Sixty plus pound windows

Hello,
These windows are aluminum, double pane and are approximately 30"x50". The roller is in a nylon carrier that is about 11/16" wide and 1 3/16 long with a screw hole at each end. The roller itself is flat brass and 3/8" wide with a diameter of about 1/2". See picture. The windows have a single roller at each end and are installed vertically. Double rollers wouldn't hurt and there is plenty of room to install them with the correct carrier. Depth of window frame is about 3/4".
Thanks for any suggestions you can give.
David

Thank you, Paul
Those rollers appear to be much narrower and therefore flimsier than the originals. I will give them a try but don't see good things happening. Perhaps I'll try to add a roller in the middle of the window to spread the stress. It'll be a while before I can get back to this project but I'll report to you then. Thanks, again.
DT