# 23 vs 25mm tires



## Vitamin G

Question concerning people's experience with 23 vs 25mm tires.

The reason I am asking is I am trying to understand what has more impact on the way a frame feels "buzzy" or harsh on rough pavement. I normally ride a Trek 2100 Aluminum with carbon stays. I recently test rode a new Trek 2.3 which is all aluminum. It felt more harsh than my bike, but the 2.3 had 23mm tires, and my bike has 25mm tires. Both bikes had the tires set to the same pressure (100 psi).

So, is the difference probably attributable to the tires? or is it really the frame material?


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## Retro Grouch

I recent switched from 23mm to 25mm Continental Gatorskins on my steel road bike and kept the same 110 psi. There is a slight difference in ride quality and less frame buzz. Then again, it could be more from going from old worn tires to a fresh set.


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## Blackss06

I typically ride both everyday. I really can't tell a significant difference in ride quality, I try to stay on nicely paved roads but it hardly happens.


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## crossracer

I ride both 23 and 25, and there is a difference. THe same way you can feel the difference between a cheap tire and a really nice one, you can feel a difference between a 23 and a 25. 
AS of late most of my rides have been on a set of 32 spoke wheels and 25 mm tires. But that also brings up the question, were the wheels different? That would also account for a lot of road feel also.

Bill


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## Vitamin G

Yes, the wheels were different - sort of. My bike has Bontrager Select wheels, the 2.3 has newer Bontrager Race wheels. Probably not that much different after all, except my old Select wheels have a low spoke count pattern.


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## Sisophous

I had a big interest in this same subject. 

I went from 23 to 25 and the ride is slightly smoother and noticeably faster. There is less rolling resistance with the 25s than with the 23s which makes for a faster ride. I got my Trek new in June of last year and riding for 8 months with the 23 tires I got 4 flats. Riding for two months with the Continental Grand Prix 25s and no flats. I note the tube is the same but the slightly larger tire is less prone to flats.

If I ride over tough terrain on the 25s, it is no better than a 23, I feel it. But overall, the 25s are much better than the 23s. I also have hit some big pot holes with the 25s that would have caused a pinch flat if I had hit them with the 23s.

I fill my tires to the max, 120psi and I do so to maximize my speed. Riding at 100psi will cause more resistance and slow you down.

My last bike I rode for years was an all steel frame Ironman Centurion. That bike had 28 tires and the ride was smoother and my times were just as fast as on my all Carbon Trek bike.


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## Paradox_Q

The biggest difference I noticed when I switched to 25s was that I had less flats and now that is a good thing.


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## JCavilia

Sisophous said:


> I fill my tires to the max, 120psi and I do so to maximize my speed. Riding at 100psi will cause more resistance and slow you down.


wrong


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## GetReal

I ride 23 and 25
s. I feel lno difference.

BTW, if you measure a Conti GP4000 in a 23 against some other brands in a 25 (Sefas Seca), you'll find they are nearly the same. Plus the 23 Seca will be more narrow than the 23 GP.


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## 55x11

JCavilia said:


> wrong


could be right. If the recommended pressure is 120psi, 100 psi is likely to increase the rolling resistance due to increased tire deformation - at least for rolling on smooth surfaces.


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## Richard

Then of course there is the reality that all 700x23's are not created equal.

The 700x23 Bontrager R3+ I have on one bike definitely has more "volume" and is larger in diameter than the Michelin 700x23 Krylion Carbons that I have on a couple of other bikes. And both of those dwarf the 700x23 Panaracer Closers on my fixed.

For that matter, the Continental 700x28's I had on my commuter weren't appreciably bigger in either width or diameter than the Bontragers, and the Panaracer Pasela Tourguards in a 700x28 I replaced the Continentals with are huge in comparison. Go figure.


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## Mersault

http://forums.roadbikereview.com/showthread.php?t=249411

same subject over there.


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## JCavilia

55x11 said:


> could be right. If the recommended pressure is 120psi, 100 psi is likely to increase the rolling resistance due to increased tire deformation - at least for rolling on smooth surfaces.


very smooth surfaces. not the real world, and not the riding conditions he described. On real roads, excessively high pressure means worse control, worse cornering, net slower speeds. Very low pressure will increase rolling resistance enough to cancel those advantages. But not 100 psi.

There is no "recommended pressure" marked on road bike tires, only a "maximum pressure." Almost nobody is well served riding at those pressures.

His misconception is a common one, but it's a misconception nonetheless.


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## Sisophous

JCavilia said:


> very smooth surfaces. not the real world, and not the riding conditions he described. On real roads, excessively high pressure means worse control, worse cornering, net slower speeds. Very low pressure will increase rolling resistance enough to cancel those advantages. But not 100 psi.
> 
> There is no "recommended pressure" marked on road bike tires, only a "maximum pressure." Almost nobody is well served riding at those pressures.
> 
> His misconception is a common one, but it's a misconception nonetheless.


Mr. Cavilia, I thank you for your pompous, arrogant, factually wrong, Mr. Know it All reply. I take it you are an expert qualified to shoot down anyone's point? I try hard not to flame anyone but you can't help but insult others.

My tire pressure is not "EXCESSIVELY HIGH". At 120 psi it is the listed, recommended max pressure, not exceeding it.

I ride, I do not post behind a computer lecturing others about something you clearly know nothing about despite your multitude of posts which makes you think you know something others don't. My rides are clearly faster when I ride with max pressure on my tires. I, nor anyone else need your input to tell us we are wrong. 

Anyone can fill their tires to 100 psi, ride and time themselves, and then fill their tires on another day to 120psi and time themselves and compare the times.

You are one of a number of posters who post wrong information.

Please put a lid on it.


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## Jay Strongbow

I don't notice any difference in "road buzz" if I use the same pressure. 

I do noticed a slight improvement with 25s over rough road (holes, bad cracks ect) but what most people term 'buzz'....no difference felt by me.

Regarding your specific reason for asking op.........frame has such a low impact on road buzz relative to wheels and tires that I'd have to guess that if the difference was so great that it stood out to you in a test drive it indeed had something to do with tires/wheels and not the frame. 

Even when comparing my high end carbon frame to my other aluminum frame with identical wheels and tires I only noticed a difference when I'm many miles into a ride and feel less beat up. I don't actually feel anything different just riding alone. It's the cumulative effect of vibration I don't noticed that I eventually notice.

100% guessing on my part but I got to think the difference you feel is not from the frame if it stood out like that in a test ride. Or if the difference is frame it probably only accounts for a portion of the difference.


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## wim

Jay Strongbow said:


> I don't notice any difference in "road buzz" if I use the same pressure..


At the same pressure, the larger tire is a bit "harder" and deforms a little less than the smaller one. So if anything, you actually should have felt a little _more_ buzz with the larger tire. But the whole idea of going to a larger tire is to be able to ride at less pressures. So getting larger tires and filling them to the same pressure than your smaller ones sort of defeats the reason for the change.


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## Dajianshan

The biggest difference is that 25c is harder to find. As far as speed goes... I had a CO2 malfunction and rode 30 miles at 40psi... at 20mph. I just had to be careful over bumps or potholes.


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## cyclesport45

The difference is 2 millimeters, give or take. . . .


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## Peter P.

Are you sure you used the same air pressure in the tires of both bikes?

Tire pressure is a significant factor in how much a tire can absorb high frequency road irregularities such as chip sealed roads. A larger tire such as a 25 vs. a 23mm will let you run lower pressure so a 25mm tire SHOULD give you a smoother ride. I personally think people inflate their tires too high.

Once air pressure is out of the equation, wheels can be a big factor in transmitting road buzz. Tall rims have a lot of vertical stiffness so won't absorb much.

I think the only factor that's equal to tire pressure in affecting the smoothness of the ride is frame design. Carbon has a tremendous ability to damp road vibration. Carbon forks have a great influence on this as well. Add the carbon stays on your Trek and you have additional damping qualities.

So I think frame material is the number one factor, but tire pressure is almost equal at #2. Tire size may dictate how much pressure you need to prevent pinch flats, but I feel most people over inflate their tires and lose any vibration damping.


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## captain stubbing

Sisophous said:


> Mr. Cavilia, I thank you for your pompous, arrogant, factually wrong, Mr. Know it All reply. I take it you are an expert qualified to shoot down anyone's point? I try hard not to flame anyone but you can't help but insult others.
> 
> My tire pressure is not "EXCESSIVELY HIGH". At 120 psi it is the listed, recommended max pressure, not exceeding it.
> 
> I ride, I do not post behind a computer lecturing others about something you clearly know nothing about despite your multitude of posts which makes you think you know something others don't. My rides are clearly faster when I ride with max pressure on my tires. I, nor anyone else need your input to tell us we are wrong.
> 
> Anyone can fill their tires to 100 psi, ride and time themselves, and then fill their tires on another day to 120psi and time themselves and compare the times.
> 
> You are one of a number of posters who post wrong information.
> 
> Please put a lid on it.


thats the maximum pressure for safety reasons....it is not the recommended pressure!!

your fastest pressure will depend on a couple of things....your weight and the types of roads u ride. it is a fallacy that higher psi = a faster ride.

in a velodrome on a super smooth surface....yes it will be faster, however, on the road with lots of little cracks and bumps etc, a harder tyre (sorry tire) will bounce other the million little bumps and lose energy/speed. thats the reason off road vehicles run lower pressures....so the vehicle glides over the bumps inside of bouncing the car to bits.

essentially the best pressure should be as low enough that u don't get pinch flats, so the max psi of 120 psi is essentially for the heavy weights.

i weight 72 kgs (about 160 pounds i think), and run 90 - 100 psi. if i run 120psi, my hands and arse hurt from the vibration and i'm shattered by the end of a 100km ride.....and its slower (although it may not feel like it). 90 -1 00 psi is a smoother more comfortable ride (for my weight)....and definitely FASTER!!

unless your an elephant, u are overinflating your tire:


•An overinflated tyre will have slightly less rolling resistance if the surface is very smooth..
•An overinflated tyre is more prone to damage from sharp rocks and similar road hazards.
•An overinflated tyre will give a harsh ride on anything but the smoothest pavement.
•An overinflated tyre can bounce on surface roughnesses. This can cause dangerous interruptions in traction, particularly if it happens during cornering.


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## Dajianshan

I remember seeing a tire pressure guide on the Continental site a while back that was based on weight. My optimal pressure for 4000GP was something like 100psi in dry conditions. I can't seem to find the guide now.


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## bigdaddy96

captain stubbing said:


> thats the maximum pressure for safety reasons....it is not the recommended pressure!!
> 
> your fastest pressure will depend on a couple of things....your weight and the types of roads u ride. it is a fallacy that higher psi = a faster ride.
> 
> in a velodrome on a super smooth surface....yes it will be faster, however, on the road with lots of little cracks and bumps etc, a harder tyre (sorry tire) will bounce other the million little bumps and lose energy/speed. thats the reason off road vehicles run lower pressures....so the vehicle glides over the bumps inside of bouncing the car to bits.
> 
> essentially the best pressure should be as low enough that u don't get pinch flats, so the max psi of 120 psi is essentially for the heavy weights.
> 
> i weight 72 kgs (about 160 pounds i think), and run 90 - 100 psi. if i run 120psi, my hands and arse hurt from the vibration and i'm shattered by the end of a 100km ride.....and its slower (although it may not feel like it). 90 -1 00 psi is a smoother more comfortable ride (for my weight)....and definitely FASTER!!
> 
> unless your an elephant, u are overinflating your tire:
> 
> 
> •An overinflated tyre will have slightly less rolling resistance if the surface is very smooth..
> •An overinflated tyre is more prone to damage from sharp rocks and similar road hazards.
> •An overinflated tyre will give a harsh ride on anything but the smoothest pavement.
> •An overinflated tyre can bounce on surface roughnesses. This can cause dangerous interruptions in traction, particularly if it happens during cornering.


This is correct. There have been numerous discussions on this topic on this board with links to supporting studies. 

Running max pressure for best speed is just plain wrong.


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## Mr. Scary

Sisophous said:


> Mr. Cavilia, I thank you for your pompous, arrogant, factually wrong, Mr. Know it All reply. I take it you are an expert qualified to shoot down anyone's point? I try hard not to flame anyone but you can't help but insult others.
> 
> My tire pressure is not "EXCESSIVELY HIGH". At 120 psi it is the listed, recommended max pressure, not exceeding it.
> 
> I ride, I do not post behind a computer lecturing others about something you clearly know nothing about despite your multitude of posts which makes you think you know something others don't. My rides are clearly faster when I ride with max pressure on my tires. I, nor anyone else need your input to tell us we are wrong.
> 
> Anyone can fill their tires to 100 psi, ride and time themselves, and then fill their tires on another day to 120psi and time themselves and compare the times.
> 
> You are one of a number of posters who post wrong information.
> 
> Please put a lid on it.


Have you been riding about three months? Your anecdotal 6 mile ride doesn't mean anything. If I felt like digging it up I'd post the Schwalbe tire studies which pointed to lower pressures and bigger volume as being faster in real world applications. But I'm guessing you are more of an expert than the Schwalbe engineers?


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## mrcookie

i ride 25s because someone convinced me they would provide a more comfortable ride. i weigh 220 and ride them at about 100 psi, and have never had a pinch flat in 6000 miles on the 25s. 1/4 mph faster or slower, i could care less about....


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## Pablo

Not to pick on anyone, but honestly, who gets insulted and offended about an interwebs discussion of tire pressure? Most of these sorts of discussions with people who get (or seem to be) offended are about as useful as pushing a rock up a hill over and over. 

Some resources can't hurt: 

http://www.cyclingnews.com/features/tech-feature-the-work-of-wheel-energy 

http://www.sheldonbrown.com/tires.html


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## danl1

Pablo said:


> Some resources can't hurt:


Additionally:

http://www.bikequarterly.com/images/TireDrop.pdf

And while it's on a tandem site:
http://www.tandem-bicycle-central.com/bicycle-tires.html

There is this thing from a guy that might know something about it...


Tire Pressure Calculation

A quote that comes to mind is something Andy Hampsten told me once when we were going to leave on a ride in Tuscany. He said, "Most people put too much pressure in their tires. They think they need a rock hard tire but they really need is the right pressure. Most riders on road bikes need only about 90psi in their front tire but you see guys pumping them up to 120 all the time". He also said that many people pump up their tires every day but don't bother to really check the pressure. "Unless you are riding tubulars, you don't need to pump your tires every day"

The correct tire pressure can make or break a tire, literally. If you want to be very scientific about it click here for a chart about bicycle tire pressure from Precision Tandems.


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## rward325

Here this one is from HED in regards to the wider C2(23mm) rim comapred to normal(19mm) wheels just to add fuel to the fire.

Q. Dear Mr. Hedtech, how much PSI should I run in my C2 rims?

A. Our wider C2 rims should be run at AT LEAST 11% lower pressure than you would use in the same tires on a 19mm rim. I weigh 165 lbs and run 22mm tires at 80-90 psi. Because the C2 rim is wider, your tire's air volume is greater than it would be on a 19mm rim and PSI needs to decrease.

Excessive pressure will do two things:
- Compress the rim slightly and decrease spoke tension
- Harden the tire to such a degree that it no longer has the small amount of flex that it would have at a lower pressure or on a narrower rim. The flex is both lateral and vertical. In the case of the wheel rubbing the brakes or frame, lateral flex is what we are concerned with. As frames and wheels have gotten stiffer and stiffer over the past decade, torsional force on a bike has gotten more noticeable.


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## High Gear

I like running 25's in the back and 23's up front. Just yesterday I put a 23 on the rear (it's all I had) because the tire was worn too thin. I noticed a slightly harsher ride. I think 25's are great for training on the roads we have to live with. I think people are stuck on 23's because they close to the same diameter as the tubulars pros race on. For every day riding, 25's make more sense. I remember when 18's became the craze in the '90s. People thought the smaller the tire, the smaller the contact patch, therefore less rolling resistance. Not true. Read this:

http://www.bicycletires.com/a_49/tire_width/article.htm


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## wim

*People were right.*



High Gear said:


> People thought the smaller the tire, the smaller the contact patch, therefore less rolling resistance.


Actually, it is true at recommended pressures. The "larger tire = smaller contact patch" mantra is only true at identical pressures as pointed out by the article at the link you posted.


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## axlenut

Hi all, TireDrop.pfd is a real good read! I have used the info to set the pressure on all my bikes.

Some interesting observations: my steel SS road bike has 23mm tires on it and I set the pressure to 80 front and 100 rear. The ride is good but not near as good as my carbon fork/ aluminium frame CX bike on rough pavement or brick roads.

The CX bike has Ritchey Speed Max 32mm tires and I can run half the pressure in them - 40 front and 50 rear.

The bigger the tire the less air you can and should run in them. The front also has less weight on it so you can and should run less air.

Getting back to the OP question I have no doubt 25 mm tires will give a better ride then 23 mm tires provided you run less pressure in them. Just use the TireDrop.pdf and your weight to set the correct pressure for both the front and rear.

Later, Axlenut


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## Vitamin G

Thanks everybody, but I am still working on my original problem, which to decide if I want to take the crash replacement 2.3 frame in exchange for my 2100 frame. That's why I was riding the two bikes back to back in the first place.


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## cxwrench

Sisophous said:


> Mr. Cavilia, I thank you for your pompous, arrogant, factually wrong, Mr. Know it All reply. I take it you are an expert qualified to shoot down anyone's point? I try hard not to flame anyone but you can't help but insult others.
> 
> My tire pressure is not "EXCESSIVELY HIGH". At 120 psi it is the listed, recommended max pressure, not exceeding it.
> 
> I ride, I do not post behind a computer lecturing others about something you clearly know nothing about despite your multitude of posts which makes you think you know something others don't. My rides are clearly faster when I ride with max pressure on my tires. I, nor anyone else need your input to tell us we are wrong.
> 
> Anyone can fill their tires to 100 psi, ride and time themselves, and then fill their tires on another day to 120psi and time themselves and compare the times.
> 
> You are one of a number of posters who post wrong information.
> 
> Please put a lid on it.


wow, you are truly confused.


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## dgeesaman

I find that the extra 2mm makes little difference, but the reduction in tire pressure (15psi) is a noticeable improvement in comfort. I weigh 200lb, ride 23s at 100psi, 25s at 85psi, and have not had a pinch flat in 2200miles since I started riding last year.

Note that it makes no sense to run your 23s and 25s at the same pressure. The load capacity of a tire is directly proportional to inflated volume and tire pressure. Increased volume = decreased pressure and softer ride. This is just like car tire pressure: the optimal pressure is on the door jamb, not the maximum allowed by the tire.

There is not a lot of data out there on rolling resistance w.r.t. pressure because it's so hard to measure accurately. It is fair to say that there is point of diminishing returns, and IMHO that point is well below the tire maximum pressure.


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## MR_GRUMPY

At your weight, 25's are the correct size tire for you. You could put a 23 in front without any more pinch flats because 60% of your total weight is on the back wheel.

If you have two tires, a 23 and a 25, that weigh exactly the same, the 25 will ride smoother, and faster, and will be able to corner quicker than a 23.

The exception to this, is if you are able to ride at 28 mph or faster, or if you ride on a super smooth velodrome. (on the track, go ahead and punp up to 150/160)


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## Pablo

danl1 said:


> A quote that comes to mind is something Andy Hampsten told me once when we were going to leave on a ride in Tuscany.


I am oozing with envy. Plus, when you roll on 32s like Andy supposedly does, even less (pressure) is even better.


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## JCavilia

Sisophous said:


> Mr. Cavilia, I thank you for your . . .reply.


You're welcome. I always endeavor to be helpful and courteous.


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## Oasisbill

http://cptips.com/tires.htm


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## Hank Stamper

Sisophous said:


> Mr. Cavilia, I thank you for your pompous, arrogant, factually wrong, Mr. Know it All reply. I take it you are an expert qualified to shoot down anyone's point? I try hard not to flame anyone but you can't help but insult others.
> 
> My tire pressure is not "EXCESSIVELY HIGH". At 120 psi it is the listed, recommended max pressure, not exceeding it.
> 
> I ride, I do not post behind a computer lecturing others about something you clearly know nothing about despite your multitude of posts which makes you think you know something others don't. My rides are clearly faster when I ride with max pressure on my tires. I, nor anyone else need your input to tell us we are wrong.
> 
> Anyone can fill their tires to 100 psi, ride and time themselves, and then fill their tires on another day to 120psi and time themselves and compare the times.
> 
> *You are one of a number of posters who post wrong information*.
> 
> Please put a lid on it.


Classic. The poster who made a name for himself with his anti-bike fit rants talking a shot at one of the most helpful and accurate on the board. Gotta love the internet.


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## JustTooBig

*if you need some REAL entertainment...*



cxwrench said:


> wow, you are truly confused.


do a quick search of Sis's posting history. 

Despite very, very little cycling-related experience and virtually no knowledge of any related topics (bike maintenance, biomechanics, physiology, frame materials, human (or materials) performance, etc.), Sis is already rather notorious for posting stuff like the above nonsense based on generalizations, "common knowledge", rumor, mistaken notion, legend, folklore, you name it... and then he gets bent out of shape -- in exactly the manner we've seen in this thread -- when someone calls his BS, which unfortunately is based solely on ignorance. 

Yes, the PSI on the tire is MAX, not the recommended pressure. NO, inflating to max PSI does not really decrease rolling resistance (only in nearly perfect, smooth surfaces, which don't really exist IRL). But you should all stop confusing Sis with factual stuff and just let him revel in his "knowledge", misguided as it may be.

Bottom line ...... Sis has no credibility whatsoever on cycling-related topics, but boy can he be entertaining!


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## MorganRaider

I have a 2.3, '11 model to be exact. I switched from stock tires (Bontrager hardcase 23's) to Continental 4000S 25's and found a signficant increase in ride quality. Rolling resistance seemed to be about the same. Both sets of tires run 115-120 psi.


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## Doctor Mabuse

I don't think anyone has linked to the Michelin site yet (in this thread), which is my first stop for ballpark tyre pressure info.

So here's that helpful and reasonably authoritative resource to pitch into the debate:

Michelin Recommended Tyre Pressures

It's not the last word obviously - just a starting point as Michelin say: "The chart below should give you a reasonable guide of where to start when experimenting to find the proper tire pressure for you."


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## Jim311

Why in the hell would you even BUY 25s if you were going to max out the pressure? If you raise the volume, you should be able to LOWER the pressure. Otherwise you are increasing weight and contact patch and therefore reaping none of the benefits of a higher volume tire.


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## Oasisbill

MorganRaider said:


> I have a 2.3, '11 model to be exact. I switched from stock tires (Bontrager hardcase 23's) to Continental 4000S 25's and found a signficant increase in ride quality. Rolling resistance seemed to be about the same. Both sets of tires run 115-120 psi.


I went from Bontragers to Conti GP4K 23s and the ride quality was dramatically better, so I wonder if it's just the tyre quality or the width?


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## Slow Ride

Oasisbill said:


> I went from Bontragers to Conti GP4K 23s and the ride quality was dramatically better, so I wonder if it's just the tyre quality or the width?


I think it's just they are different tires; different design and purpose. The Bontrager Hardcase is a perfectly fine tire, but constructed differently than a GP4000. How I don't know, except that the Hardcase uses thicker material and has a different compound. I can run a Hardcase with less air than a GP4000 without pinch flatting. Both tires perform fine, but feel different. I run the Hardcase for longer rides over rough roads, to beat me up less over the long haul. The wheels with Conti are generally used for very fast rides under 40 miles. No hard rule. Just depends on how I anticipate the ride to go and how much performance I want vs. comfort/durabilty. If I had to give one up it would be the Hardcase. But to run the Contis as soft as the Hardcase I increase the risk of pinch flatting. The Hardcase are a someone less balanced tire, too. A mounted Conti rotates perfectly evenly when spun. Hardcases I've had have more unevenness during rotation.


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## leadout_kv

Hank Stamper said:


> Classic. The poster who made a name for himself with his anti-bike fit rants talking a shot at one of the most helpful and accurate on the board. Gotta love the internet.


You hit the nail right on the head. That guy (Sisophous) has been warned by the admins in the past for his postings.

Hey Sisophous ya just don't learn do ya?


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## the_don

This thread is surprisingly good! I learnt a few things, had a good old chuckle over siphilis's ranting and will try experimenting with slightly lower pressures in my 23's. 

I usually fill to 100psi, but will try 90 next ride. I'm 10kg overweight at 80kg at the moment. Oh the humanity.


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## T0mi

JCavilia said:


> very smooth surfaces. not the real world, and not the riding conditions he described. On real roads, excessively high pressure means worse control, worse cornering, *net slower speeds*. Very low pressure will increase rolling resistance enough to cancel those advantages. But not 100 psi.
> 
> There is no "recommended pressure" marked on road bike tires, only a "maximum pressure." Almost nobody is well served riding at those pressures.
> 
> His misconception is a common one, but it's a misconception nonetheless.


Being arrogant doesn't make you feel right.

On real roads and for a particular rider, there is an ideal all around pressure which is much lower than the maximum one. We agree with that. However, inflating at an higher pressure than the ideal one will not increase rolling resistance. It will just reduce cornering grip and comfort while not reducing rolling resistance (or only marginally on the smoothest surfaces). 

Therefore people who increase their tires at max pressure will not gain nor loose rolling resistance, and it can have other advantages : a tire inflated at max pressure, not higher, will wear slower. If you care more about durability than cornering grip and comfort, this is not a bad idea. Each to their own. 

I have lived in a place were all roads were almost perfect. The roads were so good and new there was no comfort reduction by inflating at max pressure so I used to inflate them higher than I do it now. Grip was not an issue because there was no major downhill. I only reduced tire pressure when I expected rain for safety reasons.

And yes, there are "recommended pressure", and it is sometimes marked in the tires, although it is given as a range because the ideal pressure is not the same for everybody.


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## mattotoole

At 175# I go to 7-8 bar for 23mm, maybe 8 in the rear to allow for a few days' leakdown.

I've had 2 pro mechanics tell me they use ~7 bar for most riders.


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## RJP Diver

Paradox_Q said:


> The biggest difference I noticed when I switched to 25s was that I had less flats and now that is a good thing.


Fewer flats = faster times, for sure.


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## cch

There is a lab in Norway(?) that does a lot of work on tire studies. According to a recent article in Velonews or Cyclingnews (can't find it at the moment), they determined that 25c tires have lower rolling resistance, because the shape of the contact patch is wider rather than taller.

Another benefit of 25c tires is that you can run lower pressure without increasing your risk of pinch flats, which adds to the comfort and grip of the tire.

My experience is that tire pressure is the single largest contributor to ride quality. Then the wheels, then the frame. 

Going from 23c clinchers at 110psi to 25c tubeless at 90psi will completely change the ride quality. Rolling resistance is nearly impossible to feel, and tough to test, but the 25c tires I ride don't feel sluggish.


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## SpecializedMok

just another thing to mention: I recently purchased the HED Belgium C2 rims with Vittoria Open Pave tires (24mm tires). I like em compared to my Syrium Equipes. The ride is smoother and perhaps other people can chime in on this since if they've tried it as well...


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## Beekeeper

+1 for Open Paves. Best tyre I've used. Seemingly the perfect compromise at 24mm.


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## cleon

Doctor Mabuse said:


> I don't think anyone has linked to the Michelin site yet (in this thread), which is my first stop for ballpark tyre pressure info.
> 
> So here's that helpful and reasonably authoritative resource to pitch into the debate:...
> 
> It's not the last word obviously - just a starting point as Michelin say: "The chart below should give you a reasonable guide of where to start when experimenting to find the proper tire pressure for you."
> 
> 
> This is very helpful for me <=newb..so thanks for posting. I realize it might be out there already but I saw it here first so thanks! (my wife is 100lbs and i'm 200 and filling both to 100psi..looks like that's just plain bad...)


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## SSRider

SpecializedMok said:


> just another thing to mention: I recently purchased the HED Belgium C2 rims with Vittoria Open Pave tires (24mm tires). I like em compared to my Syrium Equipes. The ride is smoother and perhaps other people can chime in on this since if they've tried it as well...


i have the c2s with 25 gatorskins. the ride is much smoother than my old open pros, but a of that probably has to do with running a lower psi with the wider rims.


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## Slow Ride

SpecializedMok said:


> just another thing to mention: I recently purchased the HED Belgium C2 rims with Vittoria Open Pave tires (24mm tires). I like em compared to my Syrium Equipes. The ride is smoother and perhaps other people can chime in on this since if they've tried it as well...


I've tried 25c GP 4 Seasons on the HED C2 rim, and found the front tire squirms too much when I run the lower pressure I prefer. And higher pressure defeats the supposed purpose of that rim. 

A 23c Vittorio Rubino Pro works great on the front with lower pressure, and gives a good ride. I suspect any 25c tire could get squirmy on a C2 rim with low pressure [compared to a standard 19mm rim]. 

Honestly though I can get just a good of ride with a 25c tire on 19mm rim than with a 23c on a C2. Any future road wheels will likely have 19mm rims. Same performance, lower cost. The added weight of the C2 rim exceeds the weight difference between a 23 and 25 tire.


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## Fogdweller

This thread didn't take long to deteriorate.

OPer, I ride 25s on my commuter and 23s on the Sunday bike and can't tell a difference at all. Might be subtle difference but I can't perceive one.


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## rmsmith

Our county's road maintenance has really deteriorated over the past few years, so I bought a frame that uses the 57mm long reach Shimano R600 calipers, and I now run the Conti 4 Season 28mm folding tires. Going from 23mm to 28mm is noticeable.


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## PissedOffCil

I switched from 23 to 25mm tires this year. Doing so I was able to drop my tire pressure considerably in order to get some extra comfort. I now run my pressures around 90 in the back and 80 in the front. This is the pressure I used to ride in the rain but was always worried of flats (Although I never flatted). Normally in dry conditions I rode 110+.

The difference in feel definitely comes from the lower pressures as far as I'm concerned and larger tires allow lower pressures with less chances of flatting. That was the reasoning for my change in tire width. I'd like to try out some 28mm but my frame won't allow it, it's already very tight with 25mm. The fork could deal with 28mm but I'm not too worried about flatting in the front.


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## ZoSoSwiM

I rode 25mm GP4000's for 2 seasons.. Loved them.. Switched to 23mm Ultremo ZX's this year and they "felt" faster but resulted in a harsher ride. After destroying a pair of them I went back to my much cushier 25's.. dropped the pressure to 100 and now I'm still riding the same speed.. and I'm more comfortable. Based on this I'm sticking with 25's. They're just as fast as 23's and more comfortable so in the end they're actually faster.


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