I recently bought a second-hand Alu Fort Track 7005 which has a forward sloping top tube i.e. it's considerably higher at the junction with the seat tube than it is at the junction with the head tube resulting in a very short head tube… anyway, I was cleaning all the gunk off it as I'd bought a couple of new parts for it and noticed two cracks on the head tube, one about 3mm long starting at the top of the head tube and going down, and one about 10mm long starting at the bottom and going up (and actually hitting the weld). Both are on the back of the head tube and considering that my entire head tube is only 9cm long, a bit worrying.

The burning question is, is it safe to ride?

To be honest I'm really gutted as I've only just bought it and was really getting into riding fixed. I don't want to have to fork out for a new frame and at the same time I almost don't trust second hand anymore.