How Cold Of Temperatures Can Hydraulic Brakes For Bikes Handle?

How Cold Of Temperatures Can Hydraulic Brakes For Bikes Handle? The DOT systems behave well down to at least -50F. Mineral-oil systems show slower retraction starting in the -20s or so but still perform well as far as braking. Riders have a variety of problems with their bikes in winter; some problems get misdiagnosed, and