Ah yes, a technology so simple that there is no low gear adjustment, at least not in the sense of later front derailleurs. First you position the cage so the chain clears it in low gear. Then you limit the travel outwards so as not to throw the chain when shifting onto the high chainwheel.

It'll take one or two tries to get it right. Set the cage, then sprint a hill. If you still have a bit of rubbing, reset the cage, then resprint.

Despite the primitive simplicity I love the Gran Sport. Mine absolutely snaps the chain onto the high chainwheel on the Raleigh. Originally I though I'd want to find a Record to replace it. Once I remembered how to set it up, it's staying right there.

Syke
Deranged Few M/C