23 or 25 mm tyres ?

ExcitingHat

I have a Viking Torino bike with 23 mm tyres.

Would changing them to a 25 mm tyre make much a difference to my ride ?

Thanks

AndyD2574

I use 25's on my winter bike and 23's on my summer bike.

Slightly bigger contact patch for censored roads and more stable.......so they say!

ExcitingHat

Do you notice any difference ?

John.T

25s are smoother on poor road surfaces. Probably little difference in rolling performance. Just make sure there is enough clearance for them. If you have 4mm then no problem.

eyebee

I switched from 25's to 23's and noticed no difference whatsoever. Obviously theres a little more road contact the larger the tyre,but just make sure you have decent tyres.

twotyred

I've gone the other way and switched from 23mm to 25mm summer and winter. More comfort and the larger tyre runs better over rough surfaces. Buy a decent folding tyre and there will be negligible weight penalty.

Barteos

For non-competitive riding 25mm or even 28mm (same tyre) will be faster than 23mm.
The difference in speed will be practically undetectable but at 5-10 PSI less, they will be more comfortable.

AndyD2574

ExcitingHat wrote:

Do you notice any difference ?

Difficult to say mate as my summer bike is carbon and my winter bike is aluminium.

I just feel safer with 25's on the censored roads and I run my winter tyres about 10 psi sofetr than my summer. 110 psi on my summer bike and 95 - 100 on my winter.

k-dog

I do find them a little more comfortable - not a great test though as I got a much better tyre in the 25mm size too.

bluesparx

I have been running on 23s this winter and i just switched to a 25 on the front this week. I don't know about speed yet but it definitely feels safer on the roads.

twotyred

For non-competitive riding 25mm or even 28mm (same tyre) will be faster than 23mm

So do 23mm tyres become become magically faster when you're racing?

Monty Dog

2 myths: narrow tyres are quicker and higher pressures reduce rolling resistance.

The determinant factor is often the road surface and given the state of our rough roads, a narrow hard tyre is just more uncomfortable and will puncture more easily. Air resitance has negligible influence and anything above 110psi is generally pointless.

markos1963

I started with 23mm on my winter bike and I'm now running 28's, very little difference in performance but a big increase in comfort. If you got the clearance then give it a go. The main thing is quality, a good 25mm tyre will be faster than a cheap and nasty 23mm.

Barteos

twotyred wrote:

For non-competitive riding 25mm or even 28mm (same tyre) will be faster than 23mm

So do 23mm tyres become become magically faster when you're racing?

Choice of tyres depends on aplication.

23mm is a pro racing standard because it makes the best compromise between rolling, weight and air drag.

A typical bloke riding for fitness on some bad UK roads at 15-18mph doesn't have to worry about the weight or air resistance and most certainly will be faster comfier and safer on wider rubber thanks to reduced rolling resistance, lower pressure and larger footprint.

I think it's time that we abandon the oversimplified view of rolling resistance as a simple function of a contact patch area (narrower and harder is better :roll: ) and forget about the "that's what the pros use" nonsense and consider improved rolling of wider rubber as a fact, not speculation or theory.

rick_chasey

Pfft, stick to 23s.


It's the pressure that makes the difference, not the tyre width.

You only need wider tyres if you want to run lower pressures.

Then again, most people on this forum overinflate their tyres anyway.

Monty Dog

Rick Chasey wrote:

It's the pressure that makes the difference, not the tyre width.

I'm afraid you've just failed tyres 101 because it is the shape of the tyre carcass that does make all the difference. There's been plenty of published research on the subject & suggest you start on the Conti tyres website..

rick_chasey

Monty Dog wrote:

Rick Chasey wrote:

It's the pressure that makes the difference, not the tyre width.

I'm afraid you've just failed tyres 101 because it is the shape of the tyre carcass that does make all the difference. There's been plenty of published research on the subject & suggest you start on the Conti tyres website..

Really? to comfort?

Links please.

Also - forgive my scepticism from research published by a tyre manufacturer. Presumably it's in their interest to have tyre with differentation?

Berk Bonebonce

25mm tyres and reduced pressures are a good way to get a smoother ride. Let's face it, road surfaces in the UK are plain bad.

Monty Dog

http://en.wikipedia.org/wiki/Rolling_resistance

Can't find the original article - it was well publicised at the time but the conclusion was the biggest factor on rolling resistance was hysteresis - simplicitly: tyre deformation. Fatter tyres deform less for the same pressure and therefore lose less energy. Air resistance has negligible impact. The shape of a tyre patch also has a bearing on grip - a wider tyre has a broader contact patch and therefore more resistant to shear forces i.e. improved grip too. Finally bigger air pocket also improves comfort and reduces incidence of impact punctures.

alfablue

See http://www.schwalbe.co.uk/shopdata/file ... fo2-GB.pdf pages 16 and 17, to sum up, at "leisure speeds" (20kph) rather than racing speeds, the fatter tyre will roll better.

rick_chasey

Monty Dog wrote:

http://en.wikipedia.org/wiki/Rolling_resistance

Can't find the original article - it was well publicised at the time but the conclusion was the biggest factor on rolling resistance was hysteresis - simplicitly: tyre deformation. Fatter tyres deform less for the same pressure and therefore lose less energy. Air resistance has negligible impact. The shape of a tyre patch also has a bearing on grip - a wider tyre has a broader contact patch and therefore more resistant to shear forces i.e. improved grip too. Finally bigger air pocket also improves comfort and reduces incidence of impact punctures.

I'd suggest that the performance difference between 25mm and 23mm is minimal, and the biggest impact on comfort, is the pressure which you run it at, which probably varies a lot more than the marginal gains or losses from a 25mm to a 23mm.

If we're going to go down the physics route, I'd imagine that the marginal gain from having a 25mm is probably negated by a) more air resistance and b) more mass to rotate.

Even on UK roads there's no reason to ride less than 6bar, unless you're doing some Roubaix stuff, and that's perfect for a 23mm tyre.

Berk Bonebonce

alfablue wrote:

See http://www.schwalbe.co.uk/shopdata/file ... fo2-GB.pdf pages 16 and 17, to sum up, at "leisure speeds" (20kph) rather than racing speeds, the fatter tyre will roll better.

Spot-on.

Maybe one day the industry will learn that 26" is a much better option for commuter/leisure bikes than 700c. Hybrids suck.

lae

Bicycling Science (generally regarded as the best book ever written about bicycle physics) also confirms that tyres up to about 32c have lower rolling resistance, but obviously much more weight and aerodynamic drag. Aerodynamics is obviously less important the slower you're going.

It's all about the 28mm!

Barteos

Like many other discussions about rolling resistance, rotating weight etc, this one is also pointless, as some people are simply not able to accept and understand arguments based on science, test results and other people's experience.

The evidence is there. All it takes is some brain power and ability to think independently, regardless of what B.S. one is fed with by magazines, manufacturers, forums and the club mates.

Rick Chasey wrote:

Even on UK roads there's no reason to ride less than 6bar, unless you're doing some Roubaix stuff, and that's perfect for a 23mm tyre.

Some would say that if you need as much as 6bar, then your tyres are too narrow.
Anyway, thanks for telling us what we need

BazookaMoor

For me 25mm is alot comfier than 23mm.

I've got the same brand of tyre (Michelin Krylion) in both widths.

Unfortunately because of the tight clearances on my Cannondale CAAD 8 frame, I can't run 25mm tyres with Crud Roadracer mudguards so I have to use 23mm during the Winter months.

On crappy road surfaces the 23mm tyres give some discomfort after 3 hours or so, whereas back in the summer rides of 60 or 70 miles were fine.

If you can fit 'em buy some 25's


8) 8) 8)

dulldave

Your bike looks better with 23mm tyres so buy them.

Lagavulin

24mm?

springtide9

Lagavulin wrote:

24mm?

LOL...

Question....

Have my first outing on the road tomorrow and it looks like it's going to be wet.

My bike has Continental Grand Prix (24mm) tyres which currently have 120psi (as that's what's written as recommended on the tyre). I'm a road virgin (MTBer)
I know there are different versions.... so it's this one..
http://road.cc/content/review/6226-cont ... 0x24c-tyre

Looks like I need to remove a little bit of air. What pressure range do these tyres have and what would be recommended?

I'm sure I'll work it out over time (and will take it easy tomorrow)... but a ballpark psi figure would be good.

Thx

Old Tuggo

alfablue wrote:

See http://www.schwalbe.co.uk/shopdata/file ... fo2-GB.pdf pages 16 and 17, to sum up, at "leisure speeds" (20kph) rather than racing speeds, the fatter tyre will roll better.

That is 12.5 mph, I am sure most of us ride faster than that.

P_Tucker

twotyred wrote:

For non-competitive riding 25mm or even 28mm (same tyre) will be faster than 23mm

So do 23mm tyres become become magically faster when you're racing?

It's not magic - you go faster so aerodynamics are more important.

Stone Glider

@ Old Tuggo: errr..... no. This is still 'Road Beginners' isn't it? Whilst lots of posters like to tell us of their marvelous speeds, the records of Sportives, as quoted by the wise NapD, tell a different tale

As far as tyre wall recommendations, they are about the manufacturer covering their [email protected] in case of claims rather than offering advice to neophyte pedallers. Depending on your weight, about 100 should be fine for most. More in the back, less in the front. Try it out, adjust to suit.