[Closed] 25c road tires much more comfy than 23c's ?

I certainly noticed a difference going from 23c @ 110pis to 25c @ 90psi with no discernible extra drag.

Edit: be aware it's likely you'll need to change the tubes too.

There is an appreciable difference

They'll definitely feel different. Reckon they roll a bit better. As for comfort, I didn't find 23c uncomfortable and I don't find 25c uncomfortable either.

23c @ 110pis to 25c @ 90psi

Probably no different to just running the 23c at 90psi.

Edit...

You won't need new tubes unless you run latex.

Put some 23mm latex tubes in my 25mm tyres a couple of rides ago. They seem ok so far. Am I on borrowed time? 😕

Run your pressuers a bit lower and see how it feels, I notice the difference.

You won't need new tubes unless you run latex.

Can't say I've noticed much difference going from 23 to 25, but noticed a big difference going to 28's.

The Mavic tyres are very good (Yksion Pro); I commuted on them this morning. But they are a narrow "23c". I have the same tyre on another wheelset in 25c and yes, they are more comfortable. But the difference for these tyres is not as large as some other brands. The Mavic 25c are more like Schwalbe's 23c, for example, and I raced on the 25c on my Handbuilt CXP33 rims last night, just as a reference point (cornering was pretty squirrelly if anyone is interested)

I've recommended them many times, but for speed. comfort, cornering, Schwalbe's new One in 25c is the very best tyre I have ridden. The difference to your Mavics will be night and day, and a significant upgrade for a new road bike rider.

I made the switch last year, and have not regretted it. As well as improving comfort they are also are less skittish. I regularly descend (& climb back up - no circuits around here!) a 12% hill with a slight kink on the way down. I reckon the change to 25c tyres is worth about 2mph on my max speed, which is generally 45 - 50 depending on conditions.

Still on 23mm tyres and find difference between makes. Schwalbes that came on one bike, I thought were OK, then went to Vittoria and were so much more comfortable. Also on my nice bike have Michelin Pro 4's . Seems its down to rims and frame type as well. Deeper rims will always make the ride more jarring. I would hazard a guess at 25mm making it more grippy in the bends tho'. May try a pair of 25's when I wear some tyres out.

Probably no different to just running the 23c at 90psi.

Not in ride quality, no, unless you are a riding God, pinch flat resistance though...? And latex tubes may stretch, I'd heard they don't, I was just covering myself.

speed. comfort, cornering, Schwalbe's new One in 25c is the very best tyre I have ridden

How have you measured these? Tested the grip till you lost it? Same in corners? Speed tested eliminating all other variables?

Or are you recommending what you've recently bought?

I guess if your switching 23 to 25 and using a different tyre then you can't differentiate what made the difference. I went 23 to 25 on conti gp 4 seasons and as I said no discernible difference. But there are so many other variables that for me it would be very hard to pin down what's making any difference.

Tested the grip till you lost it? Same in corners? Speed tested eliminating all other variables?

Or are you recommending what you've recently bought?

No, I've raced over 1000 laps of Hillingdon circuit on a collection of tyres in a variety of conditions. (In both directions).

That list in full;
Schwalbe Durano S (23c) - pretty good base tyre
Schwalbe Ultremo (23c) - lighter faster more fragile
Schwalbe One (23c and 25c) - both great, but 25c are more comfortable
Mavic Yksion (23c and 25c) - nice tyres, narrow for width

Also Giant pslr tyres in 23c (rather good, nice round profile), wore them out last season.

Rims are Open Pro, CXP33 (both narrow 19mm), Giant pslr aero (23mm) and some generic Giant wheels (again 19mm).

Inner tubes have ranged from generic Schwalbe to Conti Hypersonic and more recently latex. I have of course ridden these tyres for commuting, club runs, other road and circuit races and the occasional time trial. But you asked for reproducible, and Hillingdon is my testing ground. Experimental design is part of my job, but it's normally people not tyres 😉

I don't like Continental tyres.

Ah okay, so all subjective then.

Indeed, but cornering speed and confidence is noticeably different on the 25c Schwalbes compared with the 25c Mavics. This is certainly down to tyre profile. All other design parameters being constant (including weather).

Vittoria are next on the list.

How are all other parameters the same on different tyres?

You are saying only the width matters?

You presumably run the narrower tyres at higher pressure which will make them feel less grippy?

[i]I don't like Continental tyres.[/i]

I do, but only gp 4 seasons on my commuters. Used grand prix 24mm for a few months but felt a bit fragile

Interesting that you're going for Vittorias next - open corsa cx I presume? I've been using these for a few years and they're fantastic, even better with latex tubes.

I'm going for shwalbe ones for a change at next tyre change, which will be next month.

How are all other parameters the same on different tyres?

You are saying only the width matters?

You presumably run the narrower tyres at higher pressure which will make them feel less grippy?

Vittorias next - open corsa cx I presume?

Another recent convert to Vitoria Open Corsa CX's here, 23mm as my bike cannot fit a larger tyre at the back.

Interested to know what difference to latex tubes make as I've got normal ones in at the moment.

Lighter, faster rolling, more supple, more puncture resistant (allegedly). Lose 10 PSI a night, harder to install without pinching, noisy on the road. Try them.

Never noticed any additional road noise from latex tubes, 'noisy on the road' in what way, rumbling?

Ah okay, so all subjective then.

But not viewed from an armchair.

Lighter, faster rolling, more supple, more puncture resistant (allegedly). Lose 10 PSI a night, harder to install without pinching, noisy on the road. Try them.

A couple of rides in and I like them so far for the reasons mentioned above. No pinches when installing, don't seem to be any more fragile than a really light butyl tube. Though I did get one split along the seam when inflating which was a bit annoying (I put it down to being a 22-23 in a 25mm tyre.)

I've switched for my winter tyres, definately a bit lezz buzz even at the same pressure. About the same feeling as switching to a comfier frame. My summer wheels are stans rims so 23's bulge out to about 25 anyway.

MrSmith - Member
Ah okay, so all subjective then.
But not viewed from an armchair.

And from your armchair view you have utterly missed your point.

Hmmm gone up £2.50 since I bought them:

http://www.merlincycles.com/continental-grand-prix-gt-folding-road-tyre-70152.html?utm_campaign=googlebase-GB&utm_source=googlebase&utm_medium=shopping&utm_term=Continental+Road+Tyres&gclid=CMfAqanRmb8CFYjjwgod2SYAtQ

And from your armchair view you have utterly missed your point.

Lol.

Ah okay, so all subjective then.

"Comfy" is a really subjective thing anyway.

I'm surprised no one has built a rig for this sort of testing with a power meter and motor. You could do speed at different powers with different pressures and weights. Maybe "comfort" with some sort of vibration sensor. Hmm I feel an arduino project coming along 🙂

They have
[img] [/img]

[i]"Comfy" is a really subjective thing anyway.[/i]

You're right and any changes to the bike are very difficult to quantify as there are so many other variables. Even if you do the same route to 'test' a new component the ride could be affected by weather, what happens on the ride, your mood and how you generally feel that day.

mrblobby some tyre mfrs have produced rolling resistance data IIRC.

MrSmith - Member
And from your armchair view you have utterly missed your point.
Lol

Oops I meant "my point". No idea what yours is here.

They have

I like 🙂

You're right and any changes to the bike are very difficult to quantify as there are so many other variables.

It's also what you're looking for. Been riding 25c wheels for a few weeks now and I couldn't tell you if they were any more "comfy" than 23c as that's not what I was interested in.

mrblobby some tyre mfrs have produced rolling resistance data IIRC.

I'm guessing there is no agreed standard (weights, pressures, road surface, etc.) between manufacturers on how to do this though.

About the same feeling as switching to a comfier frame

at a somewhat lower cost!

Right, off to purchase and try out some latex tubes.

Don't forget to double check your data before submitting your report.

OP - You don't mention if you're actually uncomfortable on 23c?

Personally I find 25c much more comfortable, and they also give me a better feeling cornering.

But check with manufacturer if your frame can take them first!

[i]Personally I find 25c much more comfortable, and they also give me a better feeling cornering.[/i]

I take it you're using the same tyre but just in a different width?

My original reason for trying 25c was to achieve a more tubular profile, which I thought would help with faster, more confident cornering on crit circuits - so I switched Schwalbe Ones from 23c to 25c (a crash rendered the 23c unrideable anyway). I also think that rolling resistance over the small imperfections in this country's great roads would benefit from a larger contact patch. So I switched Mavic 23c to 25c. With this nice mix, I decided to mix them up and just try to see if I could detect differences when racing. I still commute on Open Pros with 23c Mavics.

Rolling resistances testing is done on a smooth drum rather than the A315 Staines Road. I'm sure that 19 mm tyres at 125 PSI mounted on Mavic's narrow rims (Ksyrium, Open Pro, CXP33) rolling over France's perfect smooth roads will be more aero and faster than 25c. But here in the real world, the larger tyres will have a larger contact patch, which is less sensitive to minor surface deviations (29ers?)

Latex tubes have less hysteresis loss and roll and deflect more easily than butyl. One of the effects I noticed when I swapped Hypersonic butyls for Michelin latex (with Ultremo 23c tyres at 110 PSI riding the Preston Park Circuit) was an immediate increase in noise. I have very sensitive hearing - as tested by Mrs TiRed; who was an audiologist 😉

I guess the above makes me a little sad!

Probably no different to just running the 23c at 90psi.

At 90psi my 23c tyres felt draggy and a bit twitchy on corners - also got my one and only pinch puncture when hitting a relatively small pothole.

This shows pressures to achieve suggested optimum wheel-drop/deflection of 15%:

[img] [/img]

I take it you're using the same tyre but just in a different width?

You take it correctly.

TiRed - Member
My original reason for trying 25c was to achieve a more tubular profile

Interesting - contrary to the trend for wider rims.

I also think that rolling resistance over the small imperfections in this country's great roads would benefit from a larger contact patch

You increase contact patch by lowering pressure only (tyre width is irrelevant) which you say you kept constant?

You seem to misunderstand this at a very basic level.

Wide and narrow rims have both been tested using 23c and 25c tyres of the same brand. Contact patch size is not solely determined by pressure. I do not maintain the same pressures for road riding.

I have yet to run a full incomplete block factorial design using Hillingdon strava segment timings as the endpoint. But I am happy to analyse any data you may have using the most appropriate statistical methodologies.

You seem to misunderstand this at a very basic level.

[img] [/img]

Contact patch size is not solely determined by pressure.

What other factors and how?

I do not maintain the same pressures for road riding.

Ah. I was going on your earlier post where you said they were utterly consistent in your testing.

What other factors and how?

[img] [/img]

Rim width will also influence the shape of the contact patch and the tyre profile, but I have no peer reviewed scientific data to back that up 😥

You've not answered the question.

I know, I was hoping you would indulge us with the correct answer.

I've already done so.

A 25c will have a larger cross sectional radius, and a slightly larger overall radius. It is this that I think helps with rolling over imperfect surfaces. For racing at Hillingdon, I use the same pressures (Hard!) for all tyres as the surface is perfect. For road riding, commuting etc, I use a slightly lower pressure for 25c (100/105 PSI). I've flatted two Open Pro rims this winter with Mavic 23c tyres, despite 120 PSI (and no pinch flat). More rubber may have helped but they were both big potholes.

The Schwalbes have a very nice tubular-like cross-sectional profile in 23c and 25c. The mavics are more "U" shaped, especially the 23c, and I think that, adjusting for other factors including rim width, this is the biggest difference. They make something of compound as well, but all nice tyres roll well.

Can't say I've noticed much difference going from 23 to 25, but noticed a big difference going to 28's.

My Michelin Pro4 in 25c are the same width as Continental Gatorskins in 28c.

I was merely pointing out that contact patch shape was another factor as it hadn't been mentioned previously and that rim width also influenced the shape of the contact patch.
There's some interesting research from zipp where the different attributes start to cancel each other out and if you go too big it upsets the swirl behind the tyre and how it interacts with their rim profile and creates more drag than you are gaining by lowering rolling resistance.

http://inrng.com/2013/04/reinventing-the-wheel-25mm/

http://www.competitivecyclist.com/learn/25-vs-23

http://velonews.competitor.com/2012/05/news/giro-tech-rise-of-the-25c-tire_218011

http://velonews.competitor.com/2012/07/bikes-and-tech/technical-faq/technical-faq-wide-rims-light-bulbs-and-quonset-huts_232490

Just put on some vittoria pro from chain reaction. £20 each.

Off to work in a bit so I'll see how they feel.