I recently went from the stock 45c tires, filled at 50psi, to 28c tires filled to 90psi (125max psi) Wow, big difference on how she rolls, but I now have to really slow down when hitting the sections of horribly paved road. Really feels those bumps and cracks in the pavement now, but wow she really wants to fly over smooth pavement, so its always a trade off. Still, I think the rolling qualities of the new tires overcome the cons, so I'm keeping them on.