700x23 or 25 tyres?

[malverncyclist]

Hi
my old Raleigh TI road bike is in need of new tyres and I am pondering whether to fit 700x35 rather than the current 23 tyres. I assume that the rims can take 25 tyres, there should be enough vertical clearance at the frame end, but what would I gain/loose by riding either the 23 or the 25 tyre?

thanks

Martin

[meic]

Common sense says that you will not be able to tell the difference. The manufacturers are sometimes mis-label their tyres to that sort of degree anyway.

On the other hand 25mm is my lower limit, so even though I carry a 23mm as a spare tyre I would not use it except in an emergency.
Which isnt quite logical.

I suppose that I actually feel that 28mm is the smallest reliable size* but I am willing to take the risks of a 25mm tyre but it is already showing drawbacks of contact area and pinch punctures, so 23mm is just a step too far.


* for my riding situation.

[Mick F]

I was at 20mm for many years, then latterly I changed to 23mm.

I wouldn't go any wider as I don't think I could fit mudguards. 23mm is perfect whereas 20mm gave me pinch punchers every now an again.

I run Vittoria Rubino Pro tyres and they are fantastic. Light, supple and fast - and above all - puncture proof. I cannot remember when I last had a puncture - it's been absolutely years.

[Brucey]

it rather depends which 700x25c tyres you get. They often come up a size you don't expect, and obviously vary on different rims, too. I recently bought some training tyres in both 25c and 23c size (same make and model otherwise) and they finished up closer to 1mm different in final size instead of 2mm or more. But at least both were within 1mm of the nominal size, where many other tyres are not. IMOE Michelin tyres are likely to come up to the specified size quite closely, but I'm not so sure about other brands.

I personally believe there is a 'correct' -or at least 'optimum'- tyre size for each rim width; normally a road tyre ~20-25% wider (fitted) than the rim is about right. Tyres that are a lot wider or a lot narrower than this might be 'OK' most of the time but can produce weird handling, especially when cornering hard.

cheers

[andrew_s]

Some 25mm tyres will come up large (I've had 26.5mm), so if you are pushing the clearances you may be restricted on tyre model.

In general, the fatter tyre can be run slightly softer without risking pinch punctures (eg 100psi rather than 110psi, or 90 rather than 100)
The softer tyre is more comfortable with less bounce over rough roads, and will give better traction. Reduced bounce will reduce rolling restistance (on rough roads only).
If a fatter tyre is run at the same pressure as your 23mm tyre, there will be a little less rolling resistance.
A fatter tyre will have a little more aerodynamic drag.

I reckon the slight difference in comfort is the only thing you'd be likely to notice

[reohn2]

Hi
my old Raleigh TI road bike is in need of new tyres and I am pondering whether to fit 700x35 rather than the current 23 tyres. I assume that the rims can take 25 tyres, there should be enough vertical clearance at the frame end, but what would I gain/loose by riding either the 23 or the 25 tyre?

thanks

Martin

If theres enough room fit them it can only help with comfort.I don't know what rims you have fitted but they'd have to be a very narrow rim not to take a 25mm tyre.
IME Schwalbe and Continental come up approx one size smaller so 25's=23's
Michelin and Panaracer are about right size.
What tyres are you riding at the moment?

[Valbrona]

25s might offer you a smidgen more comfort and a smidgen more grip.

[willcee]

what tyre indeed.. firstly i'd consider the surfaces you are riding along. broken tarmac or as i say 3rd world roads where i live demand respect using 23's... despite that i had 1000 miles puncture and cut free use from a pair of pro 3 mich's , which i sold on to an impecunious chum!!! i run michelin carbons 23, vittoria paves 24, gatorskins,in 25 and 28, mavic 23's ys10, challenge 22's, certainly i consider weather and route at this time of year when going out.. i usually run 28's on winter's bad roads , 25's/24's winter dry road , spring and onwards 23's.. i'm not light weight , however i am careful, i rarely have flats, one in the last 3years, cuts or broken spokes.. my 2d's worth.. will

[Raph]

If your the sort of rider that always scans the road for road bumps and potholes and takes your weight off the saddle slightly (as if letting one rip, a passing motor passenger once remarked!), you can get away with thinner tyres - if you tend to sit your posterior's dead weight on the saddle and leave it there regardless what the bike goes over, then unless your roads are very smooth you need the tyres to offer a bit of padding. Your comfort and the bike's comfort sort of go together, i.e. anything that hurts your bottom potentially hurts the bike too.

Though - as mentioned above there's very little difference between adjacent tyre sizes, variation within a size is often more than between two adjacent sizes, so it's more a case of choosing tyres that look the right size! I'm never quite sure where they measure to and from, as it never adds up. If I line up all the tyres I have in the house in order of girth, the marked sizes will be in random order, give or take a few correct ones at the extremes. I have a 32mm Vredstein that's definitely thinner than a 28mm Conti, some 23mm Michelins that are about the same as a 30mm Pasela, it goes on...


PS off topic - 20mm tyres - I've tried some 20mm Ozzos and Hutchinsons, they really were thinner than all the others, and the extra vibration lost any advantage of less drag, if there even was any less drag to speak of. Also, picking a way through bad road surfaces and having noticeably worse traction made them a pain. 22-23mm seems to be a minimum, for me anyway, regardless how light the rest of the bike is.

[Brucey]

.....22-23mm seems to be a minimum, for me anyway, regardless how light the rest of the bike is.

call me slow-witted if you like but -some time trials excepted- it only took me about 25 years to come to that conclusion...

cheers