We just rode X-country 3,800 miles on our co-mo speedster on Hugi+Dyad wheels on Schwalbe Marathon Supremes, 700 x 35c. We’d done several 2-week tours on same with no flats running the low 60psi. After a few tube failures on on XC, we upped it up it to 75 psi and got from Utah to eastern Virginia with no flats. The supremes are expensive but light, low rolling resistance, puncture resistant.