I run conti double fighter 2's on front and rear on my orange evo2. They've been great for me as I have to commute to work everyday on road(riding through an industrial estate is hell for your tyres) and I can then go offroad at the weekend on them(as long as it's hardpack).

After washing my bike today, I checked the tyres, my front is fine, but my rear is starting to go bald in the middle. I also notices it has quite a few small slits around the centre where stones/glass etc have got in, and I've now dug out the offending items(I haven't had any punctures apart from a large nail as I run a kevlar tape stuck to the inside of the tyrewall).

As I haven't had any punctures, is it worth replacing it or am I tempting fate if I keep running it.

If I should replace it, any suggestions on a tyre, as I love the double fighter but it seems the outer part of the tyre is penetrated quite easily(or is this the same for all tyres?). Is there a tyre with a harder compound I can use, that will be suitable for on and off road and will match with the front(the tyres are 1.9's that I run at the moment).

I know road riding will give me more possibility of a puncture as I have to run higher pressures, but if I don't run higher pressures, I lose a lot of speed. I tend to run my tyres at around 50psi, as apparently they can go to 60 but I don't want them so hard that anything will puncture them.