lead to a difficulty in working at low pressures and won’t offer the same flotation effect. Such tyres won’t last as long and won’t wear evenly as they are not flat on the road. This was the reason we actually started manufacturing rims at our premises in Athenry. Typically speaking, all rims have a tolerance of +/- 50mm. Take a 16in rim fitted with a 480/70 R28 tyre – it can comfortably handle a 420/70 R28 tyre or up to a 540/70 R28 tyre”.

Drive forward 10 revolutions and the reverse back the same. If the correct tyres are fitted, you should return to the exact same spot

“It’s also very important that the tyres fitted on the front and rear of the tractor are in sync for correct operation of the tractor. One fast way to check is to mark the rim and the concrete directly underneath using chalk. Drive forward 10 revolutions and the reverse back the same. If the correct tyres are fitted, you should return to the exact same spot. It is not recommended to combine tyres with different technological norms on the same machine, as it creates an unbalance.”

Used tyres

“Secondhand tyres often appear to be good value but they usually aren’t in the long run. If you take a €5,000 set of tyres which lasts 6,000 hours, that’s a costing of 83c/hour. If you buy a secondhand set of tyres and try a similar costing, taking into account repairs and downtime, you don’t get the same value for money.”

Kevin noted that typically with used tyres there usually tends to have been a problem somewhere and people need to ask themselves why were these tyres taken off in the first place.

“People need to ask themselves why were these tyres taken off in the first place – there usually tends to have been a problem somewhere. Take tyres that were on a hedge-cutting tractor for example.

“If blackthorns get into tyres, you won’t keep them hard. I would also strongly advise against the mixing and matching of used tyres as this will affect operator comfort.

“However, if you do come across a genuine set of used tyres, be sure to check the date of manufacture. This is stamped into every tyre underneath the size. It states the week of manufacture followed by the year. After five or six years tyres tend to dry out, the sunlight leads to the loss of oils in the rubber and they will begin to perish.”