Abstract: A rail coaster operates as a cross between a roller coaster and a zip line. A rail may be suspended under a frame by flexible cables or solid brackets. The rail may turn, incline, decline, or twist, but need not twist to still provide a “rolling” degree of freedom for a rider. An eddy current brake provides proportional braking as a function of speed. A cam-adjustment-axle (eccentric) carries certain wheels to provide finely divided, discrete, but incrementally small adjustments of idler wheel clearances to accommodate variations in the rail, wheel wear, and onsite adjustment of tolerances for curvature, unevenness, and friction. A “static universal” bracket provides adjustment in four degrees of freedom, three of translation and one of rotation in securing a rail to a supporting frame.