Help me gauge tyre life!

[spoonman]

Got a big trip coming up, probably 2000 miles. I'm putting a new rear on but I'm unsure about the front. It is a Bridgestone Battlax BT020, I don't know what the current mileage on it is.
It has about 1mm to go on wear indicators. Tread depth is 2mm in centre, 3mm one third from centre and 3.5mm two thirds from centre.
I believe tread depth is 4mm all round new, total life expectancy is about 10k miles so by my logic I should be able to get another 2k out of it ok?

[JZS 600]

Stick a new front on mate, not worth the chance and  possibly more prone to punctures when they get worn.

[Dave48]

Agree. Stick a new front on. You can then enjoy your trip knowing youve got the tread/grip/ability to cope with torrential rain. Small price to pay for peace of mind. Never skimp on tyres .Enjoy trip!

[bikemad62]

1 mm is the legal limit at any point in the tread. But change it anyway the bike will behave alot better. 
 

[spoonman]

Thanks for all advice. I got front and back.

Took tyre advice from other thread and went for Pilot Road 2's.. £200 fitted and balanced, pleased so far.