TESTING ENDURO TYRES WITH METZELER
How do you go about developing and testing enduro tyres? Metzeler invited Rust Sports to Sicily for a trail ride to see how it’s done… (Originally published in Feb 2012)
After two days of trail riding and having covered almost 200 miles we’d eventually reached the final summit of our tour. At 1500m above sea level, from here on it would literally be downhill all the way home. With Mount Etna smouldering away in the distance, lava trails and mountain tracks behind us, and a rapidly lowering sun readying itself to dip below the horizon, we stopped to take in the most picturesque of views. Wow, what a way to earn your living I thought to myself, test riding bikes here!
Over to my left was Salvo, one of my riding companions for the past two days. ‘I think you’ve got one of the best jobs in the world’, I remark as we take in what’s been two unforgettable days of trail riding.
‘It’s pretty good,’ he answers with a smile. ‘I could think of many worse ways to earn a living!’
Sicilian born and bred, Salvo has been riding the very same trails I’ve just been enjoying for over 40 years and now, as head of the testing department for Metzeler tyres, he’s one of the lucky few that has been able to turn his passion into his livelihood. His job has led him to many different places across the globe but for him, Sicily will always be one of the very best places in the world to ride off-road. And I can’t say I disagree.
Now I’ll have to admit that before this trip, my knowledge of Sicily was pretty sketchy. I knew it was a triangular-shaped island jutting out off the southerly coastline of Italy. Its volcano, Mount Etna is a classic volcano-shape and has been active for thousands of years. Oh and I knew that in years gone by it was largely controlled by the Mafia. Or at least that’s what I was led to believe. What I didn’t know was that five million people call Sicily home and that it has long been the main off-road testing grounds of the Metzeler tyre corporation.
Founded in Germany in 1863, Metzeler was completely destroyed during World War II. Since then they have slowly rebuilt the company and continued to grow over the years. In 1979 they decided to focus solely on producing motorcycle tyres and then in the mid Eighties they were acquired by multi-national corporation Pirelli. So Pirelli and Metzeler are actually part of the same company – though both operate independently and forge their own identity manufacturing both leisure and competition motorcycle tyres. Metzeler’s 6-Days Extreme tyre holds 17 Enduro World Championships, and has been OE equipment on KTMs for a number of years.
But why choose Sicily as an R&D base? Why chose somewhere so far off the beaten track to spend countless hours developing tyres? Well, that’s what I was here to find out!
Firstly, being one of the most southerly points in Europe the island enjoys year-long sunshine, only dropping to an average of 10°C during the deepest darkest winter months. With conditions like that to test in, Metzeler are able to spend more time ‘out in the field’ developing their products. Don’t get me wrong though, I was told it can rain here too, and when it does it usually pours, allowing them to test out wet weather grip.
However, the most important reason for the location is the landscape. Mud, sand, stones, gravel and even lava rock are all at their disposal in one convenient location, while for road testing they have mile after mile of twisty mountain roads to contend with. In the space of a day you can trail ride from deep sandy beaches that intersperse the busy seaside towns to isolated, uninhabited mountain-top tracks, and back again. With terrain like this at your disposal, it seems a logical place to be.
Our journey would start from the small coastal port of Riposto. Riding down a short stretch of asphalt road before dipping under a bridge it leads us to a rocky river bed that we follow upstream for a couple of miles before heading out towards the mountains. Minutes later we are treated to the day’s first tricky hill climb – a dusty and slightly exposed rocky single-track that criss-crosses its way up the side of a vineyard.
As I sat and watched my guide disappear out of sight, I initially began to regret laying claim to the shiny new KTM 500EXC that had awaited us earlier that morning. But clicking second gear, the big beast made light work of the climb, without any hesitation too.
From the top of the climb we followed a gravel road that changed between different surfaces every couple of miles. Hard-pack to begin with, it suddenly switched to loose, stony ground that was washed-out in places (scary). Next the track became a muddy trail that had been baked hard by the autumn sun. We carried on a steady pace for many miles, crossing track after track as we rode through a mixture of pastures, forestry paths and stony ground before our pace suddenly slowed as the size of the rocks increased.
Large stones and boulders led us into a broad riverbed with only one way across. It was the type of challenge that wouldn’t have looked out of place at Erzberg! After a bit of line spotting we pulled and dragged ourselves across, and having spent the better part of a long morning in the saddle it was time to be fed – Italian style.
Normally trail riding and eating isn’t something that goes hand in hand in my world. When I’m getting ready to hit the mountains, sandwiches are the last thing on my mind. Usually, when hunger hits I end up searching around in my tool bag for a crusty old Twix, only to find the wrapper stained with oil. Luckily, this time I was in good hands – Italians like their food, and plenty of it too.
At a dirt track crossroads in the middle of nowhere a feast was laid on for us – bread, salads, cold meats, olives and an almost endless supply of different types of cheeses restocked our stomachs. Sitting down to the picnic table for a well-earned rest it also offered the opportunity to relive the morning’s adventure. Through a mix of Italian, French, German and English, combined with a generous use of universal sign language, we all laughed and joked about the near misses and experiences we’d all endured throughout the morning. Although we came from many different places, we were united as one – one group of passionate trail and enduro riders.
Leaving the dinner table was hard. With a stomach full of food and a blazing sun overhead I would have happily whiled away the afternoon there. But we were here to ride the terrain and experience what it was like as a tyre tester so it was time to swich bikes and try out the 300EXC.
Carrying on from where we’d left off, we crossed many more mountain paths all the while steadily climbing until the landscape changed once again. We were now entering lava territory. Remains from the last eruption lay scattered all around us. Black mounds of twisted volcanic rock decorated our surroundings as we rode along a well-beaten path that led us through the lava valley.
There was little vegetation to be found as the once burning rock had killed off everything in its path. Only the odd scarred tree remained. The loose rock danced about underneath our wheels and was tricky enough to catch out the unwary. Soon the valley opened up again and we began the final stretch towards our bed for the night. With bodies aching and tired we were all happy it had been an enjoyable and eventful day in the saddle.
The following day brought more of the same, but on different trails. Pounding out mile after mile it seemed an even bigger treat than on the first day to be enjoying saddle time in ‘complete isolation’. For the most part, the mountaintops of Sicily seem to have changed little over time and hark back to a period when life was basic. Occasionally we passed a shepherds hut with no power and no running water and there was a real sense of freedom as we wandered over the Sicilian mountains, free from the hassles of everyday life. It was just us and our bikes, detached from the rest of the world.
But little by little suburbia began to close in again. First came the start of a tarmac road, followed by farmland, houses and finally a town. Traffic lights, busy streets and a sense of urgency returned. Stopping off at a little street-side cafe we parked our bikes and sat outside chatting about our experience over a cup of strong Italian coffee while traffic streamed past.
We talked about the trail, about what each one of us had seen along the way. We debated which bike was the best of the bunch and why our own personal favourites worked best over the trails we’d just ridden. We compared the vast array of terrain we’d ridden and offered thoughts on how it reminded us of different parts of the world we’d been to before.
I realised too about what Salvo had said at the start of our two-day adventure – that Sicily really did offer everything needed for testing off-road tyres. Sicily is an island that really has it all. With a maze of paths to follow in any direction there’s a seemingly limitless amount of trails to pursue. Even if our trip had only been a relatively whistle-stop tour of a small part of the island, what we’d seen was amazing. We had ridden on yellow dirt in the west and black dirt in the east. To the north and south there was more to discover, but reluctantly I realised that would have to wait for another day.
How do you test an enduro tyre?
There are two main areas involved in tyre testing. The first is mileage and resistance testing. This is basically conducting many miles of testing to evaluate the life and wear patterns of the tyre itself. Tyres are tested to destruction! The second is the behaviour of the tyre under certain conditions. Using a strict methodology developed over the years to analyse the complete behaviour of the tyre in many different types of terrain. All this information is then relayed directly back to the R&D department located at Pirelli’s headquarters in Milan.
In total there are 25 people directly working in Metzeler’s testing department. Last year they they conducted 4500 tests and covered approximately one million kilometres of general testing that covers both road and off-road use.
Metzeler: ‘We have a big passion for enduro and competition. We go racing to be competitive and to try to win but we also involve the race teams with the development of the product. During the development process our test riders can only tell us so much, which is why we turn to some of the world’s best riders to get feedback from them under some of the most extreme race conditions possible. Once we get approval from them we know then that it is good enough for our customers to use.
RUST: The 6-Days Extreme was launched back in 2005, what changes has it undergone since then?
Metzeler: ‘We are constantly fine-tuning the compound of the tyre to improve the tearing-resistance of the knobbles, and improve both the life and mileage capabilities of the 6-Days Extreme. Granted these aspects are not always visible to the eye, such as different chemical and production process, but they are the ones that are crucial to its success.
RUST: What tyre developments can we expect to see in future?
Metzeler: ‘As always we are strongly focused on the continuous development of products by trying to anticipate the needs that the advances in motorcycling technology will bring. We are currently involved in some interesting projects that are looking into the effects that wireless throttle and traction control systems have on the behaviour of off-road tyres and motorcycles. Next year we will also work closely on a project with a university to develop a tyre for electric off-road bikes. We will look to see if the use of electric motors will require a new tyre design, the redistribution of knobbles and how to maintain optimum traction. We want to be ready for any future changes!
Enduro has been part of our heritage since 1935 and is something we are passionate about. Staying focused on this helps us maintain our company’s original ethos of being a people’s tyre – producing tyres used by both hobby and professional riders.