Chain catching chainguide

[rossoreed]

Just replaced the gear cables on my bike today, which went well, and have done both the rear and front derailer alignment as per the (brief) Shimano website instructions.
The gears now change smoothly, but I have noticed that when I have the chain on both smallest sprockets (both front and rear), the chain catches the chainguide and rattles. It does not catch at any other sprocket setting.
Is this normal? or have I not set them up correctly.

Shimano SORA FD/RD3300

 

[al78]

You shouldn't use the small-small or big-big together because the chainline is at its most extreme angle. This ultimately accelerates wear and tear on the drivetrain, and is the reason why the chain is rubbing on the chainguide. It is not necessary to use these combinations as those gears will be (approximately) duplicated by another sprocket-chainring combination which will have the chainline running much closer to parallel with the frame.

 

[rossoreed]

Great, thanks guys.

Paul