The original rubber came loose so we needed a replacement. It fits on the original tyre and can be screwed in place with the existing mounting holes.

Printing:

We used three walls and 20% infill with a layerheight of 0.3mm.

For testing purposes one wheel was printed in black TPU and one in green PLA. 

The PLA one broke after one season, see my make. The TPU one is holding up strong. Will try PETG next.

Fitting lawnmowers:

Flymo: 1200R
Gardena: R38Li, R40Li, R45Li, R50Li, R70Li, R80Li
Husqvarna: Automower®105, 305, 308
McCulloch: ROB R600