My race bike is a very stiff frame and rattles my fillings out everytime I ride it.
I just put some 25mm tyres on there, running 10psi less than normal (100psi) and its transformed the bone shaker into such a comfortable ride.
Thought I'd share the experience for anyone looking for a bit sweeter ride.
In terms of rolling resistance, the bike feels to roll better on rough chip seal type bitument where large stone has been used. On smooth hot mix I don't think its rolling quite as well as 23mm but over all - really great outcome, especially for me were nearly all of our roads are this rubbish chip seal finish.
If you've not tried 25's - I suggest giving them a go
