A clamp having a first member, a second member connectable to the first member and a second surface having a first groove and a second groove, each groove for receiving a toothed belt tooth, a peak is disposed between each groove, the second member cooperatively engages the first member to engage the toothed belt there between, and the first member having at least one arcuate concave surface extending across a clamp width, the arcuate concave surface corresponding with the second member peak when the second member is fastened to the first member.