23 vs 25 war

[andyfraser]

On my Long Haul Trucker, I went from 32c tyres to 42c. Granted, different makes, but it made chuff all difference to my average speeds.

That's what I've generally found. My road bike is faster than my hybrid but the tyres don't make any real difference at my level.

 

[jack smith]

I can't make my mind up. Where can I get some 24s to split the difference?

http://www.hargrovescycles.co.uk/sp...0LAl0igf9iDPtfHoJWXczGTEsMYaQhrRCrRoCW_7w_wcB

 

[the_mikey]

I can't make my mind up. Where can I get some 24s to split the difference?

There used to be Continental Grand Prix tyres in 24c..

 

[I like Skol]

I can't make my mind up. Where can I get some 24s to split the difference?

23c front and 25c rear, that should do the trick?

EDIT: A foot in each camp, as it were.

 

[Cycleops]

25s are a little more aerodynamic than 23s....

That's a good one!

 

[StuAff]

That's a good one!

Actually, depending on the rim width, that can be perfectly true.

 

[Erudin]

I can't make my mind up. Where can I get some 24s to split the difference?

http://road.cc/content/review/6226-continental-grand-prix-700x24c-tyre

"As a new addition to Continental's popular Grand Prix series of tyres, the Grand Prix 24mm is all about about, you guessed it, being 24mm wide, a miniscule increase over the girth of the common 700x23mm tyre but supposedly offering an increase in comfort and speed."

 

[Big_Dave]

You guys need to get with the program!

20c is where it's at......
This extract is from the 1990 brochure for the Raleigh road bike I have bought for my son. It is on 23c tyres at the moment but I am wondering if I should swap them to 20c for period correctness?

My old record sprint was on 20c, I was going to put my Kellogg's on 20c's (originally on 25c) but opted for 23c as there was more choice of tyres

 

[Fab Foodie]

I can't make my mind up. Where can I get some 24s to split the difference?

Vittoria open pave come in 24c and 27c. I have the latter

 

[Rob3rt]

25s are a little more aerodynamic than 23s and have virtually no rolling resistance difference. That is why pros are moving towards them.

If you want to extract the last 0.1% from your effort, use 25s. Otherwise ride whatever feels comfortable

The above is not strictly true. 25's tend to offer reduced rolling resistance and MAY offer improved aerodynamics IF they are mounted to a suitable rim so as to minimise bulbing and optimise the tyre-rim transition and enhance the overall rim profile. However, this is talking only about the tyre/wheel in isolation, put it in a bike with a rider on it and you might find the combo that was best in isolation is actually worse as part of the whole system.

Additionally, you might end up with a situation where a 25 offers lower rolling resistance, but is an aerodynamic compromise or vice versa.

I have field tested the following:

19mm Continental podium TT tubular on a FFWD Trispoke vs a 22mm Continental podium TT tubular on a FFWD Trispoke
The rear wheel was held constant, FFWD Disc with a 22mm Continental Podium TT tubular.

The aerodynamic advantage from the thinner tyre in my testing was MUCH larger than the rolling resistance increase, that is to say, even though the rolling resistance of the overall system increased a little, the CdA of the entire system decreased by an amount that far outweighed the increase in rolling resistance. I believe this to be for 2 reasons, in simplest terms, a lower frontal area, A, and a visibly better transition between the tyre and the rim, lower, Cd. If anyone is particularly interested I can provide ratios (I can not disclose absolute values).

That's a good one!

If you are going to mock, at least do it from a position of having a clue!

 

[I like Skol]

I thought putting the word 'war' in the title was a bit of a joke. Now I have read some of the replies I am beginning to fear for the future of humankind......

 

[Cuchilo]

I think my Conti 25c grandsport race are faster than my Schwalbe 23c ultremo zx but the 20c I tried on an old steel pug where faster than both . IMHO .

 

[I like Skol]

It may have slipped by me but nobody seems to have mentioned tyre weight? Isn't an equivalent tyre in 23c going to be lighter than the 25c and the 20c even lighter than both of them? And isn't this weight loss going to be at the very outside of the wheels circumference where it can have the maximum affect on performance and acceleration? Surely this overrides the aero and rolling resistance issues completely?

 

[Rob3rt]

It may have slipped by me but nobody seems to have mentioned tyre weight? Isn't an equivalent tyre in 23c going to be lighter than the 25c and the 20c even lighter than both of them? And isn't this weight loss going to be at the very outside of the wheels circumference where it can have the maximum affect on performance and acceleration? Surely this overrides the aero and rolling resistance issues completely?

Most of the resistance a cyclist is fighting to overcome is air resistance, as such aerodynamics are by far the greatest concern in most contexts.

 

[Cycleops]

If you are going to mock, at least do it from a position of having a clue!

Thanks Rob, but I'll leave that to you. By the way where did you cut and paste all that stuff from?