Ogsarg

In the not too distant future I hope to start looking for a new road bike. One of my considerations is the ability to run bigger tires but not sure how big I would want to go. I don't plan on doing any serious gravel or dirt but do ride some really lousy pavement. My Roubaix had 23c tires on it when I got it and I noticed a big improvement going to 25c GP4000SII's. I don't think anything much bigger would fit.

I am definitely a recreational cyclist. No racing but do some long rides on the weekend and plan on doing a century here and there so want something that rolls pretty well.

I'm thinking the capability to run 32c tires would be enough. Any reason I would need anything bigger for my use?

surak

The pros mostly ride on 28mm tires for Paris-Roubaix at ludicrous speed over pave. I don't think you'll need anything wider than 32c, especially if you get another endurance bike like a newer Roubaix. Big difference in how (not) battered I feel after rides over 50 miles compared to my aluminum bike.

WhyFi

Not that I can think of, unless you're a really large/heavy person.

Personal experience - a couple years ago, I slapped some 30mm road tires on my gravel bike and I was hooked. As a relatively big guy, being able to run fast-rolling tires at 65-70psi made a huge difference in how beat up I'd feel at the end of 3 - 6 hours worth of riding, so I decided that I'd want at least that much clearance on any future road bike purchases. I don't know if road tires are going to trend even larger or not, but I don't really care - 30mm is a nice sweet spot for me. I'd say that I could probably even be happy with clearance for "just" 28s, but some of the new wheelsets at 30mm external width are looking compelling enough that I wouldn't want to rule them out.

Barrettscv 

I also like using tires in the 27-32mm wide range. These include 700x28 Continental 4000 II, 700x30 Schwable S-One, 700x28 Vittoria Corsa and 700x25 Michelin PRO4 Endurance.

I’ve used smaller and larger tires, but the 27-32mm size range is fast on pavement and if the tire is robust, it can be used on firm & dry crushed limestone trails.

Seattle Forrest

28 to 32 mm feels like the sweet spot for me. Comfortable, versatile, and still light enough to feel snappy.

WhyFi

A few weeks ago, my road bike was getting a spring cleaning so, in my hubris, I decided to take the gravel bike on the group ride. Fast-rolling 38s were just fine on the flat bits, but damn does the script flip when pointed uphill. There certainly is such a thing as too wide (any heavy!) when it comes to tires.

Abe_Froman

That sounds odd. I would think they would hurt you more on the flat, fast bits, than on a climb where they really shouldnt be a detriment at all.

Dave Mayer

If you've ridden a 1,300 gram (or less) wheelset, you'll understand the huge effect of rotating mass on climbing and accelerating.

Anyway, I've been riding long distances on gravel lately, and decided to convert a bike with race wheels to something more robust; I swapped out 22mm for 25mm. The new wheels are mid-level Campagnolo clinchers. The previous wheels were irresponsibility light tubulars.

The bike now rides like a farm tractor relative to previous. The bike now tops 20 pounds, with all of the extra mass on the wheels. Hard to believe the transformation, from responsive to sluggish.

jpescatore

I moved up to 32mm and they have worked great for road riding and for the crushed decent gravel road and limestone/packet surface rail trails. For my old beater bike that I use on rougher trails (like the C&O Canal Towpath with is dirt plus roots, potholes, rocks etc.) I'm using 35mm tires and I've tried 38mm that one and bigger is better on those surfaces.

But for the 95% of my riding which is mostly road and just a bit of gravel and those nicely packed rail trails, 32mm is perfect and I weigh 230 lbs. I run the tire pressure at 80 PSI, down from from what I used to run. No meaningful increase in rolling resistance and definitely a decrease in flats over smaller tires/higher pressure.

bruce19

As you are doing research consider tubeless. I recently switched to Mavic USTs and I have been amazed at how light, comfortable and smooth they are. According to testing they are also less rolling resistance than clinchers or tubular. I would not have believed it if I hadn't experienced it.

tigat

Have to agree with Dave and WhyFi. I ride 28s on my Domane and 25s on the Emonda, both with superlight carbon wheels. Even with that minimal difference, accelerating out of sharp turns (like the bridges I cross on the MUP I commute on) and negotiating ramps over 10% feel totally different, and easier on the Emonda, to the point that I'm planning on putting 25s on the Domane for upcoming mountain rides.

On a previous generation Domane, I experimented with 32s, and the current model with discs can go to 35s. I can't imagine ever needing to do so except for the novelty of it or if I decided I wanted to be a gravel racer.

Wildwood 

Width? Depends.
Long rides on weekends? Not race miles, more than a couple of stops in your century.
Comfort over Speed.

New road bike, I know more than a couple folks who would say buy a disk bike that will take 42s. Anything narrower is still possible (and 2nd wheelsets might transform your options).
Or, depending upon your frame size - 650b, might be your thing for recreational miles with a nice set of small bags/panniers.


Who can say?

I'm in the 28-32 on a standard road frame for road+light off-road riding. Preferably tubulars. Not a 650b guy for 60+cm frames. Others want more versatility for their personal adventure.

YMMV

illdrag0n

For what it's worth, i'm 149kg and can't tell the difference between 32c and 28c, but 28's look much nicer.

I reckon the 28s are even more comfortable actually (conti 4 seasons 32 vs Durano Plus 28c)

Rollfast

Anything but flat and bent or wiggly is probably good.

daoswald

Ive ridden 23mm, 25mm, 28mm, 32mm, and 38mm. For my pannier-toting hybrid 32mm is my preference. For my road bike, 28mm.

canklecat

I wouldn't buy another drop bar bike unless it was endurance oriented and would take tires up to 32, maybe even larger. Our roads are getting worse, due to neglect or that cheap and nasty solution, chipseal -- basically pouring goop over gravel and calling it pavement. Sometimes, maybe months later, they'll pour a smooth "fog coat" or asphalt, which is nice. But usually they just leave it at chipseal forever.

My old school steel bike can take up to 700x25, so that's what I use. It's tolerable, between the curved fork and somewhat wider, softer tires. I usually run 'em around 90 psi back, 75 front. (I weigh 150 lbs).

My early '90s Trek 5900 carbon wears 700x23. Larger tires are a marginal fit and there's some rub marks inside the chain stays from a previous owner attempting to use wider tires. That bike is not fun on bombed out roads or chipseal. Good bike but I wouldn't buy another road racing oriented bike. It's not practical for our roads or my age and condition.

My favorite rough pavement bike is an old Univega with flexy frame and fork and 700x42 tires. Doesn't really feel sluggish. I suspect the somewhat slower times are mostly due to the aero issues, not the bigger tires. The bike is set up with albatross bars set at saddle height, not quite upright but not as aero as drop bars.