# 23c vs 25c



## fishman473

What are the advantages and disadvantages of 23c versus 25c tires for endurance riding?

My assumptions are that 23c is lighter, but 25c will roll a little smoother and perhaps less rolling resistance, or more grip in sketchy conditions?

I'm 170 lbs now, hoping to get down to 155, mostly concerned about performance for metrics+ (thinking of doing a triple-metric later this summer), other than that its casual afternoon rides, light training, etc. I don't race on the road anymore, but I might pick up a few crits in the spring, but not really a factor in how I choose components. Roads here are all paved, no gravel within 50 miles so also not a factor. I usually just get what I can find for a good deal at the bike swap, but wearing tires out mid-season, looks like I could take my time and pick the 'right' tire this time.


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## pulser955

I do a few 6 or 7 hour rides a month and my bike of choice for them has 23s. I have 25s on the other bike but that's just because I use it for bad weather and riding to work. I cant fit 25s on my fast bike the chain stays are just too tight. But I don't mind I like 23s allot more. I find them to be faster. I know lots of people will tell you 25s are faster. But my experience has been the other way.


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## Jwiffle

Advantages of 23c:
*lighter weight
*if you are riding outside your normal area and need to replace a tire, more likely to find a high-end 23 in stock at a local shop than a 25 since they are the "standard" size

Advantages of 25c:
*more comfortable
*better traction, cornering
*can run less air pressure to achieve the above with less fear of pinch flatting
*no slower than 23 in my experience (and several tests I've read claim they are faster)


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## ScottsSupersix

As others have said, I ride 25s because of better traction in wet and during cornering. I will say that I am sure they saved me when my rear tire slid sideways on a small patch of water on a downhill at 41mph with an abrupt crosswind. Not only that, but I can hit potholes and road cracks and retain stability much more than I could previously on my 23s. I weigh 180lbs, ride on 23mm HED C2 rims, and the 25s work great for me.


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## jorgy

Any particular 25s you all like? I had already been planning on ordering a pair of Vittoria Open Corsa Evo CXs in 25s when my current tires need to be replaced.


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## ScottsSupersix

Continental GP 4000s. I hear Vittoria's ride great, but I have also heard they wear out fast and puncture easily. I am curious to hear about other rider's experiences, as I have never tried them. If you have great roads and don't ride in the country like I do, they might be a great choice. The thought of shredding a tire far from home does not appeal to me.


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## pulser955

jorgy said:


> Any particular 25s you all like? I had already been planning on ordering a pair of Vittoria Open Corsa Evo CXs in 25s when my current tires need to be replaced.


I ripped open a Vittoria Open Corsa Evo CX in only 3 rides. When the Vittoria rep looked at it he told us it was really a race day only tire.


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## Dajianshan

The best tires I have ever ridden where Conti GP 4000 25c. I have 23c now due to availability, but I really liked the 25c. I think I put 10,000miles on them before the rear tire finally suffered a tear. Now I have Conti Force 24c on the back because I needed something in a pinch. I like GP better.


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## 251

I'm currently on my second pair of 25mm Open Corsas. The first set were the newer 320 tpi tyres, and the current are the older 290 tpi version. I weigh 72kg, inflate them to about 90/95 psi (f/r), and use them for normal road riding with a little gravel/hardpack mixed in.

They've been great tyres, and have the best ride of any road tyre I've ridden, but I think I'm going to try the 24mm Vittoria Diamante Pro Radial next just to see how they compare.

The first set lasted around 3000 km until they started getting frequent punctures, but I didn't track the usage very closely. The current pair have been on for 1019.2 kms. So far, no punctures and no problems. The front is showing minimal wear, and the rear is showing wear in the center, as you'd expect (front on top, rear on the bottom):


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## porttackstart

Take a look at the Michelin Pro Optimums. They are 700x25 and I have been very happy with them on my bike. I've been using them for both training and racing. They are designed as a pair so that they wear equally.


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## heathb

If you're training I would use a Conti Gatorskin. I've used the 25cc for my daily training tire for several years now. If you're riding a lot miles over varied terrian I even make my own tire liners out of Fedex mailing envelops, the stuff that uses DuPont Tyvek. With this combo I have a fairly light tire that holds up very well to sharp rocks and other stuff that might interrupt my ride.

For me I won't go back to riding anything smaller than 25cc, because the ride is just too harsh and I haven't noticed any drop off in speed.


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## Alleywishes

I actually rode with 24c Duro Fixie Pops on my old fixed gear... When I got my new road bike, my friend begged me not to put them on... When I get a little bit more smackers, I'm going to get a pair.


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## AndyMc2006

I have been riding Michelin Krylion 25's and liked them a lot, smooth ride, comfortable and minimal flats. They have been discontinued but you can probably find them online if you look. I am now running the Michelin Pro 4, its lighter and seems a little wider, definitely comfortable. I doubt they will last as long as the Krylions. I was going to buy the Pro 4 Endurance but they were not in stock when I ordered them. They are a little heavier but they cost less and will probably last longer.


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## dspiel

just fyi the Pro 4 Endurance and Michelin Krylions are almost the same tire with the difference being the endurance is the newer improved version supposedly.


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## aclinjury

I will be interested reading any website presenting data showing conclusively that 25 roll faster than 23. If that is the case, then would 28 roll faster than 25? and 32 roll faster then 28? and the peloton would be wise to ride a 32 on every flat course?


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## heathb

aclinjury said:


> I will be interested reading any website presenting data showing conclusively that 25 roll faster than 23. If that is the case, then would 28 roll faster than 25? and 32 roll faster then 28? and the peloton would be wise to ride a 32 on every flat course?


No the 28cc and bigger is when you start noticing the weight of the tire. I use 28cc on my commuter cyclocross bike and they roll fast enough, but they add more weight and I can tell they are a little sluggish when accelerating. However they sure help to soak up the bumps and cracks in the road and they last a long time. Of course I've got heavy conti touring tubes in those 28cc tires as well, so that adds weight. Most road bikes don't have the clearance in the forks or chainstays for tires bigger than 25cc.


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## wim

aclinjury said:


> I will be interested reading any website presenting data showing conclusively that 25 roll faster than 23. If that is the case, then would 28 roll faster than 25? and 32 roll faster then 28? and the peloton would be wise to ride a 32 on every flat course?


Many popular web sites and books geared to the general public make that claim. But what many of them neglect to mention is the fact that a larger tire will have less rolling resistance than a smaller one _only if they both are inflated to the same pressure_. Since no one inflates larger tires to the same pressures as smaller ones, the claim (as you correctly suspect) is bogus in the context of bicycle performance. To turn it around: if you run a test and find that a larger tire has less rolling resistance than a smaller one, than either the smaller tire was underinflated or the larger tire was overinflated.


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## Mike T.

pulser955 said:


> I ripped open a Vittoria Open Corsa Evo CX


That's hardly a fault of that brand of tire. I have three years on those tires and just three flats - none from tread or sidewall penetration. No tread cuts either.



> When the Vittoria rep looked at it he told us it was really a race day only tire.


Not from my findings. For me they're a top end everyday tire. Life's too short to ride low end tires.


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## nOOky

Be aware that some 23mm tires are closer to 24mm, and some 25mm tires are also closer to 24mm 
Also consider rim width in the equation, you don't want a wide tire on a narrow rim or a narrow tire on a wider rim etc.


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## pulser955

Mike T. said:


> That's hardly a fault of that brand of tire. I have three years on those tires and just three flats - none from tread or sidewall penetration. No tread cuts either.
> 
> 
> Not from my findings. For me they're a top end everyday tire. Life's too short to ride low end tires.


I have never been a fan of Vittora any way. I like the Vredestein fortezza tricomp quattros. They are the best tire I have ever ridden.


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## Mike T.

nOOky said:


> Be aware that some 23mm tires are closer to 24mm, and some 25mm tires are also closer to 24mm


And my 28mm Conti 4-season are narrower (actually measure 25mm) than my 25mm Vittoria Open Corsa Evo CX (actually measure 26mm) so I dunno *what* it all means.


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## laffeaux

aclinjury said:


> I will be interested reading any website presenting data showing conclusively that 25 roll faster than 23. If that is the case, then would 28 roll faster than 25? and 32 roll faster then 28? and the peloton would be wise to ride a 32 on every flat course?


Take a look at the results found here:
Bicycle Quarterly: Performance of Tires | Off The Beaten Path

At some point a wider tire will become slower due to increased rolling resistance and weight (on climbs). But I'm not sure anyone is really knows where that occurs.

I just finished a long (700+ miles in 8 days) ride on 38mm tires. Before the ride I was concerned that the extra width would slow me down. However, I had no issue at all keeping up with riders on 23 and 25mm tires. By the 3rd or 4th day I decided that any "disadvantage" that I had due to the extra weight during climbing was more than offset by the extra comfort of the wider tires - my butt seemed to be less sore than others, and when the pavement was crappy I continued at the same speed while others slowed down.

For long multi-day, I'd say that narrower tires are at a disadvantage because comfort is much more important to continued speed. I'd likely opt for 23-25mm tires on a one-day ride (especially if there were lots of hills), but I'm not sure that a wide tire really has any disadvantages on a flattish ride.


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## kg1

*Wide Tires Won't Slow You Down*

I ride the Vittorias that you are considering, and they are the most comfortable tire I've ever been on. I used to ride the Conti 4 Seasons in 25mm exclusively (German engineering and all). The Vittorias roll more smoothly, to the point where I noticed it almost immediately. The new tires were the only change to the bike, and I was running them at the same pressure I run all my tires -- 100 front/110 rear. I haven't had a flat with these tires after about 1500 miles, but the roads I ride on are very good roads, so flats have never been much of an issue for me. The rear tire is showing wear after about 1500 miles and has squared off, but we have a lot of hills and I'm 190. You may see less wear if you are lighter or don't have a lot of hills to get over. I will buy these tires again. 

I ride brevets with a guy who rides 38mm tires at very low pressures on the brevets, and he swears by them. He also has a bike that he has 25s on. He seems just as fast on the 38s as he is on the 25s. In both cases, I'm struggling to keep up.

Good luck with your search.

Thanks.

kg1


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## captain stubbing

aclinjury said:


> I will be interested reading any website presenting data showing conclusively that 25 roll faster than 23. If that is the case, then would 28 roll faster than 25? and 32 roll faster then 28? and the peloton would be wise to ride a 32 on every flat course?


it also depends on the smoothness of the roads you are riding, a wider tyre with lower pressure will be smoother and faster if the roads are particularly rough. that is why people will let air out of their tyres when they take their vehicles off-road.


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## Eretz

Great thread and talking points. I ride Continental Gatorskins and 4000S black chili. I can get 3,000 miles out of a set of these easily at 90 psi. I've ridden other brands in 25mm but really enjoy the overall handling on every type of terrain the Continental's offer. In 25mm they're very light too [folding bead].

-Take into account rim width [check]

-Take into account terrain because a narrower tire for some conditions could leave you stranded [check]

-Lower tire pressure [usually 90 psi] on a 25mm can allow greater traction and better control on uneven or washboard conditions [you'll have more road contact, less bounce and ride faster]

-Some tire manufacturers misstate their tire sizing [Continental 4000S are 24mm not 25mm]-aclinjury

-Most riders train with heavier tires and race lighter [pendent conditions]


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## dlhillius

I used to ride Conti 4000's 23mm's on Stans which 'widen' them to almost 25mm at 95psi/105psi and they feel quite nice. I recently built a set of carbon tubulars that I've been spending more and more time on....glued up a set of Conti Comp 25's and talk about plush. WOW. Recently rode a double century on them and felt quite good afterwards. 

Either size has it's advantages and disadvantages, especially if you choose tubulars. My opinion....buy the best you can afford and what suits your needs and wants. I'm a distance rider so comfort matters.....I'm sticking with my 25's on the carbons for a while.


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## hdbiker

I doubt the controversy regarding speed with 23 and 25 will ever go away. One thing is certain, Gatorskins wear very well. I currently have over 4000 miles on a rear size 25 Gatorskin. It's starting to show that flat edge, but so far no thread. I usually would change it now to avoid a flat on the road, but I think I'll keep going to see how many miles I can get.


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## brewster

I have both 23 and 25s in various brands and models. I do notice a slight difference in acceleration up inclines most likely due to the heavier rotational weight. I don't notice any difference in flat line speed. The 25s in any brand are definitely smoother and seem to last longer before wearing out.


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## CBS78

Think tire design can impact things much more than small size differences. I switched from stock specialized espoir sports to Michelin pro3's and the difference in comfort and traction was very noticeable. Size isn't everything just a small factor.


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## gordy748

Having recently done a century on FMB Competition 25s, I can confidently say that the more comfortable the tire the much, much faster you will be riding from mile 70 through 100.

Initially I latched onto a train going 25 mph on the flat. They stopped and I kept going, eventually some of them caught up to me. They dropped me at about mile 60 and I caught them about mile 70. We were all cooked but they were on racy carbon bikes with 22 - 23 mm tires. They felt like they were being beaten up. While me on my ti bike, I could keep a relatively higher speed through the end.

25mm and ti is probably not my first option for a criterium, but definitely over distance...


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## Vibe

I have 28s on the front and 23s on the rear because of the wheel - weird setup. 

OT: Can I use a 28c tire on a 23c wheel (are wheels specific like that)?


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## Mike T.

Vibe said:


> I have 28s on the front and 23s on the rear because of the wheel - weird setup.


Why is that?



> Can I use a 28c tire on a 23c wheel (are wheels specific like that)?


There are no "23c" wheels. Yes there are different width rims (as there are different tire widths) but all rims, that I'm aware of, will take tires of all widths - from 19mm wide tires (silly narrow) to ones over 30mm. The limiting factor will be the tire clearance of your frame and fork. For instance, the Mavic Open Pro rim, originally designed for 23mm wide tires will work fine with 32mm wide tires - and maybe wider.


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## love4himies

hdbiker said:


> I doubt the controversy regarding speed with 23 and 25 will ever go away. One thing is certain, Gatorskins wear very well. I currently have over 4000 miles on a rear size 25 Gatorskin. It's starting to show that flat edge, but so far no thread. I usually would change it now to avoid a flat on the road, but I think I'll keep going to see how many miles I can get.


I have about the same on mine but think I'm going to be changing them soon. They have been very good to me.


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## Matthew Siow

My Specialized Roubaix Elite came with 25s originally but I've since switched to Continental 4000s GP 23s. The most obvious difference is it rolls smoother and speed. I've been riding with 23s since and that's 3 years now.


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## Vibe

Mike T. said:


> Why is that?
> 
> 
> There are no "23c" wheels. Yes there are different width rims (as there are different tire widths) but all rims, that I'm aware of, will take tires of all widths - from 19mm wide tires (silly narrow) to ones over 30mm. The limiting factor will be the tire clearance of your frame and fork. For instance, the Mavic Open Pro rim, originally designed for 23mm wide tires will work fine with 32mm wide tires - and maybe wider.


Ah gotcha. I'm a noob and my bike came with 28c tires. The rear wheel is a wheel with a power tab hub that I borrowed from a friend and has 23c tires.


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## Mike T.

Vibe said:


> Ah gotcha. I'm a noob and my bike came with 28c tires. The rear wheel is a wheel with a power tab hub that I borrowed from a friend and has 23c tires.


That wheel will take your 28mm tire.


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## M Ice

Just went to 25's a few weeks ago. Was riding 23 Gatorskins prior. Have ridden about 300 miles in the 25's and love them. Roll up quickly .... No issues with rolling resistance at all... Believe them to have less rolling resistance than the 25's with greater comfort. Don't really notice a difference on climbs.


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## albert owen

I honestly cannot tell the difference between 23s and 25s or the differences between different brands as far as rolling along and comfort are concerned The only issue for me is puncture protection - in this regard Vittoria and Continental get my vote.


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## MTBMaven

I recently heard that 25s were the thing because they were actually more aero. Had something to do with breaking the wind and creating cleaner air flow over the bike. Same principal as the wider rims on the market these days. In the end who knows, could be a bunch of malarkey. 

I just went back to GP4Ks in 23 after two sets of 25s. Honestly I couldn't tell much difference in ride quality but the 23s feel quicker. I ride the same air pressure in both - ~100psi. Could be placebo.


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## DionSF

What are opinions on running 23s in front and 25s in back (Contis GP4000s)?


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## captain stubbing

I just went back to GP4Ks in 23 after two sets of 25s. Honestly I couldn't tell much difference in ride quality but the 23s feel quicker. I ride the same air pressure in both - ~100psi. Could be placebo.[/QUOTE]

think u missed the whole point, u should run the wider 25 at lower pressure (about 10 less) than the comparable 23s.....no wonder u didn't notice any difference!


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## captain stubbing

DionSF said:


> What are opinions on running 23s in front and 25s in back (Contis GP4000s)?


run this exact setup, no problems.....will only make a relatively minor difference that your butt may or may not notice.


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## dlhuillier

23 for sure.


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## dlhuillier

23 for sure.


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## flatsix911

MTBMaven said:


> I recently heard that 25s were the thing because they were actually more aero. Had something to do with breaking the wind and creating cleaner air flow over the bike. Same principal as the wider rims on the market these days. In the end who knows, could be a bunch of malarkey.


Recent research by carbon wheel manufacturer's has shown a significant advantage to matching 25mm wide rims to 25mm wide tires for maximum aero benefit. :thumbsup:


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## aclinjury

flatsix911 said:


> Recent research by carbon wheel manufacturer's has shown a significant advantage to matching 25mm wide rims to 25mm wide tires for maximum aero benefit. :thumbsup:


This is still a mix results.

1) Some tests show that this benefit would only occur if the pressure of the 25c tire is kept relatively high. But many people buy 25c with the desire to lower the pressure for a softer ride, in this case the aero bebefits is not so great if at all

2) The latest series of aero wheels, e.g. Zipp Firecrest, Bontrager Aeolus D3, Mavic (I forget the exact series), HED Jet series,.. they are optimized with 23c tires, not 25c. And all of these rims range from 23mm - 27mm at the brake track. So it is certainly NOT the case of matching a wide tire with a wide rim at all.

3) a lot of these tests are done on tubular tires. For clinchers, the results are not so conclusive. However, in Bontrager's white paper for their Aeolus D3 where they test some tubulars and clinchers, I remember reading that one of the best performing wheel is their 70mm Aeolus D3 CLINCHER wheel (beating out their own 70mm tubular version!).

3) Aero wheel has become so specialized now that some of these big wheel companies also recommend their OWN tires or a SPECIFIC tire in order to realize the maximum aero benefit. This is due to how each different tire interact with the rim to create the resulting air foil that would happen under such rim/tire interaction profile. Hence tire specificity is not to be ignored if your goal truely aerodynamic. Mavic recommends their own tire because they have put small little channels into their tires (on the side) and these little channels in the tire will somehow "tunnel" the wind smoothly over to the rim (ie, the airl foil transition from tire to rim will be as smooth as possible). This is not to say other tires won't benefit from the aero rim though.

So while the results in general do show that wider rims offer better aero, it's far from conclusive to say that 25c is more aero than 23c. If 25c were more aero, then Zipp, Bontrager, HED, Mavic would be optimizing their wheels for 25c, and not for 23c.

My take on the 23c vs 25c is this. Buy 25c if you wish to get a more comfortable ride (a little more, don't expect commuter bike comfortable). If you're a big guy (over 180 lbs), then get 25c. Other than this, 23c is perfectly fine. If you're thinking of getting 25c because you want "aero", well it's not gonna get you that advantage like you think.


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## marinman39

25's are great for anyone who is riding long, on a variety of road types and under various weather conditions. And yes, Continentals. Gatorskin if you really hate changing flats and want the longest wear. 4000's for the best ride in the world, great light weight. Been said by others, I am just seconding.


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## type36

Am having this same discussion with myself about tires, 23 vs 25. I just bought a bike with 19mm wide Topolino c19 wheels. I would kinda like to run 25's for the comfort, but worry that they are too wide for the rim, or may cause problems with brake clearance when being removed/installed.

I read here that the GP4000s (am leaning towards them) in 25 are actually 24mm wide......... maybe this is the way to go? Sooooo many choices.


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## RRRoubaix

Along w/ Mike T and 251, I'm a huge fan of Evo Open Corsa CX's. Fast, light and comfy. I do mostly relegate them to summer riding though. For fall and spring riding, I love the Open Pave's, and live out my cobbled fantasies.
Winter commuting and some training is usually on Gatorskins.


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## dnice

Implications of Rim Width - Slowtwitch.com

I have swapped between vittoria rubino pro 25s and gatorskins 23s, and i can tell you that i love, love the gatorskins. 

the above article provides some food for thought. we should probably be riding 25s on most of the wheels that come with the typical off the shelf road bike.


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## twinpuller

I have 23c tires on my look 566 and my wife has 25c on her giant ocr c1. Honestly can't tell much of a difference between the two except that I could run lower psi on her bike and feel more stable.


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## ScottsSupersix

Actually, a 25mm tire with lower psi equals more comfort and is also more stable, which is a huge difference, at least for me. I roll 25s on my Zipps to give me an edge on turns in gravel or water, as well as a fighting chance against deep road cracks, also increased comfort on rides of 3 hours or more. I weigh 190lbs, so lighter riders may not have the same experience.


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## T0mi

Jwiffle said:


> Advantages of 23c:
> *lighter weight
> **if you are riding outside your normal area and need to replace a tire, more likely to find a high-end 23 in stock at a local shop than a 25 since they are the "standard" size*
> 
> [...]


Totally irrelevant. Your bike won't explode if you ride mismatched tires. If you are really concerned about it, it's easier to buy at least one spare tire in advance and carry it in a bag. Especially if you consider that rear and front tires don't wear at the same speed.

Good folded tires do not take a lot of place :









25c is the obvious choice for endurance with race bike frames. 

28mm is even better if frame allows it. The gain in comfort definitely counter the loss coming from an higher weight once you have spent 4+ hours on the saddle. Speed comes a lot with feeling good on your bike.


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## T0mi

Jennifer3 said:


> If you are riding on the flats and you want t ride fast go with th 23. If you are riding in the hills and you are either heavy or you want to spear your legs go with the 25


I don't follow your logic. Being lighter, a 23 tire would be more appropriate for climbs while with a 25mm tires would ride as fast as a 23 in the flat.

All in all, the difference is so minimal it doesn't make a huge difference. The construction/quality variations between 2 brands/models makes for a bigger difference.


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## T0mi

marinman39 said:


> 25's are great for anyone who is riding long, on a variety of road types and under various weather conditions. And yes, Continentals. Gatorskin if you really hate changing flats and want the longest wear. *4000's for the best ride in the world, great light weight*. Been said by others, I am just seconding.


You have clearly not tried veloflex open tires.

As much as I like gp4000s, they are very far from the suppleness of a 22mm open corsa, even in 25mm size. And veloflex now produce the open corsa/master in 25mm size weighting the same as a 23mm gp4000's.

That said I would agree the gp4000s is probably the best compromise if you take into account all parameters involved (rolling resistance, durability, puncture resistance, comfort, grip). As nice as they are, the veloflex wear very fast and do not offer the same puncture resistance.


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## T0mi

Matthew Siow said:


> My Specialized Roubaix Elite came with 25s originally but I've since switched to Continental 4000s GP 23s. The most obvious difference is it rolls smoother and speed. I've been riding with 23s since and that's 3 years now.


I don't think your very limited experience as any relevance.

Were the original tires in 25c size the same gp 4000s model ? if not, you can't draw any conclusion as the conti gp4000s are one of the fastest rolling tire produced. You may had the same experience switching from a <cheap oem tire> in 25mm to a 25mm gp4000s.

Did you figured the supposedly better rolling speed with a powermeter or feeling ? If we based on feeling like all racers were doing 25y ago, we would still be inflating our tires at 150psi. Without actual data from a powermeter on the same route at less than 2h interval you can hardly figure if tire A rolls better than tire B. Placebo effect is bigger than the real crr of a tire.


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## CO500

I run 25's less road slam than 23's and agree they are more comfortable that 23's.


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## drodrigueznyc

25s all the way... started with 23s which came on the bike.. it was ok till i started getting flats.. decided to upgrade to better, flat resistant tires and it was ok but i didn't feel comfortable with them.. it was a little rough due to the thicker flat resistant compound. this affected my confidence in my ride and caused me to slow down and zig zag a bit more than i wanted...felt like i was going to crack the fork. obviously i'm exagerating but the thought was always there...

i then read about how moving to 25s would make a huge difference and tried them out.. purchased a set of gp4000s and have not looked back since... smoother ride, nice flat protection and you can't really see a huge difference from the 23s.


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## mann2

I run GP4000s' 23c Front and 25c rear. tried both 25c's but noticed they felt slightly heavier and a bit harder to spin. they bounce better though and are more comfortable. running them staggered is a good compromise, i think.


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## Herbie

I can't tell any significant difference between 23s and 25s if you are comparing apples to apples, i.e. the same brand and model. When I get to 28s that's when I can start to feel the difference. 

Someone mentioned earlier, that wider tires only roll faster if they are to the same presure as thiner ones. I cannot point to the web site, but this is contrary to what I have read. The theory being that wider tires at lower presure deform and roll over obsticles and rough pavement rather than bouncing over the rough spots. I also have read that the difference in rolling resistence is not enough to make any practical difference so the only real reason to use wider tires is comfort from the lower preasure


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## Sisophous

Huge difference for me between 23 and 25. I got four "pinch" flats in less than 4 months with the 23s soon after buying my new bike. A couple years ago I bought the 25s and not only is the ride smoother and faster but I have not had a single flat. I also learned that running on less pressure makes for a better ride. I used to fill my tires to 120psi, the max, but now I run them at 90-100 psi.


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## Damon_Faulkner

Simply put, 23s are lighter and faster but 25s are more comfortable and could possibly make you use less energy through fighting vibration. Just depends on the type of ride you are going to do.


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## Local Hero

lol

what about 23/25 tires? 

Specialized Bicycle Components

_The Roubaix is an Endurance Road tire for epic rides from smooth country roads to rough field roads. The Roubaix is fast like any competitive road tire, but features unique casing technologies for added comfort and puncture protection. The 23mm tread handles quick. The 25mm casing smooths your ride and keeps you fresh. Slick center tread for low rolling resistance, shoulder sipes for increased surface adaption and grip. This tire is a game changer._

Casing: Endurant 120 TPI
Bead: Foldable
Center Compound: 70a / Shoulder Compound: 60a
Flat Protection: Endurant Casing and BlackBelt
700 x 23/25; psi 115-125; approx. weight 260g
700 x 25/28; psi 115-125; approx. weight 300g


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## ScottsSupersix

Just as an update, I have now switched to a 23 front and 25 rear, GP4000S. The front is now more sensitive over deep road road cracks and especially train tracks or concrete expansion channels, which we see alot of here in Texas. As long as you pull up and lift or jump your front tire over these channels, the rest is fine. I run both tires at 110lbs, which seems to work out well for my 190lb frame and Zipp 404 Firecrest wheels.


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## Luis Leon

*Going back to 25s*



Sisophous said:


> Huge difference for me between 23 and 25. I got four "pinch" flats in less than 4 months with the 23s soon after buying my new bike. A couple years ago I bought the 25s and not only is the ride smoother and faster but I have not had a single flat. I also learned that running on less pressure makes for a better ride. I used to fill my tires to 120psi, the max, but now I run them at 90-100 psi.


Same as above for me... 3 pinch flats (in less than 3 months, the first one on my first ride on my new bicycle). I do weight 185 pounds so maybe that is a factor. Just switched to 25s and will be riding them. Having previously ridden 25s on my aluminum road bicycle, I know what to expect... longer rides with less flats. I'm a recreational rider so any speed loss, increase rolling resistance, etc. between 23s and 25s is inconsequential to me.


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## Zeet

laffeaux said:


> Take a look at the results found here:
> Bicycle Quarterly: Performance of Tires | Off The Beaten Path
> 
> *At some point a wider tire will become slower due to increased rolling resistance and weight (on climbs). But I'm not sure anyone is really knows where that occurs.
> *
> I just finished a long (700+ miles in 8 days) ride on 38mm tires. Before the ride I was concerned that the extra width would slow me down. However, I had no issue at all keeping up with riders on 23 and 25mm tires. By the 3rd or 4th day I decided that any "disadvantage" that I had due to the extra weight during climbing was more than offset by the extra comfort of the wider tires - my butt seemed to be less sore than others, and when the pavement was crappy I continued at the same speed while others slowed down.
> 
> For long multi-day, I'd say that narrower tires are at a disadvantage because comfort is much more important to continued speed. I'd likely opt for 23-25mm tires on a one-day ride (especially if there were lots of hills), but I'm not sure that a wide tire really has any disadvantages on a flattish ride.


Actually, heavier tires will only help to maintain your speed, once you've established it. However, whenever you wish to speed up or slow down, tire weight can only impede your efforts. It's really all about inertia.

Therefore, to sum it up...

Whenever you wish to change your speed, a heavier tire will take more time to make that change. That's whether you're trying to either speed up, or slow down. Increased weight helps you either going downhill or on the flats, but hinders you whenever going uphill, or stopping.

_* Usually wider tires means more weight_


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## SkiRacer55

Kind of my take on the whole thing, too. I've always subscribed to the theory that the most important place to take weight out of a bike is in the rims and tires for the reasons Zeet discusses. I'm fairly heavy, so it's important for me to have a setup that climbs well and accelerates quickly. I've always used 23s, and I'm probably going to stick with them. My current favorite ride is a 2012 Specialized Roubaix Pro SL3 frame that I built up with SRAM Force and Boyd Vitesse wheels, which have a deep (28 mm) section that provides a good interface with the tire. I also have a 2008 Roubaix with wheels with Mavic CXP22 rims that have 23 mm Conti GP4KSs. I've always used Conti, but for the Vitesse wheels, I went with Michelin Pro3 Service Course, and they're definitely more pliable, tackier, and more comfortable than the GP4KSs. Between the wheels, tires, and frame on my 2012, I'm plenty comfortable, and the bike accelerates and handles like my Nissan 350Z...






Zeet said:


> Actually, heavier tires will only help to maintain your speed, once you've established it. However, whenever you wish to speed up or slow down, tire weight can only impede your efforts. It's really all about inertia.
> 
> Therefore, to sum it up...
> 
> Whenever you wish to change your speed, a heavier tire will take more time to make that change. That's whether you're trying to either speed up, or slow down. Increased weight helps you either going downhill or on the flats, but hinders you going uphill.
> 
> _* Usually wider tires means more weight_


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## Fai Mao

wim said:


> Many popular web sites and books geared to the general public make that claim. But what many of them neglect to mention is the fact that a larger tire will have less rolling resistance than a smaller one _only if they both are inflated to the same pressure_. Since no one inflates larger tires to the same pressures as smaller ones, the claim (as you correctly suspect) is bogus in the context of bicycle performance. To turn it around: if you run a test and find that a larger tire has less rolling resistance than a smaller one, than either the smaller tire was underinflated or the larger tire was overinflated.


Actually the test for rolling resistance, at least the ones I've seen, at with tires at the same pressure. 

The difference is in the way the sidewalls flex and the shape of the contact patch not the pressure of the tire.


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## Kristatos

What I haven't seen yet is much in the way of discussion regarding speed and tire width - in that speed will obviously impact which tire rolls better. From having run 25s on my race bike that past year I sense that 25s have advantages at lower speeds, but that 23s are possibly better at high speeds. Where the tradeoff is I am not sure in terms of MPH, but I find that 25s lend to a smoother ride on uphills and flats, with 23s being faster on downhills. 

This makes sense to me as a tire with lower inflation will tend to heat up more relative to a high-inflated tire at high speed, and I think the whole point of 25s is to run lower PSI, otherwise it's just a bigger tire and you lose the advantages of better suppleness over rougher pavement. 

Also, I think of the situation of a gravel road section. At very low speeds you will notice huge differences in ride-ability between large soft tires and narrow firm tires, with the larger tire being the better ride. However, as you ramp up speed this difference also starts to go away. I've crossed short gravel sections in races at speed on rock-hard tubulars in years past just fine - the faster you crossed a short section of gravel the better as your wheel/tire didn't "sink" into the gaps between rocks. 

Anyways, I don't really put much stock into the tire testing I see so far in terms of the 23 vs 25 debate - there are too many variables. For endurance riding I think the 25 is the better choice overall, as typically people will sit up a little on downhills. For racing I am still not 100% sure. All of my sanctioned races this year have been on 25s and I never felt they held me back, and at times I feel I have better grip and can corner harder than many of the other riders. In a mass-start race I don't have issues with carrying speed downhill as I am drafting in the pack. I guess I still lean to the 25s but maybe in a road race with lots of climbing where I expect the group to blow up and not be riding in a large pack I'd possibly go with 23s for the faster downhill sections.


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## davidka

type36 said:


> Am having this same discussion with myself about tires, 23 vs 25. I just bought a bike with 19mm wide Topolino c19 wheels. I would kinda like to run 25's for the comfort, but worry that they are too wide for the rim, or may cause problems with brake clearance when being removed/installed.
> 
> I read here that the GP4000s (am leaning towards them) in 25 are actually 24mm wide......... maybe this is the way to go? Sooooo many choices.


Have no concerns for the tire width. Any rim that you can run a 23 with, you can also run a 25. While outside of the ETRTO spec, people have been running 32-35c cyclocross tires on rims that wide for years with few issues.

Side note: I have never seen an equipment discussion where one product (GP4000) was so overwhelmingly popular. I've been using Bontrager tires, maybe I need to try these..


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## Fai Mao

davidka said:


> Have no concerns for the tire width. Any rim that you can run a 23 with, you can also run a 25. While outside of the ETRTO spec, people have been running 32-35c cyclocross tires on rims that wide for years with few issues.
> 
> Side note: I have never seen an equipment discussion where one product (GP4000) was so overwhelmingly popular. I've been using Bontrager tires, maybe I need to try these..


Exactly.
If you look for example at the "New Vento Reaction CX wheels. They use the same rim as the regular Vento Reaction wheels but Campagnolo says they can be used with tires up to 35 mm wide for cyclocross.

I think it becomes a problem when you go ballon tires, 40+ mm wide. Also if you measure the ACTUAL width of some tires you find that the listed width is more of a suggestion than a fact.


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## bombertodd

I switched to 25c tires a while back. I like the 25c feel a lot better. It smooths out the harsh ride I felt with the 23c tires. I'm a clyde so the 25c make sense for me. I've ran the following tires so far:

Best: Vittoria Evo Corsa CX - Great feel and tons of grip (no flats after 1,500 miles)

Close second: Veloflex master 25 - Great feel and tons of grip (1 flat after 1,100 miles and still in use)

Third: Conti GP4000s - Harsh feel compared to other high end tires and average grip (5 flats after 1,500 miles)

All three felt the same in terms of rolling resistance to me. 

I have a pair of Schwalbe Ultremo tires ready to be mounted up. I hope these perform as well as the Veloflex or Vittorias.


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## Mace2180

I have changed from bontrager 25to gator skins 25 huge difference. Close to the 4000's. the seem to take vibration a lot better and at higher tire pressure.


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## flatsix911

I switched from 23 to 25 Michelen Pros. 
Diggin' the ride quality, however the tires are very wide and almost touch the chainstays. Any suggestions for a more narrow 25mm tire? :thumbsup:


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