New tread compound from Continental

Conti Speedking Supersonic and GP4000S have new compound

Two recently-arrived tyres from Continental feature a new tread compound that will soon be used across a large part of the German manufacturer's cycle tyre range. Promising significant improvements in every key area of tyre performance, the tread compound is named Black Chili and will replace the mix used on all Continental cycle tyres that currently have a black ASC (Activated Silica Compound) tread. Black Chili uses technology developed by the German manufacturer's car racing division. This includes new rubber mixtures, or 'polymer systems', but the most important innovation is in the filler material, which determines the hardness and elasticity of the rubber. Traditionally, carbon soot, which adheres tenaciously to rubber and gives it the familiar black colour, has been the favoured filler.

More recently, powdered silica, which forms a more elastic compound and permits the making of coloured tyres, has become popular. The latest development involves the refinement of carbon particles down to the size range of around 1 nanometre. These are not carbon nanotubes, but their size means that a greater density of filler to rubber can be achieved, thus improving the durability of the compound. At the same time, the smaller particles are better able to move relative to each other, ensuring that the compound is also more elastic and better able to conform to the road surface than that of a tyre filled with larger particles.

Continental says the performance of the new compound has exceeded expectations. It is said to offer a 30% improvement in both grip and rolling resistance over the black ASC compound currently used in Continental's GP4000 clincher. Tread life is also claimed to be increased by around 5% thanks to the greater abrasion resistance of the compound.

RCUK has tried the GP4000S,the 'S' denoting the model with Black Chili compound. Tactile impressions are of a much softer and stickier tread, which indents easily and deeply using a finger nail. On the road, an increase in grip is immediately noticeable in both wet and dry conditions, although it is impossible to verify the 30% figure. The tyre feels fast. However, the claimed 30% applies to the component of rolling resistance due to the tread compound, which is only a part of the resistance of the tyre as a whole. Look for a more detailed tryout on RCUK soon.

Two Conti tyres currently have a Black Chili compound tread. The GP4000 Race road tyre, initially available in 700x23c format, is priced at £34.95. On the off-road side, the Speedking Supersonic comes in 26x2.1 and 26x2.3 sizes and sells for £28.95.