# Any reason not to go with 28mm tires over 25mm?



## Peter2290

So I picked up a 2016 Evo Hi-MOD (Ksyrium Elite wheelset) this winter, and I'm looking to get a pair of Vittoria Corsa G+ tires to replace my aging 25mm GP4000S II.

There seems to be plenty of clearance with my 25mm Conti's (which measure ~27.5mm on the Ksyriums) at the fork/seatstays/chainstays/brakes, and Cannondale says the frame fits 28mm tires.

Would there be any reason (besides a small weight penalty) to get the 25mm tires vs. 28mm? Seems like 28s would be faster at the same pressure I run now or just as fast and more comfortable if I run them at a slightly lower pressure.

Thanks!


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## harryman

If they fit, there is no reason at all IMO. I'm not sure what the Vittorias actually measure compared to the stated dimensions. Most of the 28's I've run stretch out to between 29-30 eventually, gaining an mm or two from where they were when new, so if you have the clearance, go for it. The only 28's I've run that were undersized were conti 4seasons, and just barely.


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## trekninja

i guess its all personal preference. i have bikes with 25s, 28s, and 32s. i dont feel a massive difference in comfort but i do like the feel of a high psi 25c best. it feels fast and agile to me.


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## Jay Strongbow

Bike handling will be a little slower. Whether you call that 'less twitchy' and like it or 'sluggish' and don't, I can't say.


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## Enoch562

THe 28 Vittoria Corsa G is a bit smaller than the Conti 4000s 28. THey are nice tires. I'm guessing they will be around 30ish on your rims


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## velodog

Jay Strongbow said:


> Bike handling will be a little slower. Whether you call that 'less twitchy' and like it or 'sluggish' and don't I can't say.


Have you compared the different tires on the same bike and wheels? And is it something that you could feel, or were you able to measure the differences with a power meter, clock and multiple runs?


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## DrSmile

velodog said:


> Have you compared the different tires on the same bike and wheels? And is it something that you could feel, or were you able to measure the differences with a power meter, clock and multiple runs?


Not commenting on the premise, but having run 23, 25, and 28mm Rubino Pros on the same bike and wheels, I settled on 25s. It feels more like a race tire and it's comfortable. In full disclosure it is on a single speed road bike that I ride during shoulder season (ie gravel, sand, dirt, and garbage on the roads).


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## cxwrench

I'm all about wider tires but those Mavic rims are pretty narrow so you really won't be able to take full advantage of the wider tires. Get some nice wide rim wheels while you're at it.


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## Srode

A little slower and heavier


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## velodog

Srode said:


> A little slower and heavier


How much slower?


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## Lombard

I went from 25s to 28s and I'll never go back. Much nicer ride since you can run lower pressure and no noticeable difference in speed - they did not feel slower or heavier to me. IMO, as long as they will fit in your frame, it's a no-brainer.


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## Srode

velodog said:


> How much slower?


Depends..... 

Check out some the rolling resistance tests to see the watt difference


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## velodog

Srode said:


> Depends.....
> 
> Check out some the rolling resistance tests to see the watt difference


This test sez the bigger the tire the lower the rolling resistance, so how does that make you slower?

Continental Grand Prix 4000S II 23 25 28 mm Comparison


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## Lombard

Oh Gawd, not another narrow/wide tire debate. :Yawn:

Sure, look at the difference in watts. Can anybody tell me with a straight face that they can feel the difference of 5 watts?


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## velodog

Lombard said:


> Oh Gawd, not another narrow/wide tire debate. :Yawn:
> 
> Sure, look at the difference in watts. Can anybody tell me with a straight face that they can feel the difference of 5 watts?


I can positively say that I can not feel it.

On another note, someone in one of these replies said that the handling will change, said the larger tires will be less twitchy or sluggish, whatever you'd want to call it. Now I can't compare apples to apples because they are 2 different bikes with different wheel sizes, but I can say that there is nothing sluggish about the handling of the bike with the 650b\42mm wheel tire combo.

And on the 700c bike, when I went from 23mm to 25mm, same tire, the handling didn't get sluggish. If anything a larger tire having a larger foot print should have the handling improve, allowing faster cornering and more lean angle before losing traction.


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## bvber

cxwrench said:


> I'm all about wider tires


There's got to be a point where it's no longer a benefit beyond... :confused5:


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## Lombard

bvber said:


> There's got to be a point where it's no longer a benefit beyond... :confused5:


I'd say it's no longer a benefit here.....in rolling resistance that is.


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## cxwrench

Jay Strongbow said:


> Bike handling will be a little slower. Whether you call that 'less twitchy' and like it or 'sluggish' and don't I can't say.


The way the bike handles can't change. That's all based on the geometry of the bike, which won't change if you change both tires. The weight of the wider tire is slightly higher, which will very very very very very slightly increase the amount of weight you're actually 'steering'. I don't think most people would be able to feel it. Some might, and that might lead to a feeling of slightly more stability w/ a heavier tire(greater moment of inertia), but it won't change the way the bike actually steers. Not possible.


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## harryman

cxwrench said:


> The way the bike handles can't change. That's all based on the geometry of the bike, which won't change if you change both tires. The weight of the wider tire is slightly higher, which will very very very very very slightly increase the amount of weight you're actually 'steering'. I don't think most people would be able to feel it. Some might, and that might lead to a feeling of slightly more stability w/ a heavier tire(greater moment of inertia), but it won't change the way the bike actually steers. Not possible.


Actually, trail does change when you change tire sizes/overall wheel diameter which affects handling, although the difference between a 25mm and a 28 is negligible, so I'd say it's a wash. I never noticed a difference between 25/28. I did convert a 26" mtb to 700c x 42mm tires and that was beyond negligible. It took a while to get it dialed. 

You can test it here: Bicycle Trail Calculator | yojimg.net


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## Lombard

cxwrench said:


> The way the bike handles can't change. That's all based on the geometry of the bike, which won't change if you change both tires. The weight of the wider tire is slightly higher, which will very very very very very slightly increase the amount of weight you're actually 'steering'. I don't think most people would be able to feel it. Some might, and that might lead to a feeling of slightly more stability w/ a heavier tire(greater moment of inertia), but it won't change the way the bike actually steers. Not possible.


Interesting. So the feeling of better stability when I went to wider tires was due to more front weight and not because of a greater contact patch?

I could have sworn my bike felt more stable and better going around corners when I went from 15mm rims to 17mm rims - effectively widening my tires with no added weight. Placebo effect?


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## cobra_kai

Tire size will also affect bottom bracket height which will change handling. But as harryman said the difference between 25 and 28 mm is very small as far as those changes go.


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## cxwrench

Lombard said:


> Interesting. So the feeling of better stability when I went to wider tires was due to more front weight and not because of a greater contact patch?
> 
> I could have sworn my bike felt more stable and better going around corners when I went from 15mm rims to 17mm rims - effectively widening my tires with no added weight. Placebo effect?


No, that may make a change that is noticeable...changing the shape of the contact patch might make it feel a bit different.


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## Lombard

cxwrench said:


> No, that may make a change that is noticeable...changing the shape of the contact patch might make it feel a bit different.


Ahh, OK, thanks CX. Interestingly, when I went from a 14mm to a 15mm rim, I could feel it. When I went from a 15mm to 17mm rim, I could feel it.

But.....when I went from 17mm to 18mm, no difference in feel.

I'm guessing the law of diminishing returns applies here.


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## Kerry Irons

cxwrench said:


> The way the bike handles can't change. That's all based on the geometry of the bike, which won't change if you change both tires. The weight of the wider tire is slightly higher, which will very very very very very slightly increase the amount of weight you're actually 'steering'. I don't think most people would be able to feel it. Some might, and that might lead to a feeling of slightly more stability w/ a heavier tire(greater moment of inertia), but it won't change the way the bike actually steers. Not possible.


There is this thing called pneumatic trail. Jan Heine of Bicycle Quarterly has discussed it at length. Changing tire sizes changes pneumatic trail.


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## Jay Strongbow

velodog said:


> Have you compared the different tires on the same bike and wheels? And is it something that you could feel, or were you able to measure the differences with a power meter, clock and multiple runs?


Yes
Yes
No

How to heck do you figure someone could measure handling with a powermeter or clock?


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## wim

velodog said:


> the bigger the tire the lower the rolling resistance


Unless you put in the missing piece "at identical pressures," this is pretty much bunk when made as a general statement.


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## velodog

wim said:


> Unless you put in the missing piece "at identical pressures," this is pretty much bunk when made as a general statement.


Yep, I know, and that was stated in the link. I didn't paste and copy the whole link because I figured that if anyone was interested all they had to do was open the link. 

From the link.
The bigger the tire, the lower the rolling resistance at the same air pressure. When you run lower air pressures, the differences get even bigger.


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## velodog

Jay Strongbow said:


> Yes
> Yes
> No
> 
> How to heck do you figure someone could measure handling with a powermeter or clock?


Faster handling equals quicker times over the same course under the same power.


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## Jay Strongbow

velodog said:


> Faster handling equals quicker times over the same course under the same power.


um, no, it doesn't.


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## velodog

Jay Strongbow said:


> um, no, it doesn't.


Then why strive for faster handling?

If the bike handles faster it'll get you through the corner faster, so how doesn't that translate to quicker times over the same course? How many times do you go through corners in a crit, and if your bike is faster handling than your competitors you make time in every corner and if your power output, handling skills and tactical savy are equal to theirs, you win.


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## Jay Strongbow

velodog said:


> Then why strive for faster handling?
> 
> If the bike handles faster it'll get you through the corner faster, so how doesn't that translate to quicker times over the same course? How many times do you go through corners in a crit, and if your bike is faster handling than your competitors you make time in every corner and if your power output, handling skills and tactical savy are equal to theirs, you win.


First off not every ride or race is a crit with sharp corners but going fast though corners and having a fast handling bike are not the same things. I have no interest in arguing about it though.


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## velodog

Jay Strongbow said:


> First off not every ride or race is a crit with sharp corners but going fast though corners and having a fast handling bike are not the same things. I have no interest in arguing about it though.


I didn't realize that we were arguing.


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## Jon blaze

I like to keep things simple (yes it is possible.) most of these “discussions” are fueled by someone wanting to be someone else and that is always a recipe for confusion. I will only speak for me and NOT the Tour de France champion, the peloton pro, the weight Wiener (weenie) or the Doc Brown of Wattage. I’ve ridden and currently ride 23,25,28,32,33 and 35c+ tires. All relatively, No, Very smooth tread(accept for the 35). I started again as an adult in my 30s on the 700/35c, since my passion for cycling is different probably from most in this forum I started frequently riding as an adult on a hybrid trek 720 multitrack because I loved riding bikes as a kid with friends around the neighborhood and beyond. Never intended nor desired to be a pro rodie.(maybe if I looked better in spandex) But I realized that I could ride as an adult with friends long after the days of Huffy, Haro, mongoose, diamondback, redline & GT! Though I’m not a pro, I do have a competitive instinct and I push myself to what limits “I’m” capable of and have tracked progress with crude and obsolete methods like Garmin and Map My Ride... And by doing so this long monologue/biography/confession comes to a sharp conclusive yet simple point. All of my stats showed I was fastest ALL of the time on 700/23c, but NOT by much for MY requirements. 2-4mph faster on average than my 32&33c’s and NOT nearly as comfortable. If you think about it TT bikes are much faster than road bikes though that gap is closing as today’s tech continues to advance but you’d be hard pressed to find a TT bike that’s using anything over 25c in competition. And I believe that to be due to the CONDITIONS the individual is riding on. GCN did a great (as usual) video on mountain bike vs Gravel bike and what it came down to in the end was terrain. So if you’re on fresh paved tarmac or a classic hardwood Oval then I would guarantee a thinner tire would give you a win all other physics/mechanics being equal. Again, are you riding for time? Or purely for recreation? Because if it’s for rec, then the comfort provided by a wider tire may make that experience more pleasant. And if it’s seconds/mph you’re after then minimize the wheel size. While you’re at it change the head angle, ride geometry, ride position and maximize your aerodynamics(start with spandex). But I’m gonna give ALL you bike nerds and gear geeks a sip from the holy grail of cycling knowledge with my last and final suggestion. Prepare to have your minds BLOWN! Here it is, Are you READY?!?!....
Focus less on watts, and More on SQUATS. Oh yeah, and don’t forget tread. Tread DEFINITELY affects roll resistance, which affects speed, which affects handling... BTW my most comfortable tires are my soma shikkoro 33s and my fastest are my Vitoria corsa 23s.


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## No Time Toulouse

Jon blaze said:


> I like to keep things simple (yes it is possible.) most of these “discussions” are fueled by someone wanting to be someone else and that is always a recipe for confusion. I will only speak for me and NOT the Tour de France champion, the peloton pro, the weight Wiener (weenie) or the Doc Brown of Wattage. I’ve ridden and currently ride 23,25,28,32,33 and 35c+ tires. All relatively, No, Very smooth tread(accept for the 35). I started again as an adult in my 30s on the 700/35c, since my passion for cycling is different probably from most in this forum I started frequently riding as an adult on a hybrid trek 720 multitrack because I loved riding bikes as a kid with friends around the neighborhood and beyond. Never intended nor desired to be a pro rodie.(maybe if I looked better in spandex) But I realized that I could ride as an adult with friends long after the days of Huffy, Haro, mongoose, diamondback, redline & GT! Though I’m not a pro, I do have a competitive instinct and I push myself to what limits “I’m” capable of and have tracked progress with crude and obsolete methods like Garmin and Map My Ride... And by doing so this long monologue/biography/confession comes to a sharp conclusive yet simple point. All of my stats showed I was fastest ALL of the time on 700/23c, but NOT by much for MY requirements. 2-4mph faster on average than my 32&33c’s and NOT nearly as comfortable. If you think about it TT bikes are much faster than road bikes though that gap is closing as today’s tech continues to advance but you’d be hard pressed to find a TT bike that’s using anything over 25c in competition. And I believe that to be due to the CONDITIONS the individual is riding on. GCN did a great (as usual) video on mountain bike vs Gravel bike and what it came down to in the end was terrain. So if you’re on fresh paved tarmac or a classic hardwood Oval then I would guarantee a thinner tire would give you a win all other physics/mechanics being equal. Again, are you riding for time? Or purely for recreation? Because if it’s for rec, then the comfort provided by a wider tire may make that experience more pleasant. And if it’s seconds/mph you’re after then minimize the wheel size. While you’re at it change the head angle, ride geometry, ride position and maximize your aerodynamics(start with spandex). But I’m gonna give ALL you bike nerds and gear geeks a sip from the holy grail of cycling knowledge with my last and final suggestion. Prepare to have your minds BLOWN! Here it is, Are you READY?!?!....
> Focus less on watts, and More on SQUATS. Oh yeah, and don’t forget tread. Tread DEFINITELY affects roll resistance, which affects speed, which affects handling... BTW my most comfortable tires are my soma shikkoro 33s and my fastest are my Vitoria corsa 23s.


tl;dr.....
Thank you for that stream-of-consciousness diatribe. The 5 minutes it took for me to read it could've been better spent on the crapper. We look forward to further screeds from you in the future....


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## Lombard

No Time Toulouse said:


> tl;dr.....
> Thank you for that stream-of-consciousness diatribe. The 5 minutes it took for me to read it could've been better spent on the crapper. We look forward to further screeds from you in the future....


Well you could have waited till you were on the crapper and read it there on your phone.


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## Kerry Irons

Jon blaze said:


> I like to keep things simple (yes it is possible.) most of these “discussions” are fueled by someone wanting to be someone else and that is always a recipe for confusion. I will only speak for me and NOT the Tour de France champion, the peloton pro, the weight Wiener (weenie) or the Doc Brown of Wattage. I’ve ridden and currently ride 23,25,28,32,33 and 35c+ tires. All relatively, No, Very smooth tread(accept for the 35). I started again as an adult in my 30s on the 700/35c, since my passion for cycling is different probably from most in this forum I started frequently riding as an adult on a hybrid trek 720 multitrack because I loved riding bikes as a kid with friends around the neighborhood and beyond. Never intended nor desired to be a pro rodie.(maybe if I looked better in spandex) But I realized that I could ride as an adult with friends long after the days of Huffy, Haro, mongoose, diamondback, redline & GT! Though I’m not a pro, I do have a competitive instinct and I push myself to what limits “I’m” capable of and have tracked progress with crude and obsolete methods like Garmin and Map My Ride... And by doing so this long monologue/biography/confession comes to a sharp conclusive yet simple point. All of my stats showed I was fastest ALL of the time on 700/23c, but NOT by much for MY requirements. 2-4mph faster on average than my 32&33c’s and NOT nearly as comfortable. If you think about it TT bikes are much faster than road bikes though that gap is closing as today’s tech continues to advance but you’d be hard pressed to find a TT bike that’s using anything over 25c in competition. And I believe that to be due to the CONDITIONS the individual is riding on. GCN did a great (as usual) video on mountain bike vs Gravel bike and what it came down to in the end was terrain. So if you’re on fresh paved tarmac or a classic hardwood Oval then I would guarantee a thinner tire would give you a win all other physics/mechanics being equal. Again, are you riding for time? Or purely for recreation? Because if it’s for rec, then the comfort provided by a wider tire may make that experience more pleasant. And if it’s seconds/mph you’re after then minimize the wheel size. While you’re at it change the head angle, ride geometry, ride position and maximize your aerodynamics(start with spandex). But I’m gonna give ALL you bike nerds and gear geeks a sip from the holy grail of cycling knowledge with my last and final suggestion. Prepare to have your minds BLOWN! Here it is, Are you READY?!?!....
> Focus less on watts, and More on SQUATS. Oh yeah, and don’t forget tread. Tread DEFINITELY affects roll resistance, which affects speed, which affects handling... BTW my most comfortable tires are my soma shikkoro 33s and my fastest are my Vitoria corsa 23s.


Say what?


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## Jon blaze

No Time Toulouse said:


> tl;dr.....
> Thank you for that stream-of-consciousness diatribe. The 5 minutes it took for me to read it could've been better spent on the crapper. We look forward to further screeds from you in the future....


Anytime.


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## Jon blaze




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## DrSmile

No Time Toulouse said:


> tl;dr.....
> The 5 minutes it took for me to read it could've been better spent on the crapper.


But is it faster to crap wider or narrower poops? Maybe you could crap in 4.5 instead of 5 minutes, think of all the stuff you could get done!


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## Lombard

DrSmile said:


> But is it faster to crap wider or narrower poops? Maybe you could crap in 4.5 instead of 5 minutes, think of all the stuff you could get done!


Do wider poops have less rolling resistance?


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## tlg

Lombard said:


> Do wider poops have less rolling resistance?


If you polish them, they have less resistance.

And yes.... yes you can polish a turd.


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## Lombard

tlg said:


> If you polish them, they have less resistance.
> 
> And yes.... yes you can polish a turd.


Ahhh, so that's how they get that moose poop jewelry nice and shiny!



moose poop jewelry maine - Google Shopping



I have to wonder if they really don't know how to spell turd or if they're just trying to bypass web filters:



https://moosetirds.com/


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