[trek5900cyclist]

I run 23 right now but they are soon to be replaced with 20s. Some say this is for the better and that I will have less rolling resistance. Yet others say it wont help much and will actually take away from aerodynamics. The way my tires sides stick out about 2 mm from the rim I figure 20s will help aero. What do u guys think?

 

[filtersweep]

Your wheel is the same width, isn't it? 2mm of tire really won't change much of your aero profile- an aero helmet would give you more of an advantage than the tire. A 20 may allow you to run with a higher pressure, but even that ends up being rather dubious. I've run with a 19 before, and found the handling to be noticeably less certain. Maybe if you were in a very controlled environment, like a track you might see some benefits, but I believe the analytic cycling website has been notably quiet on this topic, leading me to believe it is insignificant.

Have you checked this old link?

http://www.slowtwitch.com/mainheadings/techctr/rolling.html#Anchor-49575

 

[AJS]

For road-specific tires, I don't use smaller than 23c, because I'm a fat-ass (200#). Less aero, but better handling than skinnier sizes.

 

[biknben]

A mix of widths...

I commute on 28s

I train on 25s

I race on 23s

I notice the wider tire a more comfortable ride moreso than any improvement in aero or rolling resistance.

 

[Hereford Flyer]

Stick with 23mm.
23 will give you less rolling resistance, better handling, and a smoother ride. Even the majority of indoor track riders prefer 22-23mm for the above reasons and they ride on super smooth surfaces. Any "aero advantage" will be out weighed by the above mentioned advantages.
Super thin used to be the thinking back in the 1980's. Even I fell for it. Used to have a set of 18mm wolber rims with tiny 18mm tubs on (fatastic looking wheels) - used to run them at 160psi. Boy was that a hard ride! They used to make a great noise though.

 

[Cory]

Am I the only man in America on 32s?

I'm a Clydesdale, and more so now than I will be in June...but I haven't bought anything smaller than 28mm tires in years, and do most of my riding on 32s or 35s. Granted, I'm not racing, but there's NO difference in times or perceived exertion on my usual courses between 25mm tires (skinniest I could stand to look at) and 32s, and the 32s give much more secure grip and better comfort, plus fewer worries about potholes. I commute on 35mm Pasela TGs at 75-80 psi, and they make a difference of only 30-90 SECONDS on an 11-mile trip. What I had for breakfast matters more than that.
At least for general, all-around riding, try the biggest tires you can squeeze in there, probably 28mm on most modern bikes. You might be surprised.

 

[supercrank]

stay with 23

I run 23 right now but they are soon to be replaced with 20s. Some say this is for the better and that I will have less rolling resistance. Yet others say it wont help much and will actually take away from aerodynamics. The way my tires sides stick out about 2 mm from the rim I figure 20s will help aero. What do u guys think?

From what I remember, for two tires (one 23mm, one 20mm) with the same contact patch area, the 23mm tire will actually have less rolling resistance due to a lesser degree of tread deformation. Aerodynamics are another matter, and I don't know if the result of tire width change is easily predictable (or even all that significant). FWIW, I'm 5'8" 155 lbs and run 23mm tires.

 

[JimP]

You forgot 22mm - Conti Sprinter and 21.5 - Vittoria Corsa

 

[PT]

You're not the only one...

...do most of my riding on 32s or 35s..At least for general, all-around riding, try the biggest tires you can squeeze in there, probably 28mm on most modern bikes. You might be surprised.

I do 70% of my miles on 32c tires, notably the Panaracer Pasela model. The other 30% are ridden on authentic 35c cross tires. I run the 32c tires at around 95 PSI and they go like crazy -- I did a 170 mile day on them last year, some of it in the mountains, and averaged 17 mph. I don't notice them being slower and sometimes I think that going down the road on the flats they might actually be faster than a good 23c tire. One reason I use 32c is that almost any ride I do involves substantial dirt road sections and I don't want the hassle and expense of flats and rim damage from hitting the odd rock. I have to admit I haven't used them in a race, but I do fast group rides with those tires and only have problems in the group sprint for the city limit sign.

 

[PdxMark]

I weigh 165 pounds. I ride 23s on my road bikes and 26s on my commuter. I might go up to 28s on the rando bike to try them out.

 

[filtersweep]

You forgot 22mm - Conti Sprinter and 21.5 - Vittoria Corsa

I have a bunch of 22s- Vitorrias and Veloflex- is there really any difference between them and 23s?

 

[G-dub]

Conti Attack - Force

I'm a 210 #'er and I ride the Conti Attack - Force. You get the best of both worlds with these...a 23 rear tire that is very comfortable with ultra high thread count....and a 22 front tire. I think they weigh in at about 400 grams. I dont have alot of miles on these things yet but they are super light and have a nice roll. A little pricey, but all us gram weenies love all that less spun weight.

 

[Thorman]

My first road bike came with 23's and I sliced one up shortly after buying it and the small shop I went to get new tires from only had a set of 20's and that's what I've been riding ever since. I don't think there's much difference between 20's and 23's. I just like the leaner look of a 20 so that's what I buy.

 

[GeekRoadie]

23's and 25's for me

I weigh less than 150 and use 23's on my bikes except my commuter. It's really not a fair comparison when looking at 23 vs 25 vs 28 vs 32 vs .... There aren't too many high performance road tires wider than 23. That said, I'd never give up my cheapo 25's when commuting, esp. when riding through crappy roads. I'd ride wider ones if I had better clearance.

 

[Coolhand]

23 mm on my main road ride, 25 mm road tires on my cross bike.

 

[froze]

I no longer race, but I do ride to commute and for fitness, thus I'm always riding on city streets with all their potholes, cracks, grooves, trash, whatever and I'm not a heavy weight (163lbs). I ride on nothing less than 25mm and not more than 28mm (that's the largest I can put on my roadie) tires because these larger sizes have less of a tendancy to follow grooves or cracks making for some wild moments, they stop quicker, have a softer ride and last longer.

 

[FrankDL]

Sizes, sizes, sizes.

I run 23 right now but they are soon to be replaced with 20s. Some say this is for the better and that I will have less rolling resistance. Yet others say it wont help much and will actually take away from aerodynamics. The way my tires sides stick out about 2 mm from the rim I figure 20s will help aero. What do u guys think?

This site has some very good information on tire sizing. It dispeled many a myth about tires that I held to be true for years.

http://www.sheldonbrown.com/tires.html#mixing

Best,
Frank

 

[tube_ee]

wider tire = lower rolling resistance

I run 23 right now but they are soon to be replaced with 20s. Some say this is for the better and that I will have less rolling resistance. Yet others say it wont help much and will actually take away from aerodynamics. The way my tires sides stick out about 2 mm from the rim I figure 20s will help aero. What do u guys think?

At least with similar tires run at the same pressure. It's counter-intuitive, but this was demonstrated by Jobst Brandt in the early '80s, and it also holds up in the theoretical sense. Here's how it works:

A tire's contact patch is related only to the pressure in the tire and the load. The contact patch is a rectangle. The area of the rectangle is equal to the load divided by the pressure. If there is 100 lbs of load on a tire with 100 psi of pressure, it will have a 1 square inch contact patch, regardless of the dimensions of the tire.

Area = length * width

For a tire, width is fixed, so the length of the contact patch is what varies. A wider tire will have a wider, shorter contact patch, a narrow tire will have a longer, skinnier contact patch.

The primary contributor to rolling resistance is flexing and deformation in the tire casing. A narrower tire will have to flex over a greater length to acheive a given contact patch area, and will therefore have higher rolling resistance.

--Shannon

 

[Reynolds531]

Hey, what about 27 x 1 1/4

Tough to find good tires though. On ohter bikes, I'm with Cory with 28 - 32 mm.

 

[tube_ee]

There are a few

Tough to find good tires though. On ohter bikes, I'm with Cory with 28 - 32 mm.

Conti Top Touring, Panaracer Pasela, maybe one or two others. Check Harris Cyclery, they've got a ton of tires for older bikes.

--Shannon