Duotone Silver SeriesThere is also the new combination of a round tube in the front area (holding forces act obliquely downwards, so it is stiffer around here) and the OVAL TAIL SECTION (horizontal sail pull, thus the oval tube is stiffer here). This makes the entire SILVER around 30% stiffer. Together with the hardened front tube, this results in enormous stiffness and durability. We are even prepared to offer a two year unlimited warranty on all SILVER models even on