A riser tensioning system for providing a tensioning to a riser connected to a floating installation via a tension ring. The riser tensioning system includes at least one riser tensioner assembly. Each of the at least one riser tensioner assembly includes a riser tensioning cylinder comprising a cylinder rod, at least one sheave, and a wireline with a first end and a second end. The first end is fixed to the tension ring, and the second end is fixed to the cylinder rod. The wireline extends between the tension ring and the cylinder piston via the at least one sheave.