Physics fail. Contact patch is inversely related to tire pressure, not tire width. Contact patch (sq.in.) = Weight(lbs) / Tire Pressure (PSI). Many wider tires run at lower pressure than narrow ones, but this isn't necessarily true. If there were racing benefits to a wider tire, then high pressure, wide tires would be widely available. They're not because no matter what the pressure, you have to corner slower on a wide tire due to the cornering profile.

Because few commuters are running at the performance limits of their equipment, the slower cornering issue is unlikely to affect their speed much.


Weight and aerodynamics may be an inescapable issue with larger tires in the racing context. Perhaps my use of the word "nothing" was too absolute, but these are definitely secondary disadvantages.

You're correct that contact patch area is primarily a function of pressure and weight. But the formula above is an approximation under the assumption that all parts of the tire in the contact patch area press down equally hard on the road surface. With real tires that's not the case and there's more pressure in the middle of the patch than at the edges.

But I disagree on your contention about cornering ability. Car and motorcycle races depend critically on cornering ability and if there were an inherent benefit to skinny tires then you'd find them in those sports. But the opposite is true - with quite wide tires being used. OTOH, in bicycle racing the most important concern is minimizing drag and weight since the available power is so limited. A skinny tire wins here in three ways: 1)air resistance is less, 2) higher pressures can be used for a given weight and construction therefore reducing rolling resistance, and 3) the weight will be less. And yes, the wider tire actually has a little less rolling resistance *if* both are run at the same pressure and are otherwise similar. But in practice the skinny tire can be run at much higher pressure than a wide tire of similar construction and at that higher pressure the rolling resistance will be less.

But for commuters these effects are pretty small. I regularly switch between my road bike with 23mm tires and my touring bike which currently has 38mm and 35mm tires. Can't say that I really notice much effect on my speed even in fairly fast group rides. But I'm pretty sure they'd become significant in any racing situation.

what took me by surprise (I did the opposite- went narrower- 32 to 28) was that I had to recalibrate my computer for a different wheel circumference. The compounding of that couple millimeter decrease in circumference resulted in a ride on the same route as my previous ride reading as 1-1.5 miles longer after I switched tires. Wild!

I want my next bike to be a Cross Check with 700x50 Fat Franks.

recently switched from 23 gatorskins to 25s. im liking it

The 20mm difference in circumference https://www.sheldonbrown.com/cyclecomp_c.html
would lead to a one mile discrepancy over roughly 100 miles... if my math ain't too wonky

Do it! You'll love 'em, they're awesome tires. I can't wait for summer, when I get to remount mine.

I've got road bikes with 23, 25 and 28 mm tires and to be honest, I notice very little if any difference in comfort between them. However, the roads are in pretty good shape where I ride. Smaller tires are generally lighter, and that makes a noticeable difference when riding on hilly terrain.

My experience is the exact opposite. I've ridden many years, and over time my tires have gotten smaller. 10 years ago, I thought of 32's as narrow and certainly didn't want skinnier. Now, I don't run anything but 23's.

Except on bad surfaces, I see no advantages to big tires, and it would take significant amounts of gravel, snow, or washboard surfaces to convince me to go bigger.

I use 700x50's, but not on my Cross Check...they don't fit. You may need to look at something like the Van Dessel Whiskey Tango Foxtrot.

I ride roads for commuting and don't have to go on trails or gravel. 23 are faster and lighter.

Heh... was running 35's on the hybrid and fitted some 45's.

Looks like a 29r but dang does it ever roll through the snow now.

Narrower tires and higher psi does not automatically mean faster... tires need to be inflated so that they deflect by about 15% of their depth to be most effective and the aerodynamic difference between a 23 and a 28 is very small.

A wider higher volume tyre run at proper pressure will absorb shocks better and you will be hard pressed to push these to the limits of their handling... if the psi is too high your tyres will not absorb shocks, traction will be decreased, and you will have a higher probability of the tyres skipping off objects which can be very bad in high speed turns.

With better made performance oriented 26 inch tyres you have compounds that roll fast, have a small contact patch when they are run at the higher limits of their psi range, and casing shapes to maximize traction in corners.

Most fit individuals can ride at speeds around 30 km on any reasonably aerodynamic set up and tyres will not play a significant role unless you are running at much higher speeds.

Weight does play a small role as well but even then, the difference between a light weight racing tyre and a good commuter tyre may only be as much as half a bottle of water and as commuters usually carry more gear and aren't all lycra'd up wider can often be much better.

Come summer I will run the 700:35's on my hybrid but for winter the more massive rubber and deeper tread really makes life easier and my commuting times have not been impacted too much by the cold and weather and my wider tyres.

It's not just about how much weight there is, it's about where it is. It's one thing to just carry something in your backpack or pannier. And quite another to have it on the wheels. The extra pounds in your backpack just need to be propelled and accelerated forward. But the heavy tires need to be propelled and accelerated both linearly (forward) and angularly (around). So heavy wheels will affect your acceleration a lot more than a bottle of wine in your backpack. And how often do commuters need to accelerate? Well, it depends on where you ride, but I have about 20 stop signs and 25 traffic lights on my 7-mile one-way route to work... (And cheapo heavy wheels with kevlar-belted tires on my commuter. )

Somewhere I think we lost sight of the original tire switch. Sure, what's been said about rotating weight, tire width, et cetera is all true, but does it matter. Let's take weight, for instance. A 700x23 Conti Gatorskin with wire bead (chosen for apples-to-apples comparison) weighs 280 grams. The same tire in 700x28 weighs 360 grams, so now that's an 160 gram bottle of wine in our backpack we're using for comparisons, right?

On the other hand, if you're using something like the 700x50 Schwalbe Marathon Supreme (as I am), you've got 645 grams per tire -- nearly an extra pound per tire -- and most of that weight is rotating about an inch farther away from the hub, further multiplying the inertial effect. Can I feel that difference? Yeah, I think so, but it's not as dramatic as you might expect. I'd say it's less than the difference I feel from having either tire underinflated by 10 percent or so. The worst part is having two and a half inch wide fenders, which really suck going into a headwind.

30yrs ago I commuted and trained on 28mm tires while racing on 23-25mm. Now I'm old and fat and 35mm is the new 28mm.

It is called rotating weight and I understand the concept... would never tell you that my touring bike with it's 26 by 1.5 Marathon's could ever accellerate as fast as my P20 folder with it's 406 Comet Primos and even my road bike would be hard pressed to match the pickup you get off such light and aerodynamic wheels.

But there is always a trade off between weight, ride, and durability and I think we're still in the commuter forum where weight weenies usually fear to tread.

Got to playing with my Trek this afternoon and besides the 700:45 up front I now have a 700:38 Avocet Cross tire in the rear and just came in from doing some road testing on the hard pack and in some deep patches of snow.

Have to give the ride an A+ and the combination of the wider and knobbier front tyre with a slightly slicker but still grippy tyre in the back makes the Trek pile through snow better then my 26 inch wheeled winter bike as it digs in a little deeper and floats less.

And once you get those slightly heavier (and probably tougher) tyres up to speed they like to maintain that inertia.

Have taken my touring bike out on faster paced rides and had friends struggle to keep up with me as after you get past the weight of the Marathons, they roll out pretty fast.

I switched the stock 2.1" Big Apples on my Big Dummy for 2.35 " can feel the diffference, not huge, but there. I do find them slower, but for an indirect reason. i often don't realize how low the pressure has gotten, until i stick 60# or more on the back. Hmmm.... Feels a bit wiggly. Check. YUP! 20 psi or less! Flats? Not so as you'd notice.

A 38 in the back and a 45 up front...

Funny. I just switched my 700x32s over to my Commuter and my 700x28s over to my hybrid bike. I like *both* bikes better now. The Hybrid tends to be used for shorter start/stop trips.

After learning that bigger tires at the same pressure actually roll better, I upgraded my Ebike (Giant Twist) from 700x38s to 700x40s. The ride has improved and I think my range has even improved. May try the 700x40s on the Cross Check Commuter soon just to see what they're like.

I'm running 28s on my road bike, a LeMond Zurich. That's as big as you can fit without the tire rubbing the top of the fork. Sometimes I have to let out some air to get the tire past the brakes.

28 is a nice width for a road bike. 25 is good, too.

I like the hold on the road a wider tire provides. Smoother ride, too, and fewer flats.

I'll never go back to 23-thin tires. I'm surprised that is what most riders use.

My commuter is running a 32 on the front and a 35 on the rear, because I also use that bike for grocery shopping, and sometimes it is carrying a load.

Thats to denote that it's a Clincher, as opposed to a tubular. Any commuters ride tubulars? I don't know any, but I'd be interested to hear from any who do, and why. Racers still love tubbies.

I seem to have the opposite experience than most - I started out with 32c cross tires (stock), and went down to 25c gatorskins. I barely felt a difference in ride quality, and while there are times I'd like wider/knobbier tires (riding on gravel, for instance), I don't really regret the change.

That's the first time I've heard that explanation for the 'c' after the tire width (in mm). But I've seen the 'c' added after tubular tire sizes as well - for example here:
https://www.competitivecyclist.com/pr...FQRubAodVH2w1Q

copied this from another forum:

"International Standard ISO 5775-2:1996, Bicycle tyres and rims — Part 2: Rims: document:

"ISO 5775-2 defines designations for bicycle rims. It distinguishes between

Straight-side (SS) rims
Crotchet-type (C) rims
Hooked-bead (HB) rims
Rims are designated by their nominal rim diameter and their nominal width, separated by a cross (× ). Both are measured in millimeters. The rim type codes SS or HB precede the rim designation, whereas code C is appended to the nominal width."

some examples would be: SS 400×20, HB 422, 700x23c, the "C" designating a Crotchet rim.