Google Search still works for me: https://www.businessinsider.com/...essure-faster-2018-7

"For what it's worth, we didn't see any 23mm tires at the Tour this year — we did look at a lot of tires — though of course we may have just missed them. By far the most common widths were 25mm and 26mm."

If you have older, narrower rims, then common sense says you should use narrower tires, like 23mm or less.

Do you care about how fast you are riding?

I still don't have a clear answer to this one - despite all the ST discussion.

Do you care how fast you are riding?


Of course I care, that's why I'm asking for a clear answer.

Answer - more rubber on the road, less air pressure, more comfortable ride, AND FASTER. Ture?

Would you say this is true, even with a narrower, older rim?

What wheels do you have?

I highly recommend the Continental GP 4000 II tires. They are probably the most loved here and best all around performer that gives you long life, durability, good aero, and low rolling resistance.

If you run 25mm tires on older, narrow rims, they will be tougher to remove through the brakes. So, I would go with 23mm.

Personally, I run their 25mm tires on my road bike with skinny (22mm wide brake track) wheels. It is a small hassle to get the wheels off, but worth it for the comfort and performance.

I agree with exxxvii. I ride 25mm Continentals on my training wheels regardless of rim width. Less rolling resistance and just more a pleasure to ride. If you have a narrow rim which my tri training wheels are they won't be as aero but who cares I'm training and I want comfort. I run tubs racing so a and a 25 on my Hed Stinger rear disc and a 23 on my Hed GT3 front which is designed for 21-23.

Years ago when cycling we ran 18mm continentals at 150psi because they were supposed to be faster rolling resistance. Rim width, shape and aero are all a more recent thing.

Latex tubes are fast.

For a wider rim, 24+ will likely roll faster. On my tri bike I run the "wider" newer Heds with Specialized Turbo 24's at 80 PSI; they are noticeably faster than 700x23 Schwalbe Ones I was using before and the ride quality is great. 700x26 won't fit my BMC TM01.
On my road bike, running 25mm wide carbon rims with 700x26 Specialized Turbos at 80 PSI. They feel fast and fantastic.
http://www.roadbikereview.com/...cher-wheelset-review

Assuming same wheelset, tire model, and both the 23 mm and 25 mm tires are pumped to their optimized pressure (key part here), rolling resistance is essentially the same between the 23 and 25.

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For racing, I'd check what tire size the wheel manufacturer recommends for the rims you are on. If you can't find that info, I might go a bit against the grain and say go a bit narrower up front (probably 22 or 23mm) for a good tire to rim aerodynamic transition on an older rim. On the rear, its likely not as important, and you can go wider if you want more comfort for a longer event/poor roads. Keep in mind that even HED"s Plus rims (25mm wide) are still optimized for a 23mm tire, so I'd imagine a narrower rim would be best at those narrower tires also. Sure the wider tires do roll a bit faster, but at race speeds I'd say the aerodynamic effects outweigh the very modest gains in rolling resistance.

For training, it really doesn't matter but I would probably stick with whatever you plan to race on (nothing new on race day!) so you are familiar with it, what pressure you like etc.

Remember that the TdF guys are all on tubs which generally have wider rims. For example, DA C60 tubular wheels have a 28mm wide rim, making 25's fit very well aerodynamically.

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If you are riding narrow rims I would guess you are also riding an older bike. I have an origin Shiv TT, 1st gen Venge and a gen 2 speed concept. A 25 is either a no go or major hassle to run on these bikes because they just weren't designed for anything wider/taller. I am sticking with 23s until I get a new frame.

Well, this is now all perfectly clear. LOL Thanks for all the answers/input.
At the beginning of this thread, it seemed like I was pretty stupid for even asking and wider tires are definitely "better". Even on narrower, older rims - advantages - more comfort, lower air pressure, as or more aero, more rubber to the road - disadvantage - if brake calipers is set for a narrower rim, it may be more difficult to slide the tire/rim off the bike. Is that about it?
The more recent answers to this thread - I might as well continue to use 700 X 23mm tires, all and all it's about the same. Is that about it?
Real bottom line answer - at some time I need to support the bike/rim industry and get a new bike that can handle 700 X 28mm tires. Is that about it?

A racing tire is a function of the rim width for maximum aero - the rim should be 105% of the width of the tire typically. Its confusing because different rim shapes produce different tire widths for the same size, ie 23mm tires measure 25mm+ on wider rims. 23-25mm tires seem to be the standard now on more recent aero rims in the 25-29mm range.

For training its just whatever your bike/wheel combo will accommodate as the max tire size. Run the biggest tire that fits your frame and wheel's internal width appropriately so you can run lower pressure and get a smoother ride.

It's not going to be a big difference in speed. I prefer 25mm for comfort. I use them on my narrow 4 year old Mavic Ksyriums and also on my wider rim deep section race wheels. 28mm is a bit big for the narrow rims and either 23 or 25 would be fine on the wide rims which already provide some extra air volume. Comfort trumps speed for general riding and especially where the speed difference is minimal. With appropriate pressure the wider tyres costs you nothing and may gain you something in terms of rolling resistance. Aerodynamically and depending on the wheel and indeed the bike fork/frame the 23 MIGHT be faster.

Aerodynamic drag "greatly" outweighs rolling resistance at race speeds. The faster the speed, the larger the difference since rolling resistance increases linearly while air resistance goes up exponentially with speed. The crossover point is at around 15-16 kph or around 10 mph.

Here is a graph from Schwalbe:

Not if we're just talking about the contributions of the tire and wheel. The tire+wheel contributes a small fraction of the aerodynamic drag of the bike+rider system, but the tire determines the rolling resistance for the system. A faster-rolling tire can sometimes result in improved overall performance even if it makes the tire+wheel less aerodynamic.

This.
Also, aerodynamics are different for front and rear and less relevant when drafting (but still highly relevant)