Wildwood 

I bought into the current trend of fatter tires with my last purchase. Veloflex Arenburg (25) & Vlaanderen (27). My first impression is that they change the feel of a lightweight race bike toward too soft on pavement. Think I'll stick with 22/23 on these bikes in the future. Wider tires are for white roads.

edit: More rides needed for a complete/final opinion.

OldsCOOL

I'm totally sold on 23's for nimble handling and acceleration. To me, feel is everything and there is a difference. No 25's for me.

Spoonrobot 

Depends on how nice the roads are and if they're wet.

If I were riding the 13+ foot wide, recently lain roads up in Gwinnett county I'd be more than happy with 23/25s. If I'm down in Atlanta duking it out with SUVs on roads that are barely 9 feet wide dodging potholes and steel grates I'll take 32s and most often 42s.

due ruote 

This is really a ymmv subject. I doubt I will ever buy tires again that are smaller than 25. I find the pressure necessary in a 23 makes the ride harsher than I prefer, with no discernible upside. Mind you, that's discernible by me.

79pmooney

The tires themselves have a lot to do with this. If you ride good enough tires, there is no downside to the fatter ones. (Well, OK, a little weight and a little air resistance.) And if you have to corner on steep wet roads that might have gravel, there is a big upside.

Ben

SJX426 

I am not convinced it is only related to tire width. Overall tire construction can impact the ride quality to the point where there is a significant range of performance within a tire width.

carbomb

Replying to the question in the thread title:

It all depends on your pavement. There's a big variety between cities, hell, within Los Angeles there's a HUGE difference between PARTS of the city. Where I do my fast training rides of course has nice pavement. Where I ride if I'm commuting or running errands can go from a fresh laid bike lane to "is this cyclocross?"

I think this is more about your definition of "pavement" =)

caloso

I think you may have nicer pavement than we do. I have a buddy who does road races on 27mm tubulars due to the terrible condition of the roads we race on.

davester

Definitely skinnier tires "feel" more lively (aka bouncier, skittish, uncomfortable) whereas wider tires are plusher and don't feel as fast. However, based on bike quarterly's testing and on my own experience, the skinnies are slower than the fatties given equivalent construction. Also, there is no doubt whatsoever that the fatties give much more secure cornering. I got sucked into the "skinny tires are fastest" hype for decades, but now I have been completely converted back to more reasonably sized tires. Given that I weigh 185, I will not be running anything less than 25 mm ever again and in general I will stick to 28+ mm.

Spoonrobot 

What size tires have you compared? I've found my 650bx42 set-up to be exactly 0.5 mph slower than 700x28 on the same bike. What I've been wondering is if that's due to the tires or to the significantly wider fenders required?

velofinds

As a single data point, I will just say that my 28mm Grand Bois Cerfs and 27mm Challenge Paris-Roubaix (which stretch to wider than their listed size) feel every bit as communicative and fast as my 23mm Vittoria Open Corsa SC IIs and Veloflex Masters. Good tires, all of them, and I believe that plus appropriate tire pressure are the key differentiators versus tire width.

ppg677

Yup, wider tires is like taking a Ferrari and putting shocks from a Buick Park Avenue on it. The bike will go just as fast in a straight line, but handling substantially changes.

Salubrious

How much weight is on the tire is a big deal. I got tired of the pinch flats that were unavoidable with 23mm on the road. Going to 25mm was not much better. I can imagine someone doing well with them if they weigh maybe 50 pounds less than me. I found that I could go a lot faster on 28mm as I could handle what the road was throwing at me with much greater ease.

peugeot mongrel

+1
25mm Continental GP4000s II at 100psi - fast and forgiving - my go to.

nlerner

I have found dialing in the right psi is key. And it varies from tire to tire, even among those with the same width.

ppg677

I weight 220 pounds and haven't had flat problems with 23mm tires. I inflate to about 110 to 115 psi.

I've taken a bike and swapped wheelsets on back-to-back around-the-neighborhood test rides, changing between 23mm and 32mm. The difference in handling was unbelievable.

McBTC

25s are faster than 23s according the research (the contact patch for 23s and 25s is the same and given that speed has more to do with the shape of the contact patch) but, these findings are based on 'actual' sizes, not what's marked on the sidewall (tubulars are more accurate in this regard). You have to measure tires to know what you're really riding on. My OEM 25s are more like ~27s. I rode 23s for years and thought they were great but it would not surprise to learn that they were actually 25s (especially when riding on wider as opposed to narrower rims).

Salubrious

What tires??

noglider 

I still prefer 28-32 mm for most kinds of riding. It's largely a matter of taste.

jyl

With 25 mm I use 90-100 front, 110-120 rear. Lower gives more pinch flats and requires frequent re-inflation. Ride quality is fine on smooth roads. On bad roads, comfort suffers.

clubman 

Agree with ymmv. I weighed 195 lbs and rode 20mm Michelin Hi-Lite Super Comps in the 90's and loved them. 28mm was for touring. Now I like 23mm for road riding but no more.

I like fat tires on fat bikes, skinnys on fast bikes. Pinch flat = low psi (ususally)

Erwin8r

25mm tires feel every bit as fast and provide more cornering security for me than 23's do--some of it is psychological, but as mentioned elsewhere, research also supports this. On my modern bike, it's Michelin Pro 4 endurance... But I'm no lightweight, so definitely ymmv.

bikemig 

YMMV for sure on this issue. I never liked 23c s all that much though. I used to ride 25c a lot; lately I've been riding 28c tires. I think some of it has to do with speed. If going fast, some of the weight will move off your butt and to your hands and feet; going a bit slower a wider tire is better. I don't race anymore and the 28c tires work for me now well.

fietsbob

Its a Seattle randonneurs club + readers of Jan Heine's Paper , Thing ..

gugie 

Inquiring minds desire details - testing protocol, tires used, etc.

From a weight perspective, if you were doing a test from a standing start on a hill, the wheel with higher angular momentum (typically the heavier wheel, if the radii where the same) will take longer to get up to the same speed. If you were testing over a certain distance downhill, it will be faster. In addition, wider tires will be less aerodynamic. On the other hand, at the same speed, the higher angular momentum wheel will coast you up farther on that hill.

On another note, I'll race you up the Iron Horse Trail between North Bend and Cle Elum, WA on your 28's, uphill or down, your choice.