I can see some life left in the front but my rear is shot. The fitter (selling tyres for a living), suggests both ends are changed. I do follow this rule with the cars and usually swap all four corners at once when down on tread. I'm doing the same for the bike but wondered what the collective wisdom is? Personally, the front has seen the same miles and actually, I really only scrutinise the rear properly. It's probably the front is worn and squared a tad, although I'm not impressed at mileage - about 2,000 from Rosso Corsa. I'm fitting the same as profile is odd for a SF848 and the Supercorsa is softer still.
If you're putting same make on then just replace rear, fronts normally last for 2 rears which is why some firms do a 2R+1F deal. I have used mixed brands before now cos I'm a tight wallet but I'm not getting my knee down or such antics, mainly fast touring. I've got Michelin PR3 front and PR2 rear on my 999, sports touring tyres, last forever and enough grip for my riding.
Personally I'd just have them both done if the front is going to need changing soon anyway. Just had a new set on mine, oddly the front was in need of changing before the back, which seems pretty shocking!
if you're going to get less than a 1000 miles out the front I'd probably change if they will do you a pair deal. If they wont do a pair deal, I'd head back when its fecked.
