What is the point of 23mm tyres..

Bustacapp

...if 25mm roll faster?

Buckie2k5

im opening a can of worms here. More aero and less weight.

MartinB2444

Lighter, don't need as much clearance?

ju5t1n

BR published this a couple of years ago... http://www.bikeradar.com/gear/article/b ... ths-29245/

chrisvanderkaap

i'd like to see some firm proof of that. I've been testing both 25 and 23 mm tires on and off for 2 years now and I must say It really depends on the rim width as well. A 25 mm vredestrein fortezza tricomp tire 'bulges' (like a lightbulb) on my wife's 19mm campagnolo rims while the identical tire in 23 blows up wider and is more forgiving on my H+son archetypes (23mm). I think the need and want for 25 mm instead of 23 has come from the increase in rim width over the last years. My ten cents would be to match the right tires with the right rims.

ju5t1n

As per the link (and there are other studies if you Google for them) the research says 25mm is faster. It’s interesting because intuitively I would have expected 23mm tyres to be faster. And I still use them, despite having read that piece a couple of years ago - partly because the choice is better in 23mm and partly because of the clearance on my bikes. The clearance problem is a bit of a chicken and egg thing I guess.

GiantMike

Somebody will be on here in a minute claiming they can tell the difference in drag. Probably the same people who can tell the difference in stiffness between 2 different stiff cranks.

rolf_f

Well, for one thing, I don't weigh much so I can run lower tyre pressures and gain the same wider contact patch as a heavier person on a 25mm tyre running a higher pressure. All things being equal, if I was better off running 25s, then heavier people should be on 28s.

But it makes naff all real world difference either way as far as I can see. The make and model of the tyre makes more difference than 2mm overall width difference IMO.

PS My Ribble can't handle 25s under the Cruds either.

JayKosta

Where do you get the idea that 25s 'roll faster' than 23s ?

Yes, there are reports that 25s have less 'rolling resistance' than 23s - WHEN the 25s are inflated to same pressure as the 23s. But even that doesn't mean the 25s will actually roll faster.

Jay Kosta
Endwell NY USA

MattC59

It depends what you're comparing, my 23s measure in at 24mm.

napoleond

I find on 'normal' rims 23s are better in that they handle better than 25s. On wider rims 25s feel nice and smooth with less handling compromise. I have to say though 24mm Conti GPs or Vittoria Open Paves on 23mm wide rims are very pleasant.

AchillesLeftKnee

If find 23mm tyres extremely useful, especially when you discover those who've answered "Yes, your frame can take 25mm tyres" are in fact talking a load of arse, or have only used them on surfaces that have previously been meticulously hoovered. Under those circumstances, 23mm tyres are great, because they grip a ton better than rims, and also take a lot more sting out of the ride than bare metal.

Wirral_paul

JayKosta wrote:

Where do you get the idea that 25s 'roll faster' than 23s ?

Yes, there are reports that 25s have less 'rolling resistance' than 23s - WHEN the 25s are inflated to same pressure as the 23s. But even that doesn't mean the 25s will actually roll faster.

The article linked does suggest that the rolling resistance is lower and many therefore seem to assume that they are faster. The article however goes on to mention aerodynamics with the narrower tyres scoring better there. Seems that the combination of rolling resistance AND aerodynamics will dictate which tyre is faster when on a bike. Personally i doubt there's anything noticable in it between 23mm and 25mm in the real world - but the extra grip and comfort of a 25mm tyre has a certain attraction.

I'll be fitting 25mm tyres when i need replacements anyway.

Grill

I roll with 21mm on the front and 19mm on the rear @160psi... what up now! :P

iPete

I'm normally skeptical of saying 'what do the pros use', what with being used to promote the latest fan dangled products but in this case, 'what do the pros use'? Unless its the roubaix I assume they'll all be on 23s or smaller?

denniskwok

I think 25mm tyres are becoming the norm in the pro peloton these days.

gloomyandy

Nap do you happen to know what actual width the 24mm tyres end up when on a 23mm rim? My 23 Ultremos end up measuring 25mm. At some point I's like to try a 24 or 25 but not sure if I will have the clearance.

Sprool

JayKosta wrote:

Where do you get the idea that 25s 'roll faster' than 23s ?

Yes, there are reports that 25s have less 'rolling resistance' than 23s - WHEN the 25s are inflated to same pressure as the 23s. But even that doesn't mean the 25s will actually roll faster.

Jay Kosta
Endwell NY USA

The article compares different tyre sizes at the pressure that gives them the same loaded sag, about 15%, which means an average 25 takes 90 - 95 psi and a 23 takes 105 - 100 psi. The science is in the 15% sag level which minimises friction from elastic deformation / hysteresis. I think the real feel differnce is in riding a tyre that is a little softer. Round our way the lower chatter from a softer tyre on a bumpy road surface makes it feel like its grippier.

TakeTurns

I believe it's dependent on the rider what width they ride and also the terrain which one is riding on.

My clincher set up is 25 and 28mm. Relatively speaking, I weigh more than others. So the set up may seem outlandish. However, I find this set up better than 23mm. It's more comfortable and faster (I believe).

AchillesLeftKnee

TakeTurns wrote:

I believe it's dependent on the rider what width they ride and also the terrain which one is riding on.

My clincher set up is 25 and 28mm. Relatively speaking, I weigh more than others. So the set up may seem outlandish. However, I find this set up better than 23mm. It's more comfortable and faster (I believe).

Profoundly unscientific I know, but on the dodgier road surfaces of Surrey, I find my 26"er hardtail MTB (with the forks locked out) actually rolls very noticeably better (as in "quicker") on 38mm slicks with a breaker belt recycled from the Bismark than the road bike does on 23mm GP4000Ss. The extra volume just soaks up the roughness of the road rather than transmitting it though the bike and rider.

chrisaonabike

Grill wrote:

I roll with 21mm on the front and 19mm on the rear @160psi... what up now! :P

Do you wear a string and insist that's more comfy too?

binsted

So does anybody run 23mm on the front and 25mm on the rear............no scientific reason, just curious.

Grill

ChrisAOnABike wrote:

Grill wrote:

I roll with 21mm on the front and 19mm on the rear @160psi... what up now! :P

Do you wear a string and insist that's more comfy too?

To be fair that's only on my TT bike. Never had an issue with comfort though even on 12 and 24hr events.

AllanES

binsted wrote:

So does anybody run 23mm on the front and 25mm on the rear............no scientific reason, just curious.

I do on one of my bikes.
I asked the question here a few weeks back about mixing tyres/tyre widths (due to being old and remembering the days of not mixing cross ply & radial tyres on a car )
I guess the replies all said no problem with that whatsoever so I now have 23 on the front and 25 on the rear. Mainly for comfort reasons.
TBH I'm not sure I've noticed a significant difference.

junglist_matty

When brand new, my bike had 23mm Conti GP4000s tyres.... They were great for the first 600miles, no punctures what-so-ever, then the punctures started coming in slowly and eventually puncturing almost every ride, they seemed to wear thin fairly quick. I weigh 95kg and ran the tyres at around 110-120 PSI.... I loved them for their amazing grip and confidence in the tyre both in the wet and the dry, which for me, was a first.

I finally decided to replace them like for like after about 2500miles, but at the last minute decided to try the 25mm version.

I've had 1 puncture in about 1200miles of riding, and that puncture was a slashed tyre from a bit of glass that no decent (dare I say it, "race") tyre would have survived. I haven't noticed one blind bit of difference between the 23 and the 25, I've both beaten PB's I set on the 23's, and not (yet) beaten PB's I set on the 23's.

In the real world, if anyone tells you it makes a difference, they're lying. Unless your a pro cyclist putting out mega-watts of power, you won't notice any difference (I doubt they can even tell). If you did a blind test yourself, you wouldn't be able to tell which was the 23 and which was the 25 of any particular tyre (given it's the same model 23/25 comparison). Having a good day is the only likely factor to affect how you ride, not the tyre width choice.

some people like 23's because they have more clearance for mudguards, but other than that, in the real world, there's no difference at all; if you really fall for the marketing waffle and rely solely conclusions from unrealistic, uber-technical investigations then choose your tyre width based on that, at the end of the day it's personal choice, but I know I'm sticking with 25mm solely because they last longer for the same price and are totally insignificantly different to 23's.

gloomyandy

Matty, what tyre pressure are you running on your 25s? You should be able to run a lower pressure which would hopefully make for a slightly more comfortable ride.

fsman

From what I have read (as I want to upgrade my tires to GP4000s) it really depends on your weight and tyre pressure - and the brand.
there is a school of thought that if you are about 180lbs or less and riding on normal roads, then 23 is right. If you are on the more heavy side or poor road surface, then the 25 may prove better. But it is also linked to the tyre pressures too. i.e. a 100psi 23 and 25 will have different performance for different weight of riders.

Of course a wider tyre will naturally have more "give" and more air cushion. That can give more confidence etc. This debate is a bit like the "best saddle", no right or wrong answer. If you want a more racy saddle, get your sit bone measured and go for a skinny saddle (but it is a saddle not a seat), if you want a more comfy saddle, your'll get a wider, more padded saddle etc. But there is always a trade off.

I suspect this is going to be the same with the 23 vs 25 tyres. Different people, different weights, different conditions and different preferences.

My conclusion, I'm leaning towards 23. Why, coz I'm just over 11stone (and loosing a little more weight), I have a more racing vs. sportive bike, with family commitments etc. I ride 2-3hours. And I prefer the look of a narrow 23. This setup isn't going to hold me back from the Ridelondon100 next month. I don't ride my comfortable hybrid with its more comfy 28 tyres - I prefer my carbon racing bike - so 23 for me.

If I was doing longer rides on a regular basis, maybe I could consider the 25s. But I don't think I'm going to notice the difference vs. 23. But upgrading to a GP4000s - I'm expecting good things vs. my current stock ultrasports.

chris_bass

iPete wrote:

I'm normally skeptical of saying 'what do the pros use', what with being used to promote the latest fan dangled products but in this case, 'what do the pros use'? Unless its the roubaix I assume they'll all be on 23s or smaller?

i'd go with this train of thought really, the pro teams through so much money at testing and development that i'd go with them on issues like this!

fsman

also found this too.

Pross

I still think of 23s being quite wide, when I started off in the early 90s most people were on 19 or 20mm and a lot of people were TTing on 18s! Clearance is the biggest reason for me, also my 23s are difficult to get through the brakes when taking a wheel off even with the brake quick release fully open.

mpie

I must be doing something wrong then.
After a bit of experimentation, I run GP4000s 23s with ~80psi (front) and 90psi (back). Never had a pinch flat at that pressure despite hitting some bad potholes over the years. Much more comfortable (less rattley) that ~100psi. Weight has varied around 160lb over that time.
Pressure agrees (more or less) on two gauges.