Wayne, I have had a HED3 on the front of our tandem for the last 3,000 + miles, at 120 it is a little harsh, at 117 it is firm but comfortable. On our ride Thursday the front tire was inflated to 117psi and the rear to 120psi. We could both tell that the ride was harsher than what we were experiencing with the HED3 on the front at 117 and the Spinergy on the rear at 120. So as an experiment I set the pressures at 110 and 115, the ride was comparable to the way it rode with the Spinergy rear, tomorrow I will go with 115 and 115 to see how that feels. BTW we rode the exact same route both days and will probably ride that same route tomorrow as those roads have not been chipped and oiled recently.