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-   -   30c Vs. 23 Or 25c (https://www.bikeforums.net/road-cycling/1179607-30c-vs-23-25c.html)

Sasquatch16 07-31-19 01:24 PM


Originally Posted by WhyFi (Post 21051908)
Tying in to another thread, and telling you something that you probably won't like to hear - my Domane with 30mm tubeless is actually more comfy than my gravel bike with 38s. You should really go down to the shop and take a peek at one :D

Looking to go tubeless and put 30's on my Domane. What tires are you running?

WhyFi 07-31-19 01:43 PM


Originally Posted by Sasquatch16 (Post 21053699)
Looking to go tubeless and put 30's on my Domane. What tires are you running?

G-One Speed. Awesome tires.

Sasquatch16 07-31-19 02:30 PM

Thanks

alcjphil 07-31-19 06:23 PM

Asking a bunch of questions when you are new is a very good idea. What I take issue with is that you open a new thread for each new question. Makes it difficult to follow your thought process. I have had to look at multiple threads to try and figure out where you are going. Honestly, my head is spinning trying to follow your timeline. Is this question newer than the last question you asked? Was it older? You seem to be fixated on the idea of racing in the future. Don't look at road bikes with 10 speed cassettes unless you want neutral support cars that only have 11 speed wheels to be unable to help you. Doesn't matter if the bike you look at is a dedicated race bike, many races have been won on good bikes that were designed for less competitive events. A bike designed for criterium racing would fare badly at Paris Roubaix. For a newcomer, a bike designed for Cyclosportifs,(Gran Fondos) is an excellent beginner's race bike. These are the sort of bikes pros use for races like the cobbled classics.

woodway 07-31-19 07:58 PM

RE: Are wider tires slower? This link is a good discussion backed up by real world testing. FWIW, Bicycle Quarterly is a worthwhile publication.

https://janheine.wordpress.com/2018/...es-are-slower/

Seattle Forrest 07-31-19 10:49 PM


Originally Posted by CliffordK (Post 21053671)
One thing that should be pointed out is that a quality low rolling resistance 32mm tire is probably close to the rolling resistance of the average 25mm tire.

I think you either have that reversed, or mean aerodynamic resistance.

Branko D 08-01-19 04:58 AM

If 23s or 25s are uncomfortable, you're probably just running too much pressure in them. Unless you're a really heavy guy - which does warrant bigger tires - they work just fine with much lower pressures than people actually use. That's going to cause a bit of extra rolling resistance on fine roads, but actually lower the rolling resistance on really bad surfaces. The reason to use 23s is for aerodynamics: you want the rim external width to be 105% of actual tire width for best aerodynamics. Only modern high end aero rims are wide enough to accomodate 25s and 28s properly.


I run 23 in front and 25 in rear, and if I'm aiming for a comfortable long ride, I pump them up to about 105 and 95 psi, respectively. Higher pressures do feel faster on nice tarmac, but I do feel more vibration from the road also and I can feel it starting to wear on me after a couple of hours.


Did try lower pressures (it does feel really plush, too) but going uphill I like a bit more pressure in the rear tire because you've got most of the weight back there. You have variable suspension by simply changing the air pressure, experiment with it.

WhyFi 08-01-19 07:07 AM


Originally Posted by woodway (Post 21054300)
RE: Are wider tires slower? This link is a good discussion backed up by real world testing. FWIW, Bicycle Quarterly is a worthwhile publication.

https://janheine.wordpress.com/2018/...es-are-slower/

That needs to be taken with a very large grain of salt. a) they certainly have a horse in the race, b) much of their "real world" testing is at tame speeds (18.3mph) before aerodynamics really starts to assert itself c) they dismiss objections with the waive of the hand and d) "air doesn't weigh anything" - :twitchy:

DrIsotope 08-01-19 07:23 AM

They were definitely bending the results to their will by testing at 18.3mph. But they sell primarily to tourers and the like, so I don't think they were being disingenuous. Someone setting out to average 22mph all day isn't shopping for 700x35 skinwalls. That guy is too busy shaving grams off of everything in the pursuit of ultimate weight weenieness.

I look at it this way: the rougher the roads get, the wider the tire "needs" to be. Need being very subjective. I might be faster on the skinny tire bike, but not without a cost. I feel like sometimes the roads are trying to pummel me right off the bike-- and trading 1mph for not feeling beat up... generally worth it.

Rides4Beer 08-07-19 07:05 AM


Originally Posted by noodle soup (Post 21051718)
On the Fuji? Let me know how this works out. A friend is thinking about using the same setup on his Transonic.

Tires came in yesterday, they were a little slow getting here from Merlin, but for $85 for two tires and Conti race tubes, I won't complain. Got them mounted up last night, they fit, but I think that's about as big as you can go on the Transonic. Gonna take 'em for a spin today.

https://cimg8.ibsrv.net/gimg/bikefor...7da3cd29b4.jpg

jfranci3 08-07-19 08:18 AM

Make sure you've got 2mm+ of road crud clearance so you don't ruin your paint..

From what I've seen published, a 28mm and 32mm tires can be aero enough with a wide wheel. A 23 or 25mm will generally always be more aero. At about 25mph, the small rolling resistance benefit of the size wider tire traded for the aero benefit of the narrower tire. Fatter tires don't do well at all in crosswinds, as they can't recapture the wind well. The rear tire doesn't matter much for aero. Having the right width of wheel makes a bigger difference than the actual tire size, as going up a size on a narrow aero wheel will cost you 5w (weight average yaw) at 20mph, but only 1w on a wide wheel. At 30mph, you're looking at 20w vs 5w penalties ( https://www.hambini.com/blog/post/bi...ne-is-fastest/ note this test is questionable). On a 30mm wide rim, as 28mm tire is 13% less aero head on than a 23mm tire ( https://store.hedcycling.com/vanquish-gp/ ) - 4watts @ 20mph.

On ideal and good asphalt, at some point you don't see a "wider is faster" benefit in terms of rolling resistance - that's either at +25c or +28c depending on the tire. Tour Int Magazine has a good test rig, showing the GP5K 28c and 25c tires about the same at 80 and 100psi on normal and perfect smooth asphalt (these might actually be effectively the same tire tough). Once the road starts getting more and more texture, the optimal tire pressure drops rapidly (1million psi on a smooth small roller, 110psi glossy Naples FL roads, 90psi smooth dull asphalt, <60psi brick road) with the penalty for the wrong pressure in terms of speed pretty high once you start hitting cracks and patches in the road surface. If you start hitting 1mm+ bumps every 50ft, the picture changes quite a bit.

So.. the whole wider is better thing is true or false depending on where you live and if you're pulling the paceline or in line.

Rides4Beer 08-07-19 09:12 PM

Ran the new 28's at 75/80psi (measured just a hair under 30mm on my 21c rims). No noticeable difference in handling in the wind, but def more comfortable and handled great in the curves. With the crappy roads here, comfort/suspension equals speed.

Badger6 08-07-19 10:51 PM


Originally Posted by Rides4Beer (Post 21051709)
I'm still fairly new to cycling, but I'm finding that bigger tires are in fact faster for me. I'm 185lbs, and on average to crappy roads, comfort = speed. I can def go faster if the tires are soaking up the road instead of bouncing me all over the place.

+1 for me as well...

With some caveats. The inflation psi matters. If you ride in the rain, lower it....and if you can go tubeless, do it.

audiomagnate 08-10-19 09:58 AM


Originally Posted by noodle soup (Post 21050984)
If you never try a new endurance bike, you’ll never know what you’re missing, and always think your bike is good enough.

That sounds like a really good reason NOT to try one LOL, the TOTL Domane is $11,299!

noodle soup 08-10-19 10:51 AM


Originally Posted by audiomagnate (Post 21068991)
That sounds like a really good reason NOT to try one LOL, the TOTL Domane is $11,299!

I don’t know how they(Trek) come up with that price. An SLR frameset is $3200. That leaves about $8000 to complete the build.

(edit)

Dura Ace Di2 - $2200
Frameset - $3300
Enve SES 3.4 AR disc $2500

That comes to $8000

seypat 08-10-19 05:55 PM

When talking about the following, I am only talking about feel.
I have wheelsets with the same rim, with the same brand of tire mounted in 23, 25, 28 and 32. On paved roads not much difference between them all. I can feel some difference between the 23s and 32s, but not much. I feel more differences when comparing different saddles.
On unpaved stuff it is a different story. The skinnier the tire, the more it will dig in and rut the surface. You need wide to float over the surface instead of digging in.

My advice would be to find a budget tire , get some 23s and 32s and do your own test. Maybe find a tire that was upper level a few years ago but is cheap now. I'm sure people can suggest such a tire. Maybe a Conti GP from a few years ago.

WhyFi 08-10-19 06:47 PM


Originally Posted by seypat (Post 21069577)
I have wheelsets with the same rim, with the same brand of tire mounted in 23, 25, 28 and 32. On paved roads not much difference between them all. I can feel some difference between the 23s and 32s, but not much. I feel more differences when comparing different saddles.


At appropriate pressures, I can't imagine not feeling a significant difference unless you're an ultra-lightweight or if you ride on the most pristine roads on the planet. Maybe running super ****ty tires might do it to, but otherwise, I'm at a loss. :foo:

seypat 08-10-19 07:28 PM


Originally Posted by WhyFi (Post 21069651)
At appropriate pressures, I can't imagine not feeling a significant difference unless you're an ultra-lightweight or if you ride on the most pristine roads on the planet. Maybe running super ****ty tires might do it to, but otherwise, I'm at a loss. :foo:

About 200lbs, vintage steel bikes with 32H Shimano 6402 hubs/Sun Ringle ME14A wheelsets plus some other wheelsets. All with Conti GP Classics mounted. If I had to guess, it's because of the saddle. Vintage bikes mean vintage styled or vintage saddles. At least 3 of the bikes have the reissued Selle Turbo. Hard to beat that saddle for me. I can ride it all day long straight out of the packaging. That's probably the reason, or at least a big contributing factor. Now, if I had to choose 1 size to descend on, it would be the 32s. The wider contact patch is a good thing.

noodle soup 08-10-19 07:38 PM


Originally Posted by seypat (Post 21069708)
About 200lbs, vintage steel bikes with 32H Shimano 6402 hubs/Sun Ringle ME14A wheelsets plus some other wheelsets. All with Conti GP Classics mounted. If I had to guess, it's because of the saddle. Vintage bikes mean vintage styled or vintage saddles. At least 3 of the bikes have the reissued Selle Turbo. Hard to beat that saddle for me. I can ride it all day long straight out of the packaging. That's probably the reason, or at least a big contributing factor. Now, if I had to choose 1 size to descend on, it would be the 32s. The wider contact patch is a good thing.

GP Classics aren't a very supple tire. A little softer than a Gatorskin, but not much.

seypat 08-10-19 07:58 PM


Originally Posted by noodle soup (Post 21069724)
GP Classics aren't a very supple tire. A little softer than a Gatorskin, but not much.

But supple enough that I can ride them all day long with no fatigue problems, even the 23s. Also use Fizik performance tape. 3mm I think. Whatever it is, the sum of the parts does it's job.

Racing Dan 08-11-19 01:30 AM


Originally Posted by CliffordK (Post 21053671)
Whew, the last time I did 150 miles on 32mm tires, it just about killed me. :eek: :backpedal:

One thing that should be pointed out is that a quality low rolling resistance 32mm tire is probably close to the rolling resistance of the average 25mm tire.

However, take the commuter tires, touring tires, etc in the 32mm size, and they can be BEASTS. :P

The 32 mm is likely lower rolling resistance at the same pressure. -> You can ride the wider tyre at a lower pressure without a penalty (except weight)

https://www.bicyclerollingresistance...000-comparison

Champ340 08-11-19 02:38 AM

I ride Mavic Aksium rims with 4seasons 25mm tyres. I've been experimenting with 70psi front and rear. 1000km and no punctures. Is this a good idea?

I would ideally want to use 28mm tyres but my 2012 Supersix Evo has no room for this width.

I'm thinking of getting the Hunt Race Aero Wide wheelset. They measure 24mm wide. Does anyone have any experience with these wheels? Will these fit the Evo being a wider rim? I'm guessing being wider they will reduce the tyre height which is my issue with clearance below the brake calipers? I'm hoping they will end up making the tyre more like a 28mm.

seypat 08-11-19 03:59 AM

One thing I forgot to mention:

On harder climbing efforts, I do notice a slight spring like compress release, compress release type of flex feeling with the 32s. Similar to a crew/scull boat lurching forward with each stroke. I probably wouldn't go down that road of discussion, though. You get into the beaten to death subject of stiff vs flex/springy on that path.

Seattle Forrest 08-11-19 10:07 AM


Originally Posted by seypat (Post 21069577)
On unpaved stuff it is a different story. The skinnier the tire, the more it will dig in and rut the surface. You need wide to float over the surface instead of digging in.

I always felt like I could ride dirt in a straight line on 23s, but had to slow way down to turn more than a little.

noodle soup 08-11-19 10:19 AM


Originally Posted by Champ340 (Post 21070005)

I'm thinking of getting the Hunt Race Aero Wide wheelset. They measure 24mm wide. Does anyone have any experience with these wheels?

I've read some bad things about their hubs on another forum( a forum for weight weenies), but have no personal experience with them.


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