The eminent Michelin tire company showed interest in this, providing its Michelin Ivalo 2 dimensions 195 / 65R15. By the way, the French, creating new winter tires, work a lot and seriously with the stud manufacturers.
So, we are in Finland at the polar Test-World training ground, which is a thousand kilometers north of Helsinki. For testing, "Turvanasta" prepared and tested seven sets of identical tires: with one-, two- and three-flange studs of different manufacturers - French Ugigrip, German Sitek and, of course, with their own. Our task is to determine the dependence of the grip properties on the size of the tongue protrusion above the tread and, from our positions, evaluate the strengths and weaknesses of different spikes.
Even in the manufacture of Michelin Ivalo 2 tires, the nests are molded (in cross section they resemble the inverted letter T) to the dimensions of the spikes, so in reality we will have to figure out which of them will behave better in this tire.
The average protrusion is 1.44 mm. Good starting, but acceleration is difficult - they abruptly break into slipping and recover for a long time, while efficiency drops significantly. When braking, ABS starts to work early, there is not enough information. In cornering, the tire responds well to steering wheel overturn, and in understeering, understeer is not so pronounced. It seems as if a steering effect appeared on the rear axle. Four spikes fell out on the left front wheel on the inside.
We carry out exercises according to our “Zarulevsky” method, but with some additions. Acceleration in two versions: using a traction control system and the most effective, braking - with ABS and with wheel lock, finally, an ice circle - on the verge of sliding and with slipping. In addition, we evaluate acceleration, braking control and traditional handling. Rides only on ice, cars - Alfa Romeo 156 Sport Wagon 2.0 JTS.
Weather conditions are the most difficult for winter tires. March in the yard - it should be still cold and snowy. But the air temperature is about zero, the bright sun slightly melt the ice, and in the zone of contact of the wheels with the road, a water film forms, which acts as a lubricant.
Looking ahead, we say that the difference in the coupling properties of the same tires, but with different spikes, reached 10% - sometimes tires from different manufacturers are closer to each other.
And now about what we managed to find out by testing tires with different spikes.
The average protrusion is 1.32 mm. Trolling on tires with such spikes is difficult - they do not like slippage during acceleration and any slippage - both in cornering and in braking. Acceleration is effective only by pulling, on the verge of collapse - when the wheels do not slip at all when braking, like Sitek, ABS starts to chirp early. The reaction to steering the steering wheel is good only in the initial phase, then the car breaks into slipping - it slides for a long time, and the clutch recovery is very tight. In addition, the “reverse” transition - from sliding to rolling is not obvious and poorly understood by the driver. There are no lost spikes.
SINGLE FLANGE SPIKES
The design of single-flange spikes is unpretentious (in the people - "cloves"). Every extra 0.1 mm protruding from the tire improves the grip by 2–4%. But, of course, there are reasonable limits.
An increase in the protrusion is in favor of acceleration, but with braking, not everything is so simple. An increase from 1.44 mm to 1.60, even when using ABS, has virtually no effect (improved grip of less than 1%). But sharply, by 10%, increases the braking distance by use. Not surprisingly, the highly protruding spikes tilt strongly. For the same reason, the lateral coupling properties of the tire on the verge of slipping and steering in a corner are deteriorating. The limit, still providing high grip, is not more than 1.44 mm. But the protrusion of 1.32-1.35 mm allows you to save all the spikes, and at 1.44 mm four out of 440 were lost. The protrusion of 1.60 mm completely led to the loss of 50 spikes. The conclusion is obvious: the optimum is 1.30–1.35 mm.
The average protrusion is 1.60 mm. The most effective overclocking in all modes and even with slipping. Braking is similar to previous tires. In the initial phase of the high-speed turn - a small drift. In tight corners, the car is better controlled by gas than by steering: if you add gas, it starts to turn into a turn. In the discharge and "neutral" gas, understeer is pronounced. But in a circle a car with such tires is trying to break into a skid. Prefers slipping. Most spikes lost: 33 on the left front wheel (22 inside and 11 outside) and 16 on the right front wheel (10 inside and 6 outside). One spike is on the rear right wheel (inner track).
The size of the protrusion should not be increased more than 1.30–1.35 mm, otherwise some coupling properties are reduced and there is a risk of losing the spikes.
+ Ease of manufacture and, as a result, low price; good stability of the protrusion during operation.
- Lack of efficiency with a protrusion of less than 1.3 mm, relatively low durability.
With the same protrusion, two-flange are 1–4% more effective than “studs”. A good example is the two-flange Sitek (with a protrusion of 1.35 mm) with a clear advantage beat the eponymous single-flange analog with a protrusion of 1.45 mm.
The average protrusion is 1.35 mm. Good starting and acceleration. When braking, ABS response is well felt. In a bend, a soft transition in slip. It starts to break very early, but the loss of control over the car occurs later than on tires with other spikes. Because of this, it turned out to be the worst lap time on the verge of slipping. On tires with such spikes, when driving along a winding road and in corners, well-controlled sliding movement is possible. There are no lost spikes. In the front tires, the protrusion of the studs has changed significantly (an increase of almost 0.3 mm).
The two-flange has no pronounced dependence of the coupling properties on the size of the protrusion. In any case, to the extent that were in our tests. For them, an increase of 0.1 mm gives 1–2% efficiency. The design features of the studs (configuration and materials) are more significant here. The maximum protrusion is 1.5-1.6 mm, but it is hardly advisable, since it almost does not affect the adhesion properties. The reasonable limit is 1.30–1.40 mm.
The average protrusion is 1.35 mm. At the moment of starting, it slips, but the further acceleration is pretty confident. Braking as in kit No. 1 - even without ABS it is easy to brake on the verge of wheel lock. Very good response to steering at the initial moment. It reacts worse to a turnaround. Further in the bend - a sharper breakdown of the car and restoration of coupling properties than on tires with other spikes. Turning is more nervous. 3 spikes lost (1 spike on the right front wheel outside, 2 on the front left wheel - 1 outside and 1 inside).
Now about the effect of "growth" on mileage. The loss of the spikes depends not so much on the size of the protrusion, but on their design. With a protrusion of 1.35 mm, all Sitek spikes remained in place, Ugigrip lost four pieces, but Turvanasta with a protrusion of 1.53 mm did not lose a single one. Despite the fact that the set of tires with them ran three times more than the others, he was entrusted with the role of the base for tracking changes in coverage in each exercise.
The stability of the protrusion of two-flange spikes is worse than that of single-flange spikes - they slightly "grow" in the initial period of operation. Optimal in terms of price / quality.
The average protrusion is 1.53 mm. The fastest acceleration on the verge of slipping. When braking, ABS response is very well felt. Effective braking. The corner has very long slides; the car practically does not react to the steering wheel turn. No car skid, only demolition. There is no clear boundary between the transition to sliding and the restoration of coupling properties. Driving in tight corners is uncertain, but in a gentle corner - the highest speed. It is possible to control gas only with small slides and a small slipping of the wheels. There are no lost spikes.
More effective than single flange. The coupling properties and the reliability of the fit are more dependent on the shape and materials than on the size of the protrusion. The preferred protrusion is 1.3-1.4 mm.
+ Higher efficiency, good grip stability, more reliable tire retention.
- “Growth” of the protrusion during operation.
Structurally, the three-flange studs are the most complex and expensive, designed for low-profile tires of powerful cars.
Excellent traction during braking and acceleration (with ABS and ASR) allows you to keep the tires in the initial phase of sliding. The spikes are distinguished by high stability - during the test, their height remained almost unchanged. It is clear that the properties of three-flange to an even greater extent depend on the features of the design and materials. In addition, they are firmly held in the tire and provide the highest stability of coupling properties.
The average protrusion is 1.41 mm. For a good overclocking, a small slip is desirable. It is very difficult to catch her. Braking is like kit No. 3. Best results on tires with these spikes are obtained with electronic slip control systems. When cornering breakdowns and prolonged recovery - the speed is sharply lost. Driving on ice requires a decrease in speed in order to stay on the trajectory. These spikes are best kept in the tire. After testing, there are no spikes and their performance has not changed.
The most difficult to manufacture and, as a result, the most expensive.
+ Keep well in the tire, stable and efficient, especially on the verge of slipping.
- High production complexity, costly, long break-in.
So, we found out that the design features of the studs and their protrusion over the tread significantly affect the coupling properties of winter tires.
A good studded tire is a carefully balanced complex that is easily destroyed by inappropriate studs. For example, cheap single-flange, instead of the provided two-flange, significantly worsen the grip of the tire. Ask who needs this? We explain.
The difference in price of single and double flange studs is 10-15%, and for those who produce studs, these percentages often serve as an additional source of income. And the difference in the price of average tires with various studs is only 0.5–1%. So for the buyer, tires with different spikes are almost the same. That is why most manufacturers of winter tires now take their own studs in their hands or at least control the process. But what about buyers of winter tires? Refine the brand of spikes and measure the size of their protrusion?