Originally Posted by
irclean
In my experience (admittedly limited) it's not the size of the tires that holds the road, it's the compound of the rubber. Better tires can make all the difference.
It's both - a wider tyre can be set to a lower pressure with same rolling resistance, this gives a bigger and more circular contact patch, which improves handling. But tyre compound is just as important, yes.
When I started riding I was under the mistaken notion that knobby, more agressive tires would hold the road better when things were wet. The opposite is in fact true; slick tires hold the road much better - wet or dry. My hybrid's tires are slick with sipes to channel water away when things get wet and they hold way, way better than the cheap Kendas that came with the bike. Also they are 35s vs. the Kenda's 38s. The same is true for the old MTB that I sometimes commute on; I used to have 26*2.125 knobbies on it, but now I have 26*1.75 slicks and the old girl feels much more sure-footed.
Completely true.