Sauber can't afford to simply jump in and copy Mercedes' innovative F-duct solution - even assuming it wanted to.The small Swiss team had almost winning race pace at the 2012 Malaysian GP even without the extra straight-line speed that would be provided by a system along the lines of Mercedes' DRS-complementing concept.Despite their complaints about the legality of the system, there is little doubt the big-budget teams will be working frantically to emulate the Mercedes' concept which, to date, has the blessing of the FIA.'BLANK SHEET? TWO MONTHS!According to Germany's Auto Motor und Sport, however, it would be a different story for smaller teams."If we started now with a blank sheet of paper, we would be ready in two months," said Sauber's chief designer Matt Morris, "but it would really add up. We have to ask ourselves whether it's worth it or whether we would be better off chasing lap times with more conventional steps."On the other hand the big teams can handle a development like that in parallel to their normal programmes."Also on the technical front, Auto Motor und Sport reveals that rival teams are closer to getting to the bottom of Red Bull's ever-flexible front wings.After the last day of testing in Barcelona, detailed photographs emerged of Sebastian Vettel's stricken RB8 that appeared to show a sort of torsion bar inside the damaged front wing. The report said the bar could be pre-loaded to pass the FIA's static load tests but then bend at speed.An FIA insider suggested the system, although permitted in private testing, "would not be allowed" in a GP race.