Garador Mk3C roller question

[dal5band]

I have a MK3C garador canopy garage door about 25 years old ! - does anybody know how the rollers are held on the spindles on either side ?

One of the rollers came off and I unscrewed and pushed the metal channel aside to put the roller back on but it seems to just push on and it is a very loose fit. Is this because the rollers are just worn out or is there something missing ? Is the roller just held on the spindle by the channel or is there a circlip or something ? The spindle does seem to have a knotch on it ?

 

[dal5band]

answering my own question here - may be useful to someone !!
I got a couple of new rollers and as you push them onto the spindle, they click into place. The internal bore of the roller has a small rebate which clicks into place on the "knotch" on the spindle.
Obviously the old rollers had worn smooth on the inside.