Maxxis 3c triple compound mountain technology uses a harder longer lasting base layer and two progressively softer top layers in order to optimise traction and stability maxxis offers three different configurations of their 3c triple compound mountain technology maxx speed maxx terra and maxx grip review please read the review found in a leading mtb cycling magazine 3c maxx terra compound maxx terra is an intermediate compound configuration used in select mountain bike tyres it is softer