Tire size ride quality???



two wheels said:
Is there a big difference between 700c x 23 to 700c x 25?? ( ride quality and speed )

A little bit cushier on rougher roads, with a feeling of having a better grip when cornering in wet / rough & a tad slower on smooth flat roads.... not a big difference.

If I only had one set of wheels, for where I ride I'd choose 25 mm.
 
I choose 25's when I can. 25's:
  1. Give better grip 'cuz of they're contact patch, which is bigger because of the lower pressures you can use.
  2. Are better in the rain and on gravel and dirt.
  3. Are more comfortable. You can run lower pressures, and lower pressures mean better bump absorbtion, vibration damping, and a shiny chi.
  4. Have marginally better puncture resistance, everything else being equal.
  5. Will have a longer life than 23's, everything else being equal.
 
To answer the OP's question, there is not a big difference between the two...
 
I have 25's on my new ride and have to say, so far I love it. I had 28's on my old one, so I had to get used to the sensitivity factor a little, but now it's great. I don't think I would go to 23's, not for regular road riding anyways, (maybe for a high speed/sharp cornering race), but for longer regular road rides, stick to 25's.

-Greg