# 23mm or 25mm tires?



## GumbyN

what, aside from 2mm of width, are the differences?
does the 23mm offer less rolling resistance and preferred for race days?
are 25mm more flexy/supple due to width?
does one grip better in corners than the other?

i assume they both fit on the same size rim/wheel.
i have noticed that some bikes specifies which is the max size tire, they all seem to state 25mm.

i'm sure this will be another one of those, "depends on you" type things.


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## pmf

The number refers to the tire's height, not it's width. Theoretically, a 23mm tire should have the same rolling resistance as a 25mm tire (same model/mfg). Pro racers used to race 20mm tires thinking they were faster. Try even finding 20mm tires anymore. 

23mm tires are pretty much the standard. There's a few 25mm around, usually in basic black (no colors). I've always ridden 23mm tires and been fine with them. I'd think 25mm tires would give you a little more cushion which might be nice on bad roads. You could also run them at slightly lower pressure, which might feel more comfortable.


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## dysfunction

IME, it is.. and they are ... I never detected any difference in speed between 23's and 25's.. on the same bike. Comfort, thanks to lower pressure, yep.


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## Pablo

FYI, there are a lot of threads on this issue. It's an ongoing, hotly-debated topic.


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## AndrwSwitch

For me, the bottom line is that a 25mm tire will allow me to use lower tire pressure without getting pinch flats.

IMO, a lot of the 23mm vs. 25mm debate has more to do with tire pressure than the actual width of the tire. Any advantages a 25mm tire has are really advantages due to lower pressure (again, my opinion.)

If running your 23mm tires at a pressure that gives you a comfortable, efficient ride results in you getting pinch flats, try going up a size.


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## Mr. Versatile

25mm tires are indeed wider than 23s. They actually have LESS rolling resistance that the narrower tires. There are multiple technical, scientifically conducted studies/articles proving this. If you'd like, send me a personal message & I'll send some to you. 25mm are also more comfortable by, IMO, a significant margin, and they get better traction, and wear longer.

The down side is that they're heavier and therefore don't accelerate as well, or climb as well as narrower tires. More people ride 23mm tires than 25s by a very significant margin. Why? Several reasons. One is that many years ago people, including myself, believed that narrower tires were faster. Another reason is tradition, and yet another is appearance. Some race bikes have very tight clearances and have a hard time accommodating tires bigger that 23mm.


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## TWB8s

28's in the spring for me until I need to feel faster and then the 25's get mounted. I still have a few 23's on bikes but they don't get used so much so when they get old enough or get a cut they'll get replaced with 25's.

Oh, for me tires are Continental if the bike matters, Bontrager if it doesn't. I'll never ride a Michelin again.


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## AFenvy

Not all manufacturer's tires completely follow the specification either. Some 23s are really wide and some 25s are really narrow. I happen to have unusually narrow 23s on one bike and very wide 25s on another, so the difference is noticeable. But I have never tried them both on the same bike so I cannot directly compare them. I do feel the wider tires offer a more comfortable, smoother ride. They feel less agile ("darty") but that also means they don't get caught in small grooves etc. in the pavement as easily. It lends to a more stable feel overall, but honestly that probably has more to do with the kind of tire, rubber compound, etc than the width.


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## AndrwSwitch

My road bike came with 25mm tires, Continental GP 3000s, and I put on 23mm GP 4000s when I wore them out. I noticed that the 23mm tires felt a little more agile in both initiating turns and accelerating, but maybe there was an actual difference between the models, too. I didn't notice a change in comfort. At the time, I was still riding at 120psi. I ride with much lower pressure now. I weigh 160 pounds at the moment, and I feel like I get good handling and comfort, without pinch flats, at my current pressure.

My commuter gets larger tires, partly because they're the ones I happen to have around and partly because I typically ride it at least somewhat laden, and like the extra volume for that.


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## tihsepa

hell, i ride 33 smoohie folders. they weigh in at 288 grams and ride really good at 80 psi. the guys i ride with on their 23's are a litle bit jelous i am not working any harder than they rea at speed.
they ride great.


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## PlatyPius

Mr. Versatile said:


> 25mm tires are indeed wider than 23s.* They actually have LESS rolling resistance that the narrower tires. There are multiple technical, scientifically conducted studies/articles proving this.* If you'd like, send me a personal message & I'll send some to you. 25mm are also more comfortable by, IMO, a significant margin, and they get better traction, and wear longer.
> 
> The down side is that they're heavier and therefore don't accelerate as well, or climb as well as narrower tires. More people ride 23mm tires than 25s by a very significant margin. Why? Several reasons. One is that many years ago people, including myself, believed that narrower tires were faster. Another reason is tradition, and yet another is appearance. Some race bikes have very tight clearances and have a hard time accommodating tires bigger that 23mm.


Yay! Someone else who *knows*. I've been saying that since I joined RBR, but it seems that no one believes me.

As to the earlier comment about 700x25 tires not being available in colours.... you're looking in the wrong places. I can get all kinds of colours. I have brown 700x25 tires on my bike right now.


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## tihsepa

PlatyPius said:


> Yay! Someone else who *knows*. I've been saying that since I joined RBR, but it seems that no one believes me.
> 
> As to the earlier comment about 700x25 tires not being available in colours.... you're looking in the wrong places. I can get all kinds of colours. I have brown 700x25 tires on my bike right now.


i am with you. i think you would have to be nuts not to runthe largest, lightest tire available. comfy!


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## PlatyPius

A from Il said:


> i am with you. i think you would have to be nuts not to runthe largest, lightest tire available. comfy!


Yup. When I order my Cyfac Vintage Rando, I'm going to specify clearance for 700x32 tires with fenders.


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## wim

PlatyPius said:


> Yay! Someone else who *knows*. I've been saying that since I joined RBR, but it seems that no one believes me.


I've always believed that a certain brand/model 25 will have less rolling resistance than an identical brand/model 23 if you test the 23 and the 25 at identical tire pressure. There's no question about it. In simplified terms: tire tension (resistance to deflection) = tire pressure x tire volume.


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## Peanya

And the debate goes on. I'd bet that, given the exact circumstances (if that could possibly happen), the differences in rolling resistance over a 40 mile ride, might make a 30 second difference at most. But, I'd sure be a heck of a lot more comfortable, with less fatigue on the bigger.


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## CurbDestroyer

Since I started using (Conti GP 4000) 25c tires I've noticed less flats and more comfortable. As far as speed goes I haven't noticed a difference. With that experience I've decided I'm never going back to 23c tires. On my commuter even I went to (Conti Gator skin)28c tires, my immediate reaction was they had too much "Float" as I would put it. but I really like them. I recently went back to (Conti GP 4000) 23c because they are the biggest tire that fits on my fixed gear. They ride like bricks compared to what I was used to. I think 28c for training and commuting, and 25c for racing. The 25c tires handle better than 25c and give you better pinch flat resistance. 

I guess I'd go back to 23c tires if someone else was footing the bill.


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## CurbDestroyer

Peanya said:


> And the debate goes on. I'd bet that, given the exact circumstances (if that could possibly happen), the differences in rolling resistance over a 40 mile ride, might make a 30 second difference at most. But, I'd sure be a heck of a lot more comfortable, with less fatigue on the bigger.


 Suppose your right, but what good are those 40 seconds. In 40 mile group rides I'm riding along with the group. In a race I'm riding along with the group. and when I train I probably waste more time waiting at stop signs, and other traffic. So the question is, when will see those 40 seconds? I guess if I'm in a Time trial I suppose. 

My point is I see some people agonizing over which tire to choose from, but the difference will never be realized because for 99% of there rides they are riding with other people, or training by themselves. Also if you get dropped from the group, look at it this way, do you think it was because your tires were 2mm too wide?


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## Kerry Irons

*Say what?*



pmf said:


> The number refers to the tire's height, not it's width.


Short of claiming that 25 mm tires are made that way by adding 2 mm more tread thickness to a 23 mm tire, could you please offer any plausible explanation of how a basically round structure (the tire will go to a round shape anchored by the rim sidewalls) could be taller and not wider? I think you are seriously confused.


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## CurbDestroyer

Kerry Irons said:


> Short of claiming that 25 mm tires are made that way by adding 2 mm more tread thickness to a 23 mm tire, could you please offer any plausible explanation of how a basically round structure (the tire will go to a round shape anchored by the rim sidewalls) could be taller and not wider? I think you are seriously confused.


It might offer an answer. 









One day I was bored so I figure the difference between using a 23c and 25c tire. 








What does a 2mm difference make with 44x16 @ 80RPM? The 25c tire averages .08 Mph more, almost 1/10 Mph more with the same gear and cadence. Now I'm not saying 25c tire are faster, you will have to compensate for the larger wheel diameter.

I'm going to guess in real life . . . rather than paper . . . the two are almost indistinguishable.


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## wim

Peanya said:


> But, I'd sure be a heck of a lot more comfortable, with less fatigue on the bigger.


Yes, but only if you run the bigger tire at less pressure than you would the smaller tire. And when you do, there goes your bigger-tire rolling resistance advantage. 

Actually, your "30-second at most remark" (probably much less) is right on because at anything over noodling speeds, aerodynamic resistance is vastly more significant than tire rolling resistance. Much ado about not much, especially debating 23 versus 25.


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## Mapei

I used 23mm tires for ten years. Veloflex, cheap Vittorias, Continentals and Michelins. Six months ago I got some Vittoria Diamonte Pro 25's. 

Ironically, the new Vittorias demand I use higher pressure than the Michelins. With the Michelins I was running 90 psi. Vittoria demands I use a minimum of 100, and I'm using 105.

The 25's are slightly more impervious to road grooves and such, but I've still found myself in dire straits. Ride is slightly more comfortable with the 25's, despite the higher pressures. I have found absolutely zero difference in terms of acceleration, climbing, and other performance issues. The 25's fit into my Time frame, but just barely. If you have a Colnago, fuggetaboudit.

All in all, I'm happy with my 25's. Maybe it's just that the Vittoria Diamantes are wonderful tires in all sizes, but I can say that my experiment with the larger tires is a complete success.


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## GumbyN

Pablo said:


> FYI, there are a lot of threads on this issue. It's an ongoing, hotly-debated topic.


ah, thanks. 
as a former moderator of one of the largest cigar/pipe forums on the 'net, i should've known better and done a search (as i have for other things i've wondered about).

---
thanks everyone for the feedback, didn't mean to start anymore hotly contested debates.


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## Drew Eckhardt

pmf said:


> The number refers to the tire's height, not it's width. Theoretically, a 23mm tire should have the same rolling resistance as a 25mm tire (same model/mfg). Pro racers used to race 20mm tires thinking they were faster. Try even finding 20mm tires anymore.


Otherwise identical 25mm tires have less rolling resistance than 23mm at the same pressure because the short, wide contact patch deflects less for lower energy loss in the tire.

Past 25 MPH the wider tire becomes a net loss due to increased frontal area and the resulting aerodynamic drag.



> 23mm tires are pretty much the standard. There's a few 25mm around, usually in basic black (no colors). I've always ridden 23mm tires and been fine with them. I'd think 25mm tires would give you a little more cushion which might be nice on bad roads. You could also run them at slightly lower pressure, which might feel more comfortable.


When you weigh 145 pounds, you can run 23mm tires at 100-105 psi rear and 95 front for a nice ride without pinch flats.

At 185 pounds, the numbers become 110-115psi in back and 105psi up front which isn't nearly as pleasant. Switching to 25mm tires lets you have the same 100-105 psi rear and 95 psi front which you had in your 20s at a 145 pound cycling weight.

I switched to 25mm tires and don't plan on switching back unless I shrink another 40 pounds.


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## Pablo

A from Il said:


> hell, i ride 33 smoohie folders. they weigh in at 288 grams and ride really good at 80 psi. the guys i ride with on their 23's are a litle bit jelous i am not working any harder than they rea at speed.
> they ride great.


Make/model?


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## ZoSoSwiM

I went from 23's to 25's 2 years ago and felt a noticeably smoother ride immediately. I was more comfortable so in the end I was faster. I haven't ridden 23's since. However now that I've lost a bunch of weight I'm going to go back to 23's this time around and see if it changes how I feel.


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## seacoaster

For 2011 Cannondale is shipping 25 mm tires on their Synapses (their "plush" road bike). They used 23's in 2010.

I have 25's on my 2010 Synapse and love the ride. I'm 170 lbs. and running 85/95 psi (front/rear) and no pinch flats. The only downside is that it's very difficult to install or remove an inflated 25 on the rear, as there isn't enough clearance between the chainstays. Just remember to inflate it after it's on the bike.


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## Alaska Mike

I ran 23c and 25c tires the last few years, sometimes simultaneously on the same bike. Always liked the ride quality of the 25c tires (I run them 10psi lower than the 23c tires), but for a couple of my bikes clearance issues with the front fork kept me from using them front and back.

I still use 25c tires on my commuter wheelset (Open Pros), but have switched back to 23c tires on my race and training wheelsets, which have 23mm rims (Velocity A23s and HED Kermesses). With the wider rims I can still run the lower tire pressure for ride quality, and still retain or enhance control. I'm guessing wider rims will be seen more in the future from more manufacturers, since it seems to be the latest, greatest "innovation" in a while.


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## terbennett

pmf said:


> The number refers to the tire's height, not it's width. Theoretically, a 23mm tire should have the same rolling resistance as a 25mm tire (same model/mfg). Pro racers used to race 20mm tires thinking they were faster. Try even finding 20mm tires anymore.
> 
> 23mm tires are pretty much the standard. There's a few 25mm around, usually in basic black (no colors). I've always ridden 23mm tires and been fine with them. I'd think 25mm tires would give you a little more cushion which might be nice on bad roads. You could also run them at slightly lower pressure, which might feel more comfortable.


25s are wider than 23s. Have you ever seen a 700 X32? It's width. that's why when you get above 25, brake clearance becomes a concern.


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## mitchtaylorsbro

seacoaster said:


> For 2011 Cannondale is shipping 25 mm tires on their Synapses (their "plush" road bike). They used 23's in 2010.
> 
> I have 25's on my 2010 Synapse and love the ride. I'm 170 lbs. and running 85/95 psi (front/rear) and no pinch flats. The only downside is that it's very difficult to install or remove an inflated 25 on the rear, as there isn't enough clearance between the chainstays. Just remember to inflate it after it's on the bike.


I have that bike and love it. I weigh (insert a number considerably higher than 170) lbs. and run 105-ish psi, front and back. I recently fixed a flat rear tire and wondered why it was so hard to re-install. now I know 

Back on topic, after reading this far, I think I'll stick with 25c tires.


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## Salsa_Lover

25c are larger and then give you a more cushy ride, but they are heavier and have more rolling resistance than the 23c when inflated at normal use PSI. 

Why ? because off course the 25c have a lower recomended running PSI than the 23c ( hence cushier ), See the Continental chart posted before for reference.

If you would pump both tyres at the same PSI they would probably be very close in the comfort deparment, but a larger tyre at higher PSI has more probability of bursting. BTW that is why we use smaller tyres, the smaller the tyre the higher the PSI you can run them safely, hence the tyre will be harder and by consecuence less rolling resistance.

There is a long debate ongoing here about that here, but I think it depends on the use you want to give them.

If you want a tyre that can be inflated and at higher PSIs so less rolling resistance ( it is harder so less energy gets lost on the cushiness ) , for competitive riding or racing , then pick a smaller tyre.

If you want a comfort ride for sportive touring or commuting ( even century commuting ) pick a larger tyre and inflate it at lower PSI.


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## tihsepa

Pablo said:


> Make/model?


Jack Brown greens. i weighed them at the shop. slightly lighter than the 295g claimed.
where else are you going to get a smooth folder that size?


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## Peanya

Mapei said:


> I used 23mm tires for ten years. Veloflex, cheap Vittorias, Continentals and Michelins. Six months ago I got some Vittoria Diamonte Pro 25's.
> 
> Ironically, the new Vittorias demand I use higher pressure than the Michelins. With the Michelins I was running 90 psi. Vittoria demands I use a minimum of 100, and I'm using 105.


Demands? You can run a lower pressure than the minumum recommended. I don't know why they say you need 100+. My best guess would be that some people look for higher PSI tires because they think they'll go faster. I know this, because I used to think this too!


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## Mr. Versatile

Salsa_Lover said:


> BTW that is why we use smaller tyres, the smaller the tyre the higher the PSI you can run them safely, hence the tyre will be harder and by consecuence less rolling resistance.


Sorry, but this just isn't true. All roads have imperfections and texture to them. When tires roll over these it slows you down because of the energy loss from friction. When tires are pumped up hard they vibrate/bounce up & down when rolling over the imperfect road surface. Softer tires absorb the imperfections in the road surface. The difference is it takes more energy to move the bike up & down than it does when the tires absorb/deform over road imperfections therefore allowing the softer tires to roll with less resistance. Of course this is only true to a degree. If the soft tires are too soft they'll roll with more resistance because they distort too much internally (between the threads) in addition to giving a too large footprint. Tires that are very hard will roll with less friction on a perfectly smooth surface like a wooden track.


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## seacoaster

Peanya said:


> Demands? You can run a lower pressure than the minumum recommended. I don't know why they say you need 100+. My best guess would be that some people look for higher PSI tires because they think they'll go faster. I know this, because I used to think this too!


My Specialized tires are supposed to be inflated to a minimum of 100 psi, but they've never seen that much pressure. Tires haven't exploded, no pinch flats and my hair hasn't fallen out, so I guess I don't need as much pressure as Specialized thinks I do.


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## veloduffer

Schwalbe has a nice writeup on rolling resistance, particularly about narrow vs wide tires:

http://smtp.schwalbetires.com/tech_info/rolling_resistance

I ride 25mm these days - no discernable difference in performance.


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## Pablo

A from Il said:


> Jack Brown greens. i weighed them at the shop. slightly lighter than the 295g claimed.
> where else are you going to get a smooth folder that size?


I ride the Blues. Love 'em.


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## tihsepa

Pablo said:


> I ride the Blues. Love 'em.


yep, they are a really nice. i will never own a bike you cant get at least a 35 on.


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