23mm -v- 25mm Tyres

Cee-Jay-Cee

I'll be buying new tyres for my good bike in the coming months and swapping the part worns on to my winter bike. I've always stuck to 23's as they were the most common tyres for the last while and the size that came on both bikes when new, however now with all the reviews and data showing a marked increase in comfort coupled with lower rolling resistance with 25mm tyres, I'm contemplating them however no 25mm tyres are actually 25mm wide with the two (Michelin Pro4 SC and GP4000S II's) I'm considering measuring very close to 28mm wide when inflated.

I'm currently running Pro4 SC's on my good bike and they measure 23.7mm wide when inflated to 100psi on Zondas. I have a pair of well worn Michelin Krylions on my winter bike which are 23.3mm when inflated to 90psi (also on Zondas)

I'd like to try GP4000's in 25 but slightly hesitant at the thought of them being 28mm wide. I have the clearance on my bike...I think (Felt F5) so if there was clearance issues I can return the tyres or sell them here/adverts.

I've read the reviews and the results on http://www.bicyclerollingresistance.com/ but I'm just not convinced.

I run the Pro4 SC's at 90F/100R and theyre pretty comfortable although can be very jarring harsh on poor surfaces.

Opinions, advice, experience?

G1032

Will the 23mm GP4000's inflate to 25mm :-)

RobertFoster

I run 23s in the winter to allow for mudguard clearance, and 25s in the summer for comfort. If it wasn't for the mudguards, I'd run 25s all year.

LpPepper

I had 23s on my bikes and switched to 25s at the same time on both, instant improvement in comfort, haven't noticed any negatives

Eamonnator

I have Continental Grand Prix 4000s II, 25 mm on Mavic R sys wheels.
With 110psi in the tyres, they measure 27mm or thereabouts.
They are lovely, very comfortable and roll really well.
I would highly recommend them
Bike Palast have them at a good price, at the moment



http://www.bike-palast.com/en/Racebike/Tires/Tires/Continental-Grand-Prix-4000-S-II-black.html?listtype=search&searchparam=continental%20grand%20prix%204000

darkvalley

I've 25mm gp 4000s II on Zondas. They are measuring 26.7 at 100psi and 26.78 at 90psi
25mm gp 4seasons are measuring 27.1 on Bontrager race rims and 26mm on open pros. I know you didn't want that last piece of information, but I bought a digital calipers in Aldi last week and it is the first sensible things I have thought of to measure!!

jon1981

My 25s measure just shy of 28mm pumped up to as close to 120psi as I can get with my crappy old track pump. Would you not be running the risk of punctures and pinch flats operating at 90psi-100psi ? Seems awfully low

Unknown Soldier

Just to add a bit more confusion, some wheel manufacturers have changed their ETRTO size width to make the tyre/wheel combo even more "comfortable" The 2016 mavic Ksyrium Elites are: 622x17C and used to be 622x15C

Makes the tyre wider, apparently, and thus more comfortable. In fairness, a lot of the reviews are highly positive about the science.

It's possible DT Swiss started this ball rolling with their DT SWISS R 23 SPLINE 2015 on the Canyon Endurace last year. The Wheel/Tyre combo got rave reviews.

The speed/resistance aspect seems to come from looking at the wheel/tyre from the side.

Cee-Jay-Cee

darkvalley wrote: »

I've 25mm gp 4000s II on Zondas. They are measuring 26.7 at 100psi and 26.78 at 90psi
25mm gp 4seasons are measuring 27.1 on Bontrager race rims and 26mm on open pros. I know you didn't want that last piece of information, but I bought a digital calipers in Aldi last week and it is the first sensible things I have thought of to measure!!

Thank you so much. This is the information I needed!

Think I'll give them a go!

G1032 wrote: »

Will the 23mm GP4000's inflate to 25mm :-)

Apparently not, they're roughly around 23.8mm

Cee-Jay-Cee

Eamonnator wrote: »

I have Continental Grand Prix 4000s II, 25 mm on Mavic R sys wheels.
With 110psi in the tyres, they measure 27mm or thereabouts.
They are lovely, very comfortable and roll really well.
I would highly recommend them
Bike Palast have them at a good price, at the moment



http://www.bike-palast.com/en/Racebike/Tires/Tires/Continental-Grand-Prix-4000-S-II-black.html?listtype=search&searchparam=continental%20grand%20prix%204000

How much is postage? CRC have them at €39 a tyre inc postage so unless Palast had free postage then I'd get them from CRC.

Eamonnator

Postage is €9.90
Total cost €77.70

I got some tubes as well, postage was the same, made it more worthwhile.

crosstownk

jon1981 wrote: »

Would you not be running the risk of punctures and pinch flats operating at 90psi-100psi ? Seems awfully low

OP is using Michelin Pro4 SC which have a stated recommended pressure of 5 to 7.5 bar (75 to 109 psi) for 25mm.

I use these tyres quite a lot and usually inflate both to 7 bar (100ish psi) and I've never had a pinch flat.

tigerboon

jon1981 wrote: »

My 25s measure just shy of 28mm pumped up to as close to 120psi as I can get with my crappy old track pump. Would you not be running the risk of punctures and pinch flats operating at 90psi-100psi ? Seems awfully low

Depends on the combined weight of you and the bike. I normally go with about 95psi on the back and about 85psi on the front for 25s. No issues with pinch flats.

jon1981

tigerboon wrote: »

Depends on the combined weight of you and the bike. I normally go with about 95psi on the back and about 85psi on the front for 25s. No issues with pinch flats.

Do you use your pump gauge to measure the pressure or a special tool for that?

Cee-Jay-Cee

Eamonnator wrote: »

Postage is €9.90
Total cost €77.70

I got some tubes as well, postage was the same, made it more worthwhile.

Bullet bit...plumped for them from CRC....wouldn't be right to pass CRC for the sake of €1.

tigerboon

jon1981 wrote: »

Do you use your pump gauge to measure the pressure or a special tool for that?

Pump gauge. There's a calculator for it you can Google.

mossym

Eamonnator wrote: »

Postage is €9.90
Total cost €77.70

I got some tubes as well, postage was the same, made it more worthwhile.

2 delivered from rose bikes for 72 including postage,got some a couple of weeks back.

Eamonnator

mossym wrote: »

2 delivered from rose bikes for 72 including postage,got some a couple of weeks back.

Now you tell me.

mossym

Eamonnator wrote: »

Now you tell me.

sorry, posted as soon as i saw the thread. had posted a few time in other threads about the price at rose.

Eamonnator

mossym wrote: »

sorry, posted as soon as i saw the thread. had posted a few time in other threads about the price at rose.

I know. I don't know how to use those smiley thingies.

Cee-Jay-Cee

Fitted the GP4000's (25mm) on my Zondas last night. Also fitted a pair of Vittoria latex (18/23) tubes and inflated rear to 90psi and front to 80psi. The rear tyre measures 25.8mm wide and the front 25.5mm wide but they've gained nearly 10mm in height. Haven't been for a spin yet so can't comment on comfort yet.

I think I'll increase the pressure to 95/85 R/F for maiden spin on them and adjust accordingly up/down afterwards.

On a side note I've dropped 50g overall weight by (70g reduction from tubes and 20g gain with 25mm tyres) so it's all good so far.

MB Lacey

mossym wrote: »

2 delivered from rose bikes for 72 including postage,got some a couple of weeks back.

Thanks, I'm ordering some new 4000s also.
First stop was SCR to try and shop local, for a pair they were €88 delivered, Wiggle were €81 delivered, Palast /CRC were similar and now you've mentioned Rose selling for €72 (I can only manage €74.85) so will buy from Rose.
I have never ordered from Rose and would usually buy 23mm, but going to go for the 25mm.

So this is what living life on the edge feels like.

seanino

Hi,
I also have this 23 versus 25 dilemma. I do sportives, weekly spins and will start some racing soon. I want to upgrade my wheels so wondering would I be better going with campag zondas with 23 tyres or Mavic krysium elites which come with 25s. I don't really want to compromise speed but if the mavics with wider tyres have less rolling resistance than I think Id prefer them for comfort. Any options or advice please?
Thanks

G1032

seanino wrote: »

Hi,
I also have this 23 versus 25 dilemma. I do sportives, weekly spins and will start some racing soon. I want to upgrade my wheels so wondering would I be better going with campag zondas with 23 tyres or Mavic krysium elites which come with 25s. I don't really want to compromise speed but if the mavics with wider tyres have less rolling resistance than I think Id prefer them for comfort. Any options or advice please?
Thanks

Why can't you put the 25's on the Zondas?

seanino

I could but they are a narrow wheel and I think you might get the light bulb shape effect! there was a fairly compelling article I read online saying not to stick more than 23s on a narrow wheel like the zondas if I can track it down.

Cee-Jay-Cee

seanino wrote: »

I could but they are a narrow wheel and I think you might get the light bulb shape effect! there was a fairly compelling article I read online saying not to stick more than 23s on a narrow wheel like the zondas if I can track it down.

I'm after putting 25's on my Zondas and they do not bulge in fact the tyres only measure 25.8(R) and 25.5(F) when inflated.

G1032

seanino wrote: »

I could but they are a narrow wheel and I think you might get the light bulb shape effect! there was a fairly compelling article I read online saying not to stick more than 23s on a narrow wheel like the zondas if I can track it down.

I have 25's on Zondas. No issues with the tyres.

cromcruach

seanino wrote: »

I could but they are a narrow wheel and I think you might get the light bulb shape effect! there was a fairly compelling article I read online saying not to stick more than 23s on a narrow wheel like the zondas if I can track it down.

I've only ever run 25mm Open Pave on my Zondas. They are very close to exactly 25mm when measured, and with latex tubes the wheel/tyre combination is fast and gloriously comfortable. There's a much bigger lightbulb effect on my other bike, which has 28mm Schwalbe Durano on a 17mm internal rim width.

ednwireland

I run 25mm rubino pros normally find they take a small amount of road buzz out.
Got 25mm velo flex master tyres once the club tt's start

TheBlaaMan

From Sheldon Brown....
http://www.sheldonbrown.com/tire-sizing.html

[HTML]
Georg Boeger has kindly provided a chart showing recommended width combinations:

Which tire fits safely on which rim?
[all dimensions in millimeters]

Rim \ tyre
.......18 20 23 25 28 32 35 37 40 44 47 50 54 57
13 X X X X
15 X X X X
17 X X X X X
19 X X X X X X
21 X X X X X X
23 X X X X
25 X X X X X


Note: This chart may err a bit on the side of caution. Many cyclists exceed the recommended widths with no problem.[/HTML]

Zondas are 15mm internal rim width

jon1981

TheBlaaMan wrote: »

From Sheldon Brown....
http://www.sheldonbrown.com/tire-sizing.html

[HTML]
Georg Boeger has kindly provided a chart showing recommended width combinations:

Which tire fits safely on which rim?
[all dimensions in millimeters]

Rim \ tyre
.......18 20 23 25 28 32 35 37 40 44 47 50 54 57
13 X X X X
15 X X X X
17 X X X X X
19 X X X X X X
21 X X X X X X
23 X X X X
25 X X X X X


Note: This chart may err a bit on the side of caution. Many cyclists exceed the recommended widths with no problem.[/HTML]

Zondas are 15mm internal rim width

I guess that chart proves they can safely take a 25 or 28 but does it consider the Aero side of things?

SetOverSet

cromcruach wrote: »

I've only ever run 25mm Open Pave on my Zondas. They are very close to exactly 25mm when measured, and with latex tubes the wheel/tyre combination is fast and gloriously comfortable.

I'm running this exact combination for about a year now. The ride quality is amazing.

All My Stars Aligned

seanino wrote: »

I could but they are a narrow wheel and I think you might get the light bulb shape effect! there was a fairly compelling article I read online saying not to stick more than 23s on a narrow wheel like the zondas if I can track it down.

Just on this, I've been running 25's on narrow rims (Navigator Pista's) for over a year now with no issues.

On the subject of tyre pressure. I'm quite nervous about running low pressure, currently about 115 psi. Anyone know how low I could go, I'm 13st :eek: .

C3PO

All My Stars Aligned wrote: »

Just on this, I've been running 25's on narrow rims (Navigator Pista's) for over a year now with no issues.

On the subject of tyre pressure. I'm quite nervous about running low pressure, currently about 115 psi. Anyone know how low I could go, I'm 13st :eek: .

At 13 stone I would run 115-120psi on 23s.

seanino

unfortunately I can't post urls but Google intheknowcycling and tyre width and you will find the article. He recommends not to use more than 23s on zondas. So have you only ever had the 25s on zondas or had 23s . How did they compare? Thanks

Cee-Jay-Cee

All My Stars Aligned wrote: »

Just on this, I've been running 25's on narrow rims (Navigator Pista's) for over a year now with no issues.

On the subject of tyre pressure. I'm quite nervous about running low pressure, currently about 115 psi. Anyone know how low I could go, I'm 13st :eek: .

I was out for a short 25km spin today. I'm 12st and inflated them to 90R/80F and they were absolutely spot on so I think I'll stick with that combo.

cromcruach

seanino wrote: »

unfortunately I can't post urls but Google intheknowcycling and tyre width and you will find the article. He recommends not to use more than 23s on zondas. So have you only ever had the 25s on zondas or had 23s . How did they compare? Thanks

A lot of interesting reading there!

The only 23s I've run in recent years have been stock Zaffiro, which aren't in the same league as any 25 mm tyre I've bought at many times the price. Mind you Zondas aren't particularly aero so I think it's all marginal gains for those going flat out. Averaging 27-28 kph I'm not worried about 2 mm more overlap.

I can say I've put over 5000 km on a pair of latex tubes and they're still going strong, so can't agree with his reservations on latex for training. I can spare a minute before each ride to properly inflate the tyres.

superlav

A bit late but FWIW there is a pretty good deal on www.bike-discount.de

2 x Conti GP 4000 s II's with 2 x Conti Race tubes's for €75.90 delivered

seanino

So from a speed perspective but if there's a chance not to affect that and get comfort my choices are:

- Mavi Kyrsium Elites comes with 25s

- Zondas with 25s (conti gp 4000)

- Zondas with 23s (conti gp 4000)

Any recommendations?

Cheers

mossym

this may be of interest given the discussion

http://flocycling.blogspot.ie/2016/04/flo-cycling-a2-wind-tunnel-tire-study.html


flo cycling have released a new version of their wheels, and have done significant tyre testing in conjunction. the results shown are aero results only, so the 23mm 4000's come out ahead of the 25mm, but the 25mm don't do too bad at all.

the important bit to bear in mind is that the strength of the 25mm's is in the rolling resistance, which is not taken into account here but is coming in part 2, so i'd suspect they'll make up the ground there.

ford2600

mossym wrote: »

this may be of interest given the discussion

http://flocycling.blogspot.ie/2016/04/flo-cycling-a2-wind-tunnel-tire-study.html


flo cycling have released a new version of their wheels, and have done significant tyre testing in conjunction. the results shown are aero results only, so the 23mm 4000's come out ahead of the 25mm, but the 25mm don't do too bad at all.

the important bit to bear in mind is that the strength of the 25mm's is in the rolling resistance, which is not taken into account here but is coming in part 2, so i'd suspect they'll make up the ground there.

Aerodynamic drag is proportional to Area but proportional to velocity squared.

If they took 20mph (8.88m/s) rather than 30mph(13.33m/s) as the wind speed the difference between various tyres would be much smaller by a factor of 2.25.

For ordinary lads on here worrying about a 2mm tyre difference and aerodymanics is majoring in the minors I would think?

mossym

ford2600 wrote: »

For ordinary lads on here worrying about a 2mm tyre difference and aerodymanics is majoring in the minors I would think?

for sure. it was more to alert people to the testing, as i reckon more might be interested in the rolling resistance in part 2 when it comes. the chances of me remembering to post it when it is done are pretty low!!

even if the absolute numbers mean nothing to most, knowing a 25mm tire has lower rolling resistance while offering better comfort should be of interest i would have thought.

Cee-Jay-Cee

darkvalley wrote: »

I've 25mm gp 4000s II on Zondas. They are measuring 26.7 at 100psi and 26.78 at 90psi
25mm gp 4seasons are measuring 27.1 on Bontrager race rims and 26mm on open pros. I know you didn't want that last piece of information, but I bought a digital calipers in Aldi last week and it is the first sensible things I have thought of to measure!!

I pumped my tyres to the same pressures last night and mine are 25.5mm on the front and 25.8mm on the rear. My Zondas are a year old so 2014/2015 model. I'm using Vittoria 19/23 latex tubes so maybe that accounts for the slightly narrower width (measured with digital calipers)

jethrothe2nd

I'm still struggling to make a decision on whether to get 23s or 25s. Right now I have 23s on the stock Bontrager wheels that came with the bike. Realistically for someone like me who commutes a couple of days a week, a decent cycle at the weekend and the odd sportive here and there, is it going to make any difference to me whatsoever?

saccades

I'd say so.

I'm coming from an MTB background but I cycle ~150km a week on a road bike.

mtbs have been going tubeless, lower pressure and wider for a while now and with good reason.

The smoother the road, the harder you can have the tyre (and be narrower), and have no ill effects - that rolling resistance website above uses a steel drum (in effect a perfectly smooth road).

However in ireland few roads are perfectly smooth for very long :rolleyes:. So you are looking for tyres that can deform to bumps in the road which which does 2 things.

1 - stops you wasting energy going up and down and not forwards.
2 - stops you getting bumped about and getting beat up.

As an extreme example look at the lads in flanders - they used to run a Pave, bigger volume (24c or the 27c in latter years), 320tpi (incredibly flexible) and at a lower pressure because the tyres deform to take the hits.

In short, incredibly smooth roads and not bothered about some discomfort - 23c at 110psi+.

Anything else, a really flexible tyre with volume to deform at a lower pressure.

I'm not talking about 2.5 inch muddy mary 29'ers, they are way too far the wrong way, but a decent spec folding tyre (28c ish) at a lower pressure.

Cee-Jay-Cee

jethrothe2nd wrote: »

I'm still struggling to make a decision on whether to get 23s or 25s. Right now I have 23s on the stock Bontrager wheels that came with the bike. Realistically for someone like me who commutes a couple of days a week, a decent cycle at the weekend and the odd sportive here and there, is it going to make any difference to me whatsoever?

I was out for the first proper spin on my 25's today (I also fitted latex tubes) and I have to say the difference is very noticeable on poorer surfaces where the Tarmac is starting to break up. On 23's at the same pressure is have to get out of the saddle as the ride would be so jarring and rough but the 25'a/latex tubes soaked most of the harshness up which also meant didn't have to slow down so the overall spin was faster.

If you need new tyres, I'd recommend trying 25's

jethrothe2nd

Yis were dead right. I got GP 4000ii 25's and there is a massive difference all round.

benneca1

Anyone got any experience running 28s on standard rims. I got a front wheel blow out today cornering hard on a descent. Running new conti GP 4000 at 80 psi on Ksyrium sl wheels. I am wondering if tyre rode off the rim under pressure. Any thoughts anyone ? First time ever a front tyre blew out on me.