Does tyre width matter?

[Tompinder]

I'm looking to buy a new set of tyres now that the harsh winter weather is coming to an end. My bike came with tyres of 700x25c, would it matter if if was to buy narrower tyres like some 700x23c or even 700x19c? Or would this cause problems when mounting them onto the rims?

 

[HLaB]

I doubt you have a problem with fitting them, its dependent on your internal rim width if you want to be certain. In theory a narrower tyre has less contact with the ground and hence less resistance but less contact means less grip, p'ture more and rides would be slightly harsher but based on an existing width of 25mm I doubt you'd notice much. I ran a 22mm for a while on my rims which have had 23mm, 24mm and 25mm tyres and all I really noticed is the 22mm pinched p'tured more. I'm currently running 23mm purely because they are more readably available (the popular choice) and clear my mudguards better.

 

[guitarpete247]

I've got less choice than most as I am still using 27" wheels (almost 30 years old). I had Marathons on till a couple of days ago. Well fairy resistant but heavy and slow and wide. A bit of a b*gg*r with mudguards rubbing them unless in the perfect position (and it isn't perfect next time you go out). Took the mudguards off last Saturday. Bliss, silence. Monday got a pair of Conti Ultra Sports 1 1/8s and it purred along . Admittedly the Conti's are about 1/2 the weight of the Marathons so the width bit might be irrelevant but I am noticing the difference.