Harry Bloomfield, Esq. wrote in
:

JohnP formulated on Thursday :
Clean tracks and oil on the spring.

No springs involved at all.


I have found that the rollers in the tracks start to skid and then
get
flats on them. They would be better with rubber tires!

There are no rollers in the tracks either. The ends of the alloy
slats,
have a nylon block fixed to every second slat, which keeps the slats
centralised in the guide channel.


I hadne;t appreciated it was a shutter door.