iab

The few articles I have read state while 2014 and 2015 frames are rated for 25mm tires, most will go up to 28mm. That is a far contrast in just 10 years, perhaps even 5 in that those bikes don't fit a 25mm.

And really in boils down to surface. Ride a wood track? Break out the 20s. Illinois pavement? I'll take the 25s. Washboard fire roads in northern Wisconsin? I'm on 32s.

andr0id

You are over generalizing the conclusion.

I think current testing shows that a good quality 25 is faster than a good quality 23.

I don't think you can assume that a 28 or 32 will necessarily be faster than either of those though. At some width, there is probably going to be an increase in rolling resistance and certainly a loss with regards to aerodynamic cross section.

iab

Conservation of energy, basic physics. While the extra weight is "bad" uphill, it is "good" downhill. It evens out. Same with acceleration, while harder to accelerate, it is also harder to decelerate.

I also don't understand the carbon rim thing. You know you can mold the tire seat in any way. It is independent of the rim profile.

lotekmod

A good question, though I generally don't look at professional TT bikes for inspiration on how to set up my road bike. I was curious though and my 5 minutes of internet search turned up this:

Tour de France 2015 time trial tech gallery - BikeRadar USA

Somewhere in that photo gallery is a photo of a tire with the caption "Astana are on 24mm Specialized Time Trial 2 tubulars". So even the most serious of speed weenies appear to be going with bigger than 23mm tires. I can't see how any recreational cyclist would be losing anything in terms of speed or handling with 25mm tires, meanwhile gaining in comfort and flat resistance if nothing else.

Barrettscv 

A 25 or 27mm tire on a wider road rim can roll as fast or faster than a 23mm wide tire.

A larger tire will run faster than a smaller tire if you run lower air pressures. That's good to know when you decide to go for a bigger tire because you like a more comfortable ride or ride on bad roads with potholes a lot.

What will be won in the rolling resistance department will be lost in the aerodynamics department. I'm not sure at what kind of speed this turnover point would be, but it's probably above 20mph. This also depends greatly on the tire/wheel combo. A 28C tire on a rim that is designed for a 23C tire will be less aerodynamic than the same tire on a wider and deeper rim.

All in all, I think the differences aren't that big, especially between the 23C and 25C tires.

revchuck 

As noted above, current research shows that 25-26mm tires are faster than 23s. This being C&V, it's no surprise that some folks reject that out of hand. Some notes:

Most current race bikes have room for 28s. I could probably run 30s on my 2015 Allez Comp Race. I'm currently using 25s that measure 26.

Pro racers race what they're given. That said, their reason to race is to win. They're not going to use something solely to sell it. That's why carbon wheels weren't seen at Paris-Roubaix until a few years ago - they weren't strong enough to last. Now they are.

Pinch flats are almost always due to operator error. Either the rider was too lazy to check tire pressure before heading out or was lost in the ozone when that pothole reached out and grabbed the bike (BTDT). If your tires are inflated correctly and you're paying attention to the road, they rarely happen.

None of us are getting paid to ride our bikes. Some of us had our impressions of what a fast bike should feel like formed 30-40 years ago and keep that as our basis. If that gets you on the bike, it's fine with me. Fun is not objective.

eschlwc

doesn't it depend on the rim?

i ride 23s at 100psi on narrow rims, because i like them and they feel great to me.

as already posted, "ride what you like."

OldsCOOL

If my C&V tradition ruled my choice of tire I would still be riding a sluggish 27x1.25 gumwall. Not that there is anything wrong with gumwall.

I love these circuitous tire size arguments. This will never be settled by current research/studies/science because some of us dont ride in the TdF peloton.

fender1

This whole thread = waste of time. The arguments always seem to boil down to:

1. Skinny tires are faster than fat tires, Jan Heine is nothing more than a product pushing shill....
2. Fat tires are faster, Jan Heine, is a cycling saint, logs thousands of miles and has forgotten more about tires than you will ever know....
3. Hey, let's all get along ride what tire you like the most.

I say we switch the topic to something more interesting like Rivendell and what rip-off they are or does it make sense to wear a helmet when riding a bike?

pcb 

I'd say it would have been more accurate to say that, in general, wider tires have lower rolling resistance. I don't know if there's a point at which that stops being true. My "common sense" tells me probably, but I'm not an engineer or scientist, so my "common sense" has no grounding in actual mechanics or physics. We'd also need a better/broader definition of "faster," since attained speed is dependent on more than just rolling resistance. Tire weight and aerodynamics matter when discussing pro-level performance. Not so much at my slow speeds.

And the lower rolling resistance for wider tires only holds for "all other factors being roughly equal." Tire construction and rubber compound characteristics also play a part.

A look at these two tests show the complexity, even in just discussing rolling resistance:

Continental Grand Prix 4000S II 23 25 28 mm Comparison The 28s have the lowest rolling resistance, and at lower pressures the differences increase. No GP4KSII in 30 or 32, so there's no way to test wider. Wider rolls faster, no question.

Where the rubber meets the road: What makes cycling tires fast? - VeloNews.com 34 tires tested. In general, the wider tires have lower rolling resistance, but there are some 22s that beat other 25s

revchuck 

True - we all ride for fun, and the definition of "fun" varies from person to person. Part of my definition includes racing, hence my choice of tires. Part of my definition also includes drinking coffee in the morning and discussing this stuff on the internet.

embankmentlb

That is why none of us care at all how much the bike or the rider weighs.

Carbon rims, frames all gain their strength from bulk and width. Wide rim, wide tire.

nlerner

Can't we just complain about Eroica's rules? Or the USPS/FedEx/UPS conspiracy?

ppg677

OMG will people stop presenting data with misleading Y axis scales!!!!

And this data confirms exactly what I've been saying. Riding a 25 tire at 100psi has higher rolling resistance than riding a 23 tire at 120psi.

Another way to look at this is that wider tires allow you to lower PSI and not go slower. But if you're riding wider tires *and* lower pressures (come on, admit that you are), then you're probably NOT going faster.

Sir_Name 

I hesitate to add this here...

https://janheine.wordpress.com/2016/...ing-something/

Note also that a reason for performing a rolldown test when studying rolling resistance is to eliminate the biggest variable in bicycle performance, the motor.

Additional reading from the same source:
https://janheine.wordpress.com/2012/...ance-of-tires/

There's no one solution for everyone, do what fits your needs. Research as much as you like.

McBTC

Of interest to me in the article you quoted is that...
So, when I rode 23s, what I thought about them probably was what can be expected from 25s and currently, I'm actually riding 27s not 25s... which explains a lot as I never had an issue touring with 25s.

Lazyass

You probably are going faster because the tire will conform to road irregularities better and do less bouncing over them. If you ride glass smooth roads it may be a non issue but I know my roads aren't like that. They also corner more stable because you have more rubber on the road. I haven't ridden a 23 in probably 8 years now. No measurable difference in average mph, just a smoother ride. Heck, on my bike with 32's I still have about the same average mph.

McBTC

From one of the link the author says...
We see the same thing surrounding what people believe to be true about crank length. The research shows that while not accepted, nevertheless, there are folks out there -- maybe most -- riding on 175mm cranks who could increase their performance by simply going to 145mm cranks; and, they will never know nor question the conventional wisdom.

Machine Age

Wait...you're saying with wider tires I can go just as fast but be more comfortable? Or inflate them to the same pressure and go faster?? That is some GREAT NEWS!

Signed,

32s in Los Angeles

OldsCOOL

Agreed. I most likely will get in on a race this summer and have been snowriding in training the past 7 weeks. I guess part of my reason in tire width preference is due to our smooth roads and cleaner roads in the area.

OldsCOOL

Right on. My snowbike (it's how us N Mich folk ride year 'round) is a 1.95" knobbie and 23psi. It's like riding with a numb butt and peddling a bulldozer.

Bikerider007

23's are too much. JK I picked up three of these new in the box from a guy I bought a bike from. He asked if I wanted anything out of his junk box as he got into mountain biking now. I didn't even know the size or what they were but glad I took them!

I stick to 23/25's on most everything but mountain. Slim tire looks great IMO.

Wildwood 

I've got a clincher wheelset, Spinergy Xaero, I run 20mm on front - I don't expect to be faster than the 23s but a tire the same width as the rim DOES look correct (and cool IMHO).

davester

You are talking about the size of the contact patch, which is controlled exclusively by rider+ bike weight and tire pressure. However, the shape of the contact patch is more important than its size and is the primary variable that affects rolling resistance, as elucidated by the article you linked to. The excessive tire deformation involved in creating the long contact patch of a skinny tire is the reason that skinny tires have higher rolling resistance than fat tires given the same tire pressure. If you choose to keep rolling resistance constant rather than pressure, then the pressure in the fat tires needs to be much lower than the pressure in the skinny tires. Reducing the pressure in this way is what most people do, because it has two additional advantages: 1) comfort; 2) less energy lost due to bouncing the bike and rider up and down on roads that are not billiard-ball smooth.

Leonard Zinn explains this quite well: https://velonews.competitor.com/2012/...rethren_209268

McBTC

Still, many boil it down to the contact patch --e.g.,

25 vs. 23 | Is Wider Really Faster? | Competitive Cyclist

I read somewhere that it has nothing to do with the size of the patch. For a given weight, the amount of rubber on the road will be the same irrespective of whether you're on --e.g., 23s or 25s. But, the shape of the patch will be different: 23s will have a longer patch and 25s will have a wider patch. For the longer patch you essentially are always climbing over a small bump created by tire deflection of the narrower tire.