The rear-specific 24mm Grand Prix Force is designed for maximum grip, power transfer and excellent wear. The tread pattern and rubber thickness are specific to model, with the Force requiring more tread rubber due to the fact that a high percentage of rider weight is carried by the rear tire. It's front specific counterpart, the Grand Prix Attack, has a smaller casing and less tread. The Attack and Force tires are specifically engineered to provide optimal performance as a front (Attack) and rear (Force) tire combination and Conti refers to these front and rear specific designs as TPS - Tire Positioning System. The 24mm size of the Attack is intended to increase surface area and the tread pattern is optimized for traction and fighting shearing forces at cornering angles found with the more heavily weighted rear wheel. Ideally this is a racing clincher, best used in in events from criterium through time-trial, and triathlon.
The amazing BlackChili tread compound is what makes the complex design truly shine. It features nano-particles that conform to the road enhancing traction and it was optimized for the function of each tire. The compounded properties deliver excellent wear, and as little rolling resistance as possible in a racing clincher that is more than capable of holding in a 45mph corner. Both Attack and Force tires have a single layer Vectran puncture protection strip inserted under the tread for flat protection. Vectran is essentially a protective belt made of super strong and extremely lightweight material. Carrying all this technology is Conti's proven 3 ply/330 tpi casing, which offers great feel and control. The recommended tire pressure range is 110-120 psi.
These tires were designed to be firm, which maximizes the design and rubber compound's capabilities. After taking a few practice corners at speed, you will appreciate this, and realize how much faster you will be able to enter and exit with. Small wear level indicators have been molded into the tread help you monitor tire life. Having the ability to buy this tire design in individual front and rear models opens up many possibilities, and makes it less awkward when you need to replace only one of the set. Given that Conti designed these tires to be complementary, we recommend you run the Attack/Force as a combo, but we know a few riders who prefer to run the Force in the rear with a tire suchs as the Grand Prix 4000S II in the front. It is utlimately your choice, and if you are running newer, wider rims, you have to consider how your tire/rim choices impact performance.