Abstract: An elevator system including: an elevator car configured to travel through an elevator shaft; a first guide beam extending vertically through the elevator shaft, the first guide beam including a first surface and a second surface opposite the first surface; a beam climber system configured to move the elevator car through the elevator shaft, the beam climber system including: a first wheel in contact with the first surface; and a first electric motor configured to rotate the first wheel; and a controller configured to determine wheel slippage in a low friction area along the first guide beam.