I've got a back tyre on my Brompton that certainly doesn't stick and I'm going to get something better as soon as I can decide what.
The Schwalbe Marathon tyre stinks! Do not buy them as they are deadly in the wet.
The tyre wall indicates the maximum pressure should be 65PSI but I have resorted to running my back tyre at 45PSI just to get any grip on damp roads. I have been sticking with it (no pun intended) throughout the summer, but I had a brown pants moment in the wet weather this week whilst turning right into a junction. I think Valentino Rossi would have been impressed by the way I recovered from what felt like an enormous rear wheel slide.
The Schwalbe Marathon Plus has been recommended but I'm cogitating whether I want to risk wasting more money with Schwalbe.
What's the alternative?