700x23 or 700x25 tryes. whats the pro's and con's

rob39

Hi all
Rode all my life on 700x23 tryes. I don't race anymore just ride for fun and enjoyment and wondered if there would be any benefits in changing to 700x25 tryes. ???? Advice welcome

John.T

They give a bit smoother ride. If you ride on mainly good surfaces there is not much difference but they are better on poor roads. Just as fast on them as well. I fit them for the Tour of Flanders sportive a few years ago and they made a big difference on the parve.

Wooliferkins

Bit more volume in the tyre giving a bit more cushioning, on the other hand a bit heavier.

balthazar

I much prefer 25's. It doesn't seem like 2mm could be much difference, but they're detectably more comfortable and no slower rolling. They feel more secure on bumpy downhill corners where they are less inclined to skip across the tops of road features. If I could fit them in my bike I'd go for 28mm for more of the same; alas, I can't.

Headhuunter

I actually prefer the sense of speed, lightness and sense of contact with the road you get from 20mm (or less) tyres, but unfortunately they're not particularly easily available so I end up with 23mm. 23mm are noticeably spongier.

Monty Dog

You get at least 20% more volume in the tyre for negligible weight penalty - 30g typically - means you can run tyres at a lower pressure for better grip and comfort. I was converted years ago having spoken to someone who ran a pro-team in Belgium - they always laugh at the UK riders who turn up with 23mm tyres pumped to 120psi, get loads of punctures and crash on the corners in Kermesses because of poor grip. It's also a complete fallacy that skinny tyres are faster - it's been posted / discussed so many times here, I can't be bothered to even give an explanation.

mattward1979

Monty Dog wrote:

You get at least 20% more volume in the tyre for negligible weight penalty - 30g typically - means you can run tyres at a lower pressure for better grip and comfort. I was converted years ago having spoken to someone who ran a pro-team in Belgium - they always laugh at the UK riders who turn up with 23mm tyres pumped to 120psi, get loads of punctures and crash on the corners in Kermesses because of poor grip. It's also a complete fallacy that skinny tyres are faster - it's been posted / discussed so many times here, I can't be bothered to even give an explanation.

No offence, but can this be backed up?

Just got my road bike with 700x23's and very interested in the science that backs up the physical entities.

gkerr4

I thought 23's were the best comprimise tyre.

I have 28s on my winter bike - they are comfy but they ruin the 'light' feeling in the wheels.

John.T

http://sheldonbrown.com/tyres.html
Read Sheldon's article. It covers most things mentioned here.

balthazar

mattward1979 wrote:

No offence, but can this be backed up?

Just got my road bike with 700x23's and very interested in the science that backs up the physical entities.

http://www.sheldonbrown.com/brandt/roll ... bular.html

Here's an old experiment but a resolutely pertinent one. It shows that RR trends aren't closely related to tyre width. The best and the worst are both 28mm; a given 20mm is middling.

mattward1979

balthazar wrote:

mattward1979 wrote:

No offence, but can this be backed up?

Just got my road bike with 700x23's and very interested in the science that backs up the physical entities.

http://www.sheldonbrown.com/brandt/roll ... bular.html

Here's an old experiment but a resolutely pertinent one. It shows that RR trends aren't closely related to tyre width. The best and the worst are both 28mm; a given 20mm is middling.

fair enough! wasnt deliberately being a douche. just as a scientist like a bit of science to backup my science!

Harry182

Sorry to go off topic but thanks to this thread and its Sheldon Brown link I've just spent over an hour internet researching the myth of "Talcum Powder for Tubes and Tires". (see - http://www.sheldonbrown.com/brandt/talcum.html )

I used to talc with religious fervour.

BTW - consensus seems to be that talcing the inner tubes does not lower rolling resistance (as I had been lead to believe) nor does it help prevent punctures. Talcing may, however, make installing the tyre and inner tube easier.

(At least I already knew about not over inflating my tyres - http://www.sheldonbrown.com/tyres.html#pressure .)

Headhuunter

Monty Dog wrote:

You get at least 20% more volume in the tyre for negligible weight penalty - 30g typically - means you can run tyres at a lower pressure for better grip and comfort. I was converted years ago having spoken to someone who ran a pro-team in Belgium - they always laugh at the UK riders who turn up with 23mm tyres pumped to 120psi, get loads of punctures and crash on the corners in Kermesses because of poor grip. It's also a complete fallacy that skinny tyres are faster - it's been posted / discussed so many times here, I can't be bothered to even give an explanation.

I know it's been endlessly discussed but to me they certainly feel nippier and firmer and at 120psi you're likely to get fewer punctures than at a lesser pressure not more. There is also a noticeable difference in cornering which feels sharper and responsive.

On tyre pressure, I have heard that much more than 120psi in your tyres is counter productive however as the tyres are so hard that they cannot absorb small imperfections in the road surface and bounce up and down rather than roll over them.

balthazar

mattward1979 wrote:

fair enough! wasnt deliberately being a douche. just as a scientist like a bit of science to backup my science!

Not at all. This stuff is still counter to most people's expectations. There is some good data swimming around in the opinion sea.

John.T

To go slightly further off topic, disregarding pinch flats, why should tyre pressure make any difference to liability to punctures if using sensible pressures say between 90psi and 120psi. Once the thorn or bit of glass has stuck to the tyre it will work through anyway. Most of my punctures are as a result of something I ran over some miles back. Or if lazy some days ago that I should have checked for.

sampras38

Headhuunter wrote:

Monty Dog wrote:

You get at least 20% more volume in the tyre for negligible weight penalty - 30g typically - means you can run tyres at a lower pressure for better grip and comfort. I was converted years ago having spoken to someone who ran a pro-team in Belgium - they always laugh at the UK riders who turn up with 23mm tyres pumped to 120psi, get loads of punctures and crash on the corners in Kermesses because of poor grip. It's also a complete fallacy that skinny tyres are faster - it's been posted / discussed so many times here, I can't be bothered to even give an explanation.

I know it's been endlessly discussed but to me they certainly feel nippier and firmer and at 120psi you're likely to get fewer punctures than at a lesser pressure not more. There is also a noticeable difference in cornering which feels sharper and responsive.

On tyre pressure, I have heard that much more than 120psi in your tyres is counter productive however as the tyres are so hard that they cannot absorb small imperfections in the road surface and bounce up and down rather than roll over them.

That's pretty much my understanding too, and I tend to ride my 23's at around 110.

jedster

I use 28mm on my commuter. I tend to run them at 110 too. As far as I can see the only disadvantages vs a 23 are
a) weight but I'm carrying a fairly heavy panier, rack, guards, dyno hub so additional tyre weight is not bvery siginificant
b) aesthetics - but again on a commuter I don't think that's an issue, on a race bike maybe

robthehungrymonkey

Why do the pros run at 130psi if there's no benefit?

balthazar

robthehungrymonkey wrote:

Why do the pros run at 130psi if there's no benefit?

If they do, it's for lower rolling resistance. The graph in the article I linked to demonstrates that higher pressure=lower RR.

John.T

robthehungrymonkey wrote:

Why do the pros run at 130psi if there's no benefit?

Do they. Probably only on tubs which have different RR characteristics. They ride the tyres best suited to the conditions they will meet in a particular event. Most of us can not do that so we compromise. 23mm being considered to be the best compromise by many. 25mm for rougher roads. These are for race and sportive type bikes. Optimum pressures should depend on rider weight and manufacturer's recomendations.

robthehungrymonkey

John.T wrote:

robthehungrymonkey wrote:

Why do the pros run at 130psi if there's no benefit?

Probably only on tubs which have different RR characteristics.

that's a good point, i hadn't thought of that.

It was from Cadel Evans on twitter during the tour.

Monty Dog

Hysteresis is the magic word - these are the energy losses from the deformation of the tyre carcass whilst rolling - a narrower tyre deforms more for the same given pressure that a wider one, hence is less efficient. The 'footprint' of a narrower tyre is different too - the wider tyre affords more grip. Tyre width impact on aerodynamics is negligible - regardless what testers will have you believe. A number of tyre makers have done the research. Above about 7 bar, the effects of pressure are negligible - harder tyres are more uncomfortable, puncture more easily and grip less.

John.T

a narrower tyre deforms more for the same given pressure that a wider one, hence is less efficient.

But you should not be using the same pressure. A better measure would be the same footprint area which is controled by tyre size, pressure and weight applied. Using optimum pressures there is very little difference in RR or grip between tyres of similar construction but different sizes. Tyres above 25mm will usually have heavier construction so should not concern us here. The main differences are in how the tyre rides. The 20mm will feel more lively but harsher. The 25mm a little more dead but more comfortable. As for differences in speed you would probably not be able to measure them.

gkerr4

i recently tried my 23mm Open corsa Evos at the full 140psi

was hell

- really really uncomfortable - back to 120psi now at which they feel great.

jedster

A better measure would be the same footprint area which is controled by tyre size, pressure and weight applied

wrong actually, footprint area is defined only by weight and pressure - area x pressure = weight.

Of course the SHAPE of the footprint is influenced by tyre width - narrow tyres will have longer thinner footprint of the same area for same weight and pressure.

These longer thinner footprints roll less well.

BazookaMoor

Definitely recommend 25mm for comfort.

Been riding a good aluminium frame for a couple of years on Michelin Krylion carbon 23mm tyres and been reasonably comfortable on 40 - 50 mile rides.

However a few months ago the Michelin Krylion 25mm tyres came back into stock after a lengthy absence and I bought a pair to see if there was a difference.

The answer for me is a big resounding yes.


I used to think that I needed more comfy shorts and a better saddle, now I don't really notice much discomfort at all.


For the record, I weigh 80kg and run the front at 85 psi and the back at 100 psi


Hope this helps

rob39

Can anyone recomend a good 25mm trye, with usual stuff of low rolling,light and good puncture resistance.

skyd0g

Would rider weight be a consideration in the 23/25 comparison? My thought is that as I'm a lighter rider, I don't need as much "cushioning" as a heavier rider might?

Headhuunter

skyd0g wrote:

Would rider weight be a consideration in the 23/25 comparison? My thought is that as I'm a lighter rider, I don't need as much "cushioning" as a heavier rider might?

The wider the tyre, the lower the air pressure it is possible to stick in it without it bashing up and down on the rim, so I suppose a larger rider may go for a wider tyre at a lower pressure for cushioning.