Asphalt VS. Gravel

砂石與柏油路面就像"粉筆和起司"
Gravel and asphalt are like chalk and cheese - but drivers in the FIA World Rally Championship must master both to stand a chance of winning the title .

輪胎的設計與選用還是扮演著最關鍵的角色
Tyres play a key role on both terrains; therefore good tyre design is one of the main components in the fight to create a car really in tune with the road conditions.

碎石路面輪胎設計使用較高海陸比，可以挖開鬆軟的沙石讓輪胎接觸到下層較硬的路面來得到抓地力。為了獲得較好的抓地力，WRC車手必須用更具侵略性的跑法。
Tyres designed for gravel have an open tread pattern that digs through the loose surface to find grip. WRC drivers need to drive more aggressively on gravel so that these can cut through to the solid surface underneath.

在碎石路面，輪胎還必須能吸收來自路面的衝擊及起伏，因此必須要有更厚的胎壁及更強的結構來緩衝這些衝擊。砂石路面輪胎胎高比柏油路面胎來個高，所以要搭配較小的輪圈。
On gravel, tyres also have to absorb bumps and impacts characteristic to the surface; therefore these have to have a deep sidewall and a strong construction to cushion the impact. The gravel tyre is taller than the asphalt one so it is mounted on a smaller wheel.

柏油路面輪胎的目的是要盡可能的使更多的橡膠與路面接觸
Asphalt tyres are designed quite differently. On tarmac the target is to get as much rubber in contact with the surface as possible. For this, the tarmac tyre has to have the least tread possible.

柏油路面比較平坦，所以輪胎設計比砂石胎硬的多來獲得更清晰的路感，並且有更扁的輪胎跟18inch的輪框。
On tarmac, the bumps are much smaller so the tyre has to be built harder to make the World Rally Car's handling feel very direct. These tyres have less of a sidewall and an 18-inch wheel.

輪胎配方的選用也是相當重要。軟胎能提供較好的抓地，硬胎則較
An important factor when selecting compounds is to try to find a compromise between grip and endurance. Softer compounds give a high grip but wear out quickly, while hard compounds offer less grip but last longer.

在雨胎的選擇：較硬的配方較慢熱因而抓地力較差，較軟的配方抓地力較好
In wet conditions, a hard compound tyre does not heat up so much, offering less grip, but softer compounds are more predictable in the rain.

下半季還有八場比賽，四場柏油賽事，四場砂石賽事。輪胎選擇依然主宰著比賽的勝負
The second half of the season has eight rallies left, four of them asphalt and the rest gravel. Choosing the right tyre for the conditions - and then using it correctly to master the surface - could play an important role in the outcome of the championship.
WRC ANALYSIS