[tricky]

The book says :

4" tyre.....12lb fr 14lb rr (18")
5" tyre.....12lb fr 12lb rr (16")


Personally I use 14lb fr....and 16/18lb rr.
12lb in the Front will sometimes give you a low speed shimmy with one hand off the bars when changing gear.....so just up them a few lb's at a time.