One of my bikes is a lovely old steely (about 15 years old) Normally it rides like its on rails. Beautifully smooth, nice steering, responsive etc. Today was the first time I took it out on a good ride on my usual 72km/45mi circuit after changing the tyres from Conti GP4000 700cx23 to exactly the same but 700x20. What a difference! Gone was the smoothness, the security while cornering at speed, and my backside got sore after a couple of hours, I felt every little bump in the road.The bike didn't feel any faster but I did a pretty good time even though the wind was up gusting to 30 knots. The lesson to be learnt from this? Narrow tyres 'might' be a little quicker, they are much harder to fit, and they ruin your ride. I really can't wait until they get slashed to pieces by the glass on our roads so I can change them back to 700x23.