aeonderdonk

Preferences anyone?

I'm currently running Conti Gatorskins 700x23 which are near the end of their life and someone on craigslist has a set of 700x25 they'll sell me for $50 (saving ~$15). Anyone notice a big difference between the two?

Bioluminescence

I ride x26 because of some mild dirt trails around here.

Psimet2001 

Depends on your weight. In general there are some studies that show lower rolling resistance with 25's given the right inflation for the rider. You should notice a more comfortable ride as you will be able to ride at a lower pressure with the larger volume tire.

My take? There isn't much of a difference. If you're over 200 then get the 25's if they have them. As a dealer I find that all this talk of 25's has caught suppliers out and there simply aren't any in stock anywhere...so....sure...get them. Especially if they save you money.

i guess...what downside are you worried about? Someone might tease you about your "fat" tires?

aeonderdonk

I'm 220. My thought is that they're fatter and I'll be slower? But probably negligibly so.

pgjackson

I weigh 175lbs. I went with the 23's just because I couldn't find Rubino Pro Slicks in 25's. Plus, the 23's are much easier to get on and off the bike. Even with the brake released, the old 25's would get stuck between the brake pads. Not a big deal, but it was a PITA sometimes when trying to get the rear wheel back on and the tire keeps getting stuck between the brake pads. But to answer your question, I don't notice much difference between the two sizes while riding.

pgjackson

We are talking about a 2mm difference. You want to worry about something tire-related, ask about treaded vs. slick.

shuffles

To me, 25 vs. 23 is a huge difference in ride with the GP4000 tires. I'm 210, but the 25s just ride so much nicer and give a lot more confidence in cornering. The 23s were a much rougher ride. Of course, I was running the 23s at about 115, and I run the 25s right at 100.

Gege-Bubu

I am 145. Last year I had x25. This year I have x23.
No difference. At least I don't feel it.

cyclezen

+1

if you were goin to 28 or 32, yes the greater mass might make em seem a bit slower. But 23 to 25...
more diff. between tire brands and models... lotsa studies, all show the 25 being equal to or faster than smaller profile for regular road ridin.

only caveat - some bikes just won;t take a 25mm rear - I know, seems unlikely...but
my Marin argenta (alu) is so tight at the chainstays that a 25mm conti will not work (so most any 25 prolly won;t either), when I get out of the saddle I could feel the rub at the stays - and the paint got rubbed off... all with a very true, reasonably stiff wheel under a 165 lb'r. I have to use 23s on that bike.
happens to be the bike I use for weekly hillclimb rides - so out of the saddle and pushin a lot...

Psimet2001 

At 220 - get 25's. Are they slower? No. Like I said some reports are showing conclusions that in some cases they are in fact faster than 23's. To give you an idea f this trend - like I said almost all suppliers seem to go out of stock now on 25's in clinchers and 23's in tubulars. They can't seem to even GIVE away the 21's in tubulars seemingly.

There is more than just a 2mm difference - you have a increase in air volume for that additional "2mm" of nominal width. As for tread/no tread- red herring. Tread does nothing on bicycle tires in this size range. The contact patch is so small and the forces to high that treads are simply ineffective. They are there because of tradition and looks and to make consumers who wonder about treads feel like they are going to have more traction.

Someone always posts the equations, but in general to get a bicycle to hydroplane it would have to be traveling at something like 300-500mph.

With 25's at lower air pressure the tire conforms well to the terrain and "scrubs" less speed caused by having to ride higher pressures in smaller tires (Same force in a smaller contact patch).

Rider weight affects all of this the most. In testing it appears that as we have all gotten fatter we are better served with 25's.

25's on a 145 pound cyclist riding on fairly smooth roads is less effective than riding 23's....unless you want to start talking about aerodynamics.....*oh geez*

Psimet2001 

Yup. I have a set of 25's Michelin Pro Race 2's that are so flippin big that I have yet to really be able to ride them on anything other than my cross bike. So much so that I locked my road bike up solid during one of our "epic" spring road races over gravel as the muddy/sand/gravel mix just built up between the tire and frame so much that it stopped everything. Cleaning it up it looked like the brake bridge had just been sandblasted back to bare metal.

urbanknight

Since road tires have a round cross section, the contact area is pretty much the same as long as the tire pressure is the same. There is even an argument that the wider tires will have less rolling resistance because the tire will deform less in order to get the same surface area. I have a link to it on my bookmarks at home.

Anyway, I switched to 25s last year and can't tell the difference (running the same psi) although it's nice to know I could lower the pressure on rougher roads with less risk of pinch flats.

Kelrod

I notice a difference, I ride the gp4000s in 23 and went to 25 on my CAAD. The difference comes from the lower psi. I went from running 110 to 95. I weigh in at 175.

Seattle Forrest

Gatorskins, or Gatorskin Ultras? $65 is a lot of money for a mediocre tire if they're not ultras.

Could you elaborate on the cornering feeling safer with wider tires?

AltheCyclist

Agreed, 2mm is about this big: _

The tire pressure and treading will have more impact. I take it the CL ad is for new ones? I wouldn't buy used tires or even new ones that have been sitting for years. Spend the 15$ and get the ones you prefer, don't base just on size.

lunchbox1972

I'm 230 and I just started running Ultra Gatorskins in the 25 size a few months ago.. I've put about 1000 miles on them and I love them. I don't ever plan on going back to a 23, ever. I run 100 psi and they roll so much nicer than the smaller tire.

The Gatorskin 25 is a huge tire though, judging by other 25's, I'd say it's larger and so do my measurements. I don't remember the specifics, but I measure a buddy's Armadillo, and the Forte Strada-K's, the 25 was larger than the 28 Forte and the 25 Armadillo..

I think I feel better in the corners because I am just not getting jostled by the road so much..

That's my $.02, YMMV..

Clipped_in

I switched from Vittoria Rubino Pro Slick 23's to 25's about 400 miles (~2 weeks) ago . I'm 6'-3" 195# and for me there is an improved ride quality and more stable feel. I like 'em.

pgjackson

Where did you find 25's? I can only find 23's locally.

GP

I switched from Rubino Pro 23s to the same in 25. The lower pressure makes a noticable difference in the ride.

Clipped_in

Performance has them for a great price right now.

Elvo

You can get them for $27 shipped here after code VELONEWS10

https://www.probikekit.com/us/tyres-t...road-tyre.html

handz98

Switched from 23mm to 25mm this year (GP 4000). Made a huge difference in ride comfort for me especially this time of year when all of our chipseal roads get a fresh coat of gravel. Less vibration and more stability. 157# and running 96# rear and 86# front.

escarpment

i ride a 23 bontrager race slick in front and a 25 serfas with tread on the sides in the back, but i only weigh 140 and i keep the pressure at 110 give or take, I would ride my tubulars if I could but Chicago roads eat them for breakfest, I like the slick front cause i feel I have better traction and control when I turn. And the tread in the back so I dont skid out when I break at high speeds. But I have heard that 25 or even higher with a less then recomended psi do have less rolling resistance, Theoretically on flat ground 23's or 21's with high pressure have a lower RR, but in reality a road is not perfectly flat or even remotely flat and the hard wheel vibrates and bounces off imperfections in the ground, disrupting speed. A bigger tire with the right PSI will absorb these bumps and keep you going straight.

Haku

I run GP4000s 25c on my training rides and race GP4000s 23c. I feel that the 25c takes the high pitch buzz out of the ride. When I race the 23c are just a little more responsive, with that said I would not train long rides on the 23c unless I have no choice. On long rides, 50 or more miles, I have less muscle fatigue with the 25c. The high pitch vibrations that the 25c cuts down on seem to lesson muscle fatigue. When I am racing I am less worried about the fatigue than I am with going fast. This is my observation over the last 10 years or so anyway.

datlas 

Doesn't it make more sense to run 23 on front for maneuverability and 25 on back for comfort/stability?

If I weighed 180+ that's what I would do.

I weigh 140-145 so I just run 23's front and back.