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25s vs. 23s

Old 02-15-19, 03:03 PM
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This tire size stuff is also super dependent on rider weight.
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Old 02-15-19, 03:10 PM
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Trends are just self reinforcing , among, those who worry about such things ..

to have a definitive answer you need to work harder and survey a lot more people , get out that clipboard ..

Hows the cabin fever going, there?

Oh you're in LA .. Hope the mud slide doesn't move your house ..

good luck..


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Old 02-15-19, 03:37 PM
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And . . . brace yourself . . . it gets more complicated. With the newer tires a 25mm is no longer a 25mm. The Conti 4000, at 25mm, measures about 29mm wide on a modern wide rim. A Conti 5000, at 25mm, measures about 25mm on a modern wide rim -- less than that on an "old fashioned" narrower rim designed for 25mm fitment. In other words, a new Conti 25mm road tire is about the same width as last year's Conti 23mm tire.

Wider tires of the same construction offer less rolling resistance AT THE SAME PRESSURE. If you're riding TT's on smooth roads, you can't pump up a 25mm tire to the same pressure as a 23mm or a 21mm. So . . . for both aero and rolling resistance purposes, TT and triathlon setups are still going with narrower tires at higher pressures, even on wider wheels. The "hot" setup is a tire a mm or two narrower than the outside width of the wheel.

And if you compare your 23mm tire at 120 psi to your 25mm tire at 65 psi? The 23mm tire is going to be faster. But the 25mm tire is going to feel as if you've got suspension on the bike.
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Old 02-15-19, 03:59 PM
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Originally Posted by Maelochs View Post
i did an experiment on my Fuji Sportif, going form stock wheels and stock, lightly treaded tires to a set of light metal wheels with Conti Ulrasport II, to a set of light (about 1400 gram) carbon rims with Hutchinson Fusion 5s. The bike was noticeably more lively with the lightest gear---but I must have been saving almost a couple of pounds. Going from 28s to 23s, I might be saving a few hundred grams. Would I notice it? Possibly. Would the ride be more comfortable? Almost certainly. Would my overall average speed over a specific route given similar rest and nutrition be quicker or slower? I don't care because every ride is different anyway ... but also because i don't race. A tenth of a mile per hour over a 20 mile ride doesn't matter to me.

What each rider prefers is probably more important than the mathematical data which is only imprecisely recorded anyway, in most cases.

That said, i run 23s on three bikes, 28s on two, and 32s on another. if I want to feel like I am going fast, i ride the lightest bike with the skinniest tires. My actual average speed for the ride is a reflection of so many other factors, no valid comparison can be made. How it feels is basically how it is unless I am racing ... which i don't do.

So, as with so many things, the "right" answer for what tire and what pressure is "right" for any rider is totally dependent on what that rider believes it to be.
Interesting comments.

Last year, I went from 25c tires on my cross/adventure bike to 30c tires (Schwalbe G-1 Speeds) in anticipation of a tour with significant gravel riding we were planning in Norway. I mounted them up tubeless. I was quite surprised that my average speed on the same routes I normally ride was the same or even at times slightly faster than it was when riding them on my 25c tires. Thatís over about 500 miles of riding, so the that takes a lot of the variability out of it. So by going to a wider tire (admittedly, a light and supple wider tire), I had the no difference in speed but ride quality was better.

The 30c tires rode super plush and I had them pumpted up to around 65psi. My 25mm tires I pump up to around 90-100psi. Iím a lite clyde with respect to size and I can generate significant power. The 25c tires I had been riding were on an older set of Enve tubular carbon rims that weigh around 1200 grams for the set. The 30C tires were on a pair of HED Belgium+ hoops with Saphim bladed spokes with a wheel set weight of about 1450g. The tubeless tires were pretty close to a wash for weight with the tubulars I was riding.

Anyhow, imagine my surprise at seeing those average speed numbers. I attribute that to better suspension the 30c tires gives with respect to bumps and pavement defects. The added weight in the rim was slightly noticeable on some steep uphill climbs but not enough to make me want to go out and replace those wheels with a set of carbon ones.

As for ride quality, the suppleness of the tires was surprising to me. I really enjoyed the handling and the ride. We even rode them through a 30 mile rock garden in Norway that I should have ridden on a mountain bike.

So I think that it depends a LOT on the wider tire that you select. There are some tubeless tires that tend to ride like truck tires (especially older designs) and there are wider tires that are simply not aimed at the same kind of road riding that a training 25 or 23c tires is. But now that rims are wider and wider tires are being design for more performance riding, I think itís possible to get the best of all of it - performance (at least for enthusiast riding, maybe not racing) and ride quality.
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Old 02-16-19, 06:45 PM
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