road bike tyres ? which size

ngordon

i currentkly have 700 x 25 on , whats the difference between them and 700 x 23 ?? would i be better with 23 ?

interesting thread about the krylions - i have only had 3 months out of mine.

john74

im no expert but the 25s will be a little more comfy but slightly slower. i run 23c and after a couple of hours with potholes my arms really ache but ive never used 25s so it could be the same.

Mike67

Depends what you do with the bike really.

I've currently got 25s on for my Winter training as they are a tad more comfy than 23s, more volume/lower running pressure, especially with the roads in the condition they are.

The down side is they are slightly heavier than the equivalent 23. My Summer wheels have 23s on as I use them for the odd club TT etc., hopefully they will have filled a few holes in the road by then
Some guys go as low as 20s for this but I've never tried that.


The differences however, IMHO are not massive either way.

danowat

Got 23's on 3 sets of my road wheels, and they are good enough for winter conditions for me, never felt the need to go to 25's.

Got 21's on my TT wheels, great on smooth surfaces, not great on rough roads though.

Berk Bonebonce

I think 23's are what you would typically race and time trial on in the UK. The roads are that poor you are better off in terms of comfort and extra grip with 25c if you are a recreational/fitness type cyclist.

wildmoustache

23s have a very slight weight advantage (can be as little as 10g per tyre), and usually (though it depends on the rim) an aerodynamic advantage, which will almost certainly be be small in relation to total drag, though if you are optimising for a TT for example, worth considering.

In their favour 25s will have slightly lower rolling resistance, more grip and more comfort, this last one being the most significant of all the differences.

Note that different tyre types vary considerably in actual width despite having the same nominal width.

FWIW I think 25s are the better option for most riding except racing (including TTing) on smooth roads in the dry.

MarcBC

As a heavier rider, I was pointed in the direction of 25s. Apparently rider weight makes a difference to what feels best too.

vorsprung

25mm are more comfortable because they can be run at a lower pressure without any danger of pinch flats

If a 25mm and a 23mm tyre are run at the same pressure the rolling resistance (speed of the tyre) is about the same. The 25mm might be slightly better on rough surfaces and the 23mm is slightly more aerodynamic and lighter but there isn't much in it

Rouge Penguin

Who are 28's aimed at? Touring?

rick_chasey

Rouge Penguin wrote:

Who are 28's aimed at? Touring?

Looking cool on my fixie.

23s are fine and standard. Just run them at 6 bar and you'll be fine.

Monty Dog

25mm = more comfort and grip + less punctures, naff-all weight difference

Some people stalwartly insist on sticking to 23mm all year but thats probably because they haven't tried anything else and enjoy mending punctures.

BTW aerodynamic advantage of narrow tyres is negligible - rolling resistance is more important and in fact fatter tyres have reduced resistance over skinny ones (same tyre pressures etc).

pst88

Monty Dog wrote:

...fatter tyres have reduced resistance over skinny ones (same tyre pressures etc).

I always thought it was the other way round. Anyone have an explanation for this?

rolf_f

The idea is that, for a given pressure, the contact area will be the same whether you are on 23s or 25s. However, the fatter tyre will have a wider contact patch across the width of the tyre and a shorter one along the tyre. It is the size of the contact patch in the direction of rotation that determines resistance so therefore the fatter tyre has lower rolling resistance. Except you'll probably up the tyre pressure of the narrower one a little anyway. The higher aerodynamic wind resistance of wider tyres supposedly only cuts in at higher speeds.

I doubt it makes much difference - I use 23s and 25s and both seem fine but I am light. I think mostly people often prefer 23s because they look cooler.........

markos1963

23mm on my race/tt bike for lightness and aero
25front28back on my winter bike for grip and comfort(will fit 28mm on front when the 25 wears out)

Buckled_Rims

At the moment I've 23mm on th CAAD and 25 on the CX bike. I've experimented last summer with 23mm and 25mm on each bike, result....er, no difference in speed, 25mm slightly better handling, comfort and more puncture resistant.

I'm also more confident with 25mm tyres on gritted roads and bridlepaths.

Elio

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