Right, the tensioner works by having a bit of plate bent into an L shape, one end has a hole big enough for the funbolt to fit through, this end is then clamped between the frame and the axle, the other end which is at 90degrees to the bit which is clamped has a sloted hole allowing adjustment for the spring steel, the spring steel is then bolted to the slot so that it point down, becuase it is spring steel it will always (few exceptions) return to its original shape, so it is then bent up and placed above the chain, hence pushing down......... It is had to explain. Adam