23 or 25mm Clinchers to race and train? Which clinchers to choose?

by MattFr   July 22, 2013  

I know I'm going to get all sort of responses, but I'm currently thinking of going to 25mm tyres after a number of people have told me the advantages of the lower rolling resistance. What I'm wondering is would you use them for both racing and training? And I guess does rider weight (64kg) make a difference to tyre choice?
Also what would be the clincher of choice? In an ideal world I'd opt for an open tubular type for best, and a cheaper training tyre, but I'm not sure this is an option at the moment.

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I regularly ride 25mm or 28mm, and i'm no heavyweight (63kg).

More comfy than 23mm, in my admittedly limited experience. And they don't seem to slow me down.

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posted by PJ McNally [586 posts]
22nd July 2013 - 9:04

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If you want one tyre for both then open tubs are not the best option - you might be lucky but they would be best used as a racing tyre, with latex tubes.

Vittoria Corsa or Veloflex, with lovely gumwall sides.

For 25mm tyres which are good as training and racing I like Vredestein Fortezza. Continental do their GP 4000s in 25mm but I've never really been impressed with Conti.

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posted by abudhabiChris [517 posts]
22nd July 2013 - 9:23

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Double check frame clearance is enough for 28's first! Also some 25's have wider profile than others (Vittoria open corsa as mentioned in 25c appears a very wide and round profile,.it will only just fit in one of the bikes I've put them on..

Conventional wisdom is 23 for racing,.I understand. (I don't race), but comfort is not as much of a factor, they are a little lighter, plus unless you don't get the more aero limitations on conventional width rims (bulge of tire over and above brake track width)

Marginal gains and all that...

But this is just theory, and if you prefer to be comfortable you might find wider is more beneficial than narrow tires

posted by 700c [556 posts]
22nd July 2013 - 14:40

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KiwiMike wrote:
I swapped from 23 to 28 (Gatorskins) 6 months ago. Apart from only having had one flat in over 3,000km, I'm faster and have no more wrist/bum pain from vibration on poorly-surfaced roads. I follow the 15% drop rule - http://goo.gl/fkCwA - so for a 70kg rider + 10kg bike, I run 80psi rear / 50psi front.

This might be heresy to those who 'know' different, but the science says 15% drop and a larger tyre means same or lower rolling resistance, less fatigue, and fewer punctures.


That's very interesting; so you've not had any issues with pinch flats or damaged rims hitting the edges of holes with such low pressures?

posted by chrismday [49 posts]
22nd July 2013 - 16:38

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700c wrote:
Conventional wisdom is 23 for racing,.I understand. (I don't race), but comfort is not as much of a factor, they are a little lighter, plus unless you don't get the more aero limitations on conventional width rims (bulge of tire over and above brake track width)

Marginal gains and all that...

But this is just theory, and if you prefer to be comfortable you might find wider is more beneficial than narrow tires

No-one wins or loses because of 2mm of tyre width or 20 grammes difference in weight. Those gains are at the thinnest end of marginal. But a 25mm tyre does give you a greater volume of air so a little more comfort, though IME it's not 'night and day'.

Pressure can make quite a difference, mainly because too hard a tyre will be bouncing you and your bike around instead of deforming and absorbing surface irregularities. I'm 62 kg and for racing I put 100 psi in my Ultremos for smooth courses, 90 psi on the rougher ones. Was happy with ~80 psi in the 25mm Vittoria Rubino Pro 2s I had. I began racing club TTs on 28mm Bontrager Hardcase tyres (talk about making it harder!) and one night I forgot to check the rear - it was just 40 psi yet it didn't seem to make much difference!

If you were another 10 kg heavier I'd add 5 psi to those numbers but every rider should establish their preferred pressures.

More tyre suggestions - http://road.cc/content/forum/88042-help-tyre-choice

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posted by Simon E [1947 posts]
22nd July 2013 - 19:20

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Simon E wrote:
700c wrote:
Conventional wisdom is 23 for racing,.I understand. (I don't race), but comfort is not as much of a factor, they are a little lighter, plus unless you don't get the more aero limitations on conventional width rims (bulge of tire over and above brake track width)

Marginal gains and all that...

But this is just theory, and if you prefer to be comfortable you might find wider is more beneficial than narrow tires

No-one wins or loses because of 2mm of tyre width or 20 grammes difference in weight. Those gains are at the thinnest end of marginal. But a 25mm tyre does give you a greater volume of air so a little more comfort, though IME it's not 'night and day'.

Pressure can make quite a difference, mainly because too hard a tyre will be bouncing you and your bike around instead of deforming and absorbing surface irregularities. I'm 62 kg and for racing I put 100 psi in my Ultremos for smooth courses, 90 psi on the rougher ones. Was happy with ~80 psi in the 25mm Vittoria Rubino Pro 2s I had. I began racing club TTs on 28mm Bontrager Hardcase tyres (talk about making it harder!) and one night I forgot to check the rear - it was just 40 psi yet it didn't seem to make much difference!

If you were another 10 kg heavier I'd add 5 psi to those numbers but every rider should establish their preferred pressures.

More tyre suggestions - http://road.cc/content/forum/88042-help-tyre-choice

Well yes, hence the term marginal! The OP wanted to know the difference between 23 and 25 mm tires. That's a question about marginal issues!

On another note, I must be a bit mad running my tubs at 140psi! Higher for TTs, but it works for me..

posted by 700c [556 posts]
22nd July 2013 - 20:13

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700c wrote:
I must be a bit mad running my tubs at 140psi! Higher for TTs, but it works for me..

I have read that tubs roll well with higher pressures but I'd not want to race on Shropshire roads at that. A friend of mine is a bit lighter than me. She uses Conti tubs on her Navigators and doesn't normally go over 100 psi.

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posted by Simon E [1947 posts]
23rd July 2013 - 9:41

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for racing a narrower tyre is likely to be better than a 25. It depends on the wheel, but at racing speeds you will lose more speed through drag (maybe 5 watts) then you will save through lower rolling resistence (< 1 watt)

These are small differences, that you would never notice in training where comfort is more important, but there is no way in hell I would use a 25 for a TT.

posted by ilovemytinbred [164 posts]
23rd July 2013 - 12:12

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chrismday wrote:

That's very interesting; so you've not had any issues with pinch flats or damaged rims hitting the edges of holes with such low pressures?

Sorry, just saw this Wink

No pinch flats here, or on any of the club bikes running 28's at similar pressures.

I was told there would be Cake. Luckily there's http://TestValleyCC.org.uk

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posted by KiwiMike [474 posts]
31st January 2014 - 10:31

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In terms of volume 25mm tyres are around 18% larger and therefore can be run at around 20PSI less. The difference is certainly NOT marginal.

Gains on rolling resistance with 25mm tyres are certainly greater than 1W when tested on real roads, not steel drums. The worse the road surface, the more significant gains (largely thanks to lower pressure not width per se).

I don't follow trends. Trends follow me.

posted by BBB [180 posts]
31st January 2014 - 12:44

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chrismday wrote:
KiwiMike wrote:
I swapped from 23 to 28 (Gatorskins) 6 months ago. Apart from only having had one flat in over 3,000km, I'm faster and have no more wrist/bum pain from vibration on poorly-surfaced roads. I follow the 15% drop rule - http://goo.gl/fkCwA - so for a 70kg rider + 10kg bike, I run 80psi rear / 50psi front.

This might be heresy to those who 'know' different, but the science says 15% drop and a larger tyre means same or lower rolling resistance, less fatigue, and fewer punctures.


That's very interesting; so you've not had any issues with pinch flats or damaged rims hitting the edges of holes with such low pressures?

That is interesting, I run 28s on my commuter bike and have found 80psi on the rear about right for the rear just by trial, error and feel - which more or less tallies with the chart. I tend to run the front higher than the 60 recommended there though, too many deep, sharp edged potholes to risk lower.

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posted by joemmo [798 posts]
31st January 2014 - 14:19

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Moved from Continental GP4000 23c to Continental GP4000 25c last year.

The only difference I've noticed is the increased comfort.

posted by levermonkey [362 posts]
31st January 2014 - 16:36

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levermonkey wrote:
Moved from Continental GP4000 23c to Continental GP4000 25c last year.

The only difference I've noticed is the increased comfort.

Exactly the same here

posted by VeloPeo [219 posts]
31st January 2014 - 16:42

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ilovemytinbred wrote:
for racing a narrower tyre is likely to be better than a 25. It depends on the wheel, but at racing speeds you will lose more speed through drag (maybe 5 watts) then you will save through lower rolling resistence (< 1 watt)

These are small differences, that you would never notice in training where comfort is more important, but there is no way in hell I would use a 25 for a TT.

Yup. There's an informative discussion by the lead engineer at Zipp on how going from 23 to 25 will marginally decrease your rolling resistance and save you ~0.3 watt but the increased air resistance 0-6 watts can penalize you. They're still in the 23 camp, esp since the tire rims have to be bigger for the wider tires further increasing your drag.

http://velonews.competitor.com/2012/03/bikes-and-tech/technical-faq/tech...

For winter tires I've switched to 25 Continental GP 4-season (great traction and puncture resistance, Portland roads are wet, filled with debris with some brick paving thrown in for fun) and run 23 Vittoria Rubino Pro III in the summer although just bought some Veloflex Corsa's to try cuz I've heard such great things about them. Vittoria & Veloflex used to be the same people but Vittoria split off and sent their production to Thailand and Veloflex is still handmade in Italy and cheaper. Used to ride Vittoria Evo Corsa 23s which are very fast and corner well but punctured like crazy and didn't wear well, just 500-700 miles which is too expensive (for me) to be replacing them that often.

Melancholy is incompatible with bicycling. ~James E. Starrs

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posted by movingtarget [134 posts]
31st January 2014 - 22:36

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There was a very interesting article by Richard Hallett on this very subject. I think it was in last week's Cycling Weekly, but it might have been the week before.

As I recall it, he comes down in favour of 25s on the grounds of lower rolling resistance and greater comfort than 23s.

posted by Kadenz [41 posts]
31st January 2014 - 23:04

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get some 30s. Challenge are making some nice ones Wink

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posted by Dave Atkinson [7324 posts]
31st January 2014 - 23:11

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It's an old topic, but too fun to not comment, and someone else did post today...

Yes, a one-wheel solution is inherently a compromise, but in the less elite race categories, the gap between riders will be more significant than differences in their equipment. You can worry about equipment way too much. I hope that the original poster got his 25s.

When you do get a set of race wheels, you can stop worrying about making your training wheels "fast." Horses for courses. Wheels that don't get raced can be heavier, more durable, and more comfortable.

There is a category of rider who wants fast training wheels to "win" training rides or century rides. Apart from triathletes, they must be the people buying carbon clinchers. A coach and a power meter might make them faster, but who am I to say that their form of recreation isn't valid?

posted by 53x11 [7 posts]
1st February 2014 - 0:48

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25's will fit in my Planet X ProCarbon, but you have to inflate them once they are in the frame & you can't fit guards then (not even CrudRacers), so I'm limited to 23's for the winter. But as I don't have wide rims, that isn't bothering me too much.

Currently going slower than I'd like...

posted by stealth [186 posts]
1st February 2014 - 21:35

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I'm thinking of doing similar, what pressures did you run the 23's at when compared with the 25's?

Specialized Allez 2009, Campagnolo Centaur 10, Campagnolo Shamal Wheels. 8.3kg

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posted by Miles253 [199 posts]
2nd February 2014 - 13:38

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Tyre pressure. Since changing to Continental GP4000 25C have reduced tyre pressure by 25 to 30psi depending on conditions.

posted by levermonkey [362 posts]
4th February 2014 - 16:54

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levermonkey wrote:
Tyre pressure. Since changing to Continental GP4000 25C have reduced tyre pressure by 25 to 30psi depending on conditions.

***30***? you sure?

maybe on a 52c, but a 25?

I was told there would be Cake. Luckily there's http://TestValleyCC.org.uk

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posted by KiwiMike [474 posts]
4th February 2014 - 17:20

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Sorry. I didn't make that clear.

Reduce pressure by 25psi OR 30psi depending on conditions. Even reduced by 30psi I've still got 140psi in the tyre.

In my defence I was a bit rushed and didn't proof read before submitting.

posted by levermonkey [362 posts]
6th February 2014 - 7:46

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levermonkey wrote:

Reduce pressure by 25psi OR 30psi depending on conditions. Even reduced by 30psi I've still got 140psi in the tyre.

According to the science http://janheine.wordpress.com/2010/10/18/science-and-bicycles-1-tires-an... you must weight around 130kg Wink

I was told there would be Cake. Luckily there's http://TestValleyCC.org.uk

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posted by KiwiMike [474 posts]
6th February 2014 - 8:42

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levermonkey wrote:
Sorry. I didn't make that clear.

Reduce pressure by 25psi OR 30psi depending on conditions. Even reduced by 30psi I've still got 140psi in the tyre.

In my defence I was a bit rushed and didn't proof read before submitting.

Blimey, you might want to look at those pressures - apart from a lack of comfort, they are way over the max pressures for the tyres. GP4000 is listed as 125PSI max and the GP4000s 120 PSI, unless i'm reading that wrong.

If you're using them on the boards then I could understand the high pressure a little more, but then again you wouldn't be using 25mm GP4000's there. Can I ask what sort of riding you do that makes it worth the risk and ride quality ?

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posted by fukawitribe [376 posts]
6th February 2014 - 9:53

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Trust me they will take higher pressures. I'm a lot heavier than 64kg and have managed to compress a race tyre to the rim hitting a bump. Also my road bike is not my everyday, it's a weekend and sportive special. 140psi is an absolute maximum on dry, smooth roads - as you can guess you don't find them in UK. UK roads max 130psi for 23C, 100-110psi for 25C.

posted by levermonkey [362 posts]
6th February 2014 - 19:41

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All this talk of 10psi here or there. I have two track-pumps. A Bontrager and an SKS. They give different readings, by just over 10psi. I'd say any pressure quoted here should be taken as a guide only, they go out a bit harder, then a bit softer and see what feels right. You'll know when it's right. And your bum will thank you.

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posted by Low Speed Wobble [138 posts]
7th February 2014 - 8:39

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Sorry for resurrecting this thread again but just read an article on 23 vs 25 based on the pro's perspective that people might find interesting. And there's some tire pressure thrown in there at the end just for some spice.

http://www.competitivecyclist.com/learn/25-vs-23?cmp_id=EM_CC_1067218_S1...

Would be interested to find out what the OP ended going with.

Melancholy is incompatible with bicycling. ~James E. Starrs

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posted by movingtarget [134 posts]
14th February 2014 - 21:13

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Interesting link.

The pro's might be on 25's, but then they've got the latest super wide rims which are designed to work with wide tyres (ie no bulge over the rim, preserving the aerodynamic advantage of deep section wheels)

I can't afford to update my summer 'aero' tubulars, which are the traditional narrow v shape, so I stick with narrower tyres as per the manufacturer recommendations.

Possibly it wouldn't make much difference anyway, but then that would defeat the object of buying deep, light carbon wheels in the first place..!

posted by 700c [556 posts]
15th February 2014 - 0:23

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Comparisons of pro's riding tubular 23s and 25s are hard to quantify when looking at clinchers - a tubular 23 is a tubular 23, it gets glued on, inflated and that's that. When you look at a clincher, things like air volume, tyre width etc become dependant on your rim width, base tape thickness, double layered base tape, tyre bed profile etc. so one persons experience on a 25 clincher might be very different to another's.

Just get the ones you want to try, and try them. If you like them, buy more.

posted by Nick T [805 posts]
15th February 2014 - 10:09

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If I were ever to do the type of riding where I could appreciate the benefits of aero carbon wheels it would be nice. They are sooo aesthetically appealing.

I found the last bit of the article the interesting though. I've heard so many different people and reviewers say that wider rims and wider tires = lower air pressure. So with a 23 mm rim, your 23 mm tire actually balloons out to 25 or even 27 mm but then instead of 100 psi or whatever you normally run at (yes, yes, long-standing debate) they drop down to 70 or 80 psi which makes for a cushier ride but takes away some of the rolling resistance benefit from the wider tire-road interface which no one really mentions.

Now if I could just get all the science to convince the spouse to let me upgrade my wheelset ....

Melancholy is incompatible with bicycling. ~James E. Starrs

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posted by movingtarget [134 posts]
16th February 2014 - 0:21

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