A catheter assembly includes a catheter, including an inner member and a sheath, extending from a handle. The handle includes a housing, a braking assembly, a carriage and a carriage driver. The braking assembly comprises a braking element within the housing interior and a braking element rotator. The carriage comprises at least one carriage braking surface engaging the braking element. The carriage driver, such as a spring, biases the carriage towards the proximal end of the handle. The inner member has a proximal end secured to the housing. The sheath has a proximal end secured to the carriage. Rotating the braking element causes the carriage to move proximally as the carriage braking surface slides along the braking element. This causes the sheath to move proximally relative to the inner member.