"Understand different tyre tread patterns"
"Michelin Tyres Aberdeen, Tyres Aberdeen (650 Words)"
[ "Understand different tyre tread patterns;There is a good chance that the only tyre treads you'veever seen are those of agricultural tractor tyres, which tend to be ratherlarge and coarsely spaced. These were designed for use on soft surfaces such asmud or snow. The tread patterns shown above cover a wide range of sizes anddesigns, all made by Michelin - the largest is from a semi-trailer tyreMichelin TyresAberdeen highly successful radial car tyre was launched in 1946, and itfeatured grooves along the sides known as " zig-zag grooves ". Thefirst pattern used comprised four straight sections with alternating straightand diagonal sections. This gave high traction in wet conditions but poorhydroplaning resistance, despite the sipes. The circumferential grooves aredesigned to channel water away from the contact patch during acceleration,reducing hydroplaningHydroplaningis removed by the step pattern shown at the bottom right - this was introducedin 1961 onto truck tyres and then into car tyres in 1962. It consists ofalternating straight sections with tread blocks that have a triangularappearance when viewed sideways, i.e. they slope downwards towards the outerrim of the tyre to provide solid lateral support when cornering on wet roads.They are arranged so that there are no continuous lines between them or theirsupporting edges to disrupt any standing water they might roll rather thanrideThe meshed pattern was first used on off-road tyres foragricultural tractors and earth moving equipmentPATTERN INNOVATIONS:Over time, Michelin has developed new patterns to meetspecific customer requirements, e.g. the tall knobs on extreme off-road treadsprotect against punctures at high speed or heavy loads. In contrast, sandtracks with extra-wide grooves provide good traction over soft dunes whilstminimising their weightThe large pattern shown above was designed to improvegrip on dunes in Africa by increasing the contact area, which reduces tyredeflection - this helps reduce vibration and maintain steering control throughintense sand conditions. Unusually, the sidewalls are purposefully left blank,so they don't trap sand grains under high pressureTYRE TREAD PATTERNS:In the 1930s, Pirelli patented a zig-zag tread patternthat worked in the opposite way to the Michelin design - it was designed tospread water over a wider area rather than compressing it into channels alongwhich it could be channelled away from the contact patch. This also reduceshydroplaning and increases traction in wet conditions. The apex or high pointof each tread block is at its centre. When deflected by external forces, theyprovide lateral stability to avoid excessive lean angles during corneringThis pattern has been used on tyres for high-performancecars since 1950, though initially only in much smaller sizes due to limitationsin tyre construction techniques. The pattern was first used on a Formula 1 carin 1967 and won the race, which marked a significant point for Tyres technology reignitinginterest in wet conditions performance after decades of focus on dry weatherperformanceGiven that the tyres are not required to provide solidlateral support or channel water away from the contact patch as they go aroundcorners, their tread blocks can be very large relative to those under hardcornering loads - this increases traction through high traction coefficient(the ratio of grip between tyre and road). The zig-zag pattern also reducesvibration by maximising weight distribution across a wider area rather thanconcentrating it at points because of the more significant tread block edges.However, these larger tread blocks increase rolling resistance (energy used todeform the tread blocks) and therefore reduce fuel economyA more modern approach to achieving good wet weather gripis shown in the pattern below, which does not rely on large tread block edgesbut slanted grooves designed to work with water-repellent rubber compounds. Byusing more minor grooves that are closer together, it's possible to improvetraction whilst minimising their depth, so they have less impact on rollingresistance - this has become possible since the development of computermodelling techniques in the 1990s allowed engineers to understand better howtyres behave when deflected by external forces under high speed drivingconditions.The key benefit of V-shaped tyre groves is theirability to reroute water away from the contact patch as the tyre rotatesThe pattern of 'V-shaped grooves on anasymmetric tyre for a Formula 1 car. Pirelli and Goodyear both use similar waysto speed up their wet weather tyre warm-up by reducing heat loss through treadblock edges which reduce thermal conductivity - reducing the time needed fortyres Aberdeen to reach optimum temperature before hard cornering." ]