Rear Derailleur help

[supercooper88]

The rear derrailleur has the limit screws but what does the other screw do ?

Cheers

 

[BSRU]

The rear derrailleur has the limit screws but what does the other screw do ?

Cheers

If it's the one right next to the drop out, then it moves the top jockey wheel "closer to" or "further away" from the cassette.

 

[Asa Post]

It's often referred to as a b-screw.
Information on adjustment can be found about half way down this page

 

[supercooper88]

It's often referred to as a b-screw.
Information on adjustment can be found about half way down this page

Thanks very much