I have a Henderson door that is over 30 years old and doing well. It is the type with the coiled spring across the top and the conical cable rollers at each end.
I noticed that the rollers in the vertical track slide rather than rotate and I wonder if it is due to enthusiastic lubrication in the past.
I have given the tracks a good clean but it feels that there are slight flats on the rollers.
Would I have been better off not oiling the track over the years - and would this have encouraged the rollers to roll?