So fast they need the best brakingcosmic pro carbon sl c is the pinnacle of carbon clincher wheels as its both incredibly light and aerodynamic but also because it excels in an area that most of our competitors ignore strength and durability its these qualities that make it ideal for going fast on all terrain whether on the flat or up and down long mountain passesthe problem with carbon clincher rimsheat dissipation its very difficult to combine carbon rims and a high pressure clincher ti