GFish

My entry level steel bike has 1250 miles on it and the inexpensive tires are showing some wear, so I've started researching replacement tires. But, I have a question concerning tire width.

Is there any real difference between a 25 or 28 concerning rolling resistance and comfort?

My current tires are 700x25 and I ride for fun and overall fitness, no racing or serious speed. I'd like a smooth rolling tire for all around riding, from; short intervals, climbing, leisure group rides and even a century or two. Also, I may ride the bike in wet weather too.

My son is recommending a 700x28, he said the tire is more comfortable then a 23 or 25 and I won't notice the extra width. Which I why I'm asking here since the 25's have been OK, but this if my first road bike so I have no experience.

So what do you prefer and if you have a tire recommendation, that would help too.

Thanks

I_like_cereal

A question that is oft debated.

23s at high pressure tend to bounce which means more power ends up in the air. 25s seem to have a slightly wider tire patch on the ground and at lower pressures tend to bounce less. The rolling resistance seems to be less with 25s.

Some believe that 25s are the best as far as rolling resistance. 28s are said to be wider with more contact patch and therefor more resistance.

Personally, my 25 works great on the rear and my 23 works great on the front. I cannot run a 28, but I would not use one.

Its all personal preference. Conti All seasons, or Vittorias.

Good luck.

Don in Austin

I run 28s. The information you didn't give was how rough are the streets you usually ride. The poorer the surface the wider the tire you need. If the roads are really crappy you might even be best off on 32s. If your roads are less than ideal I think you will notice the increased comfort of 28s far more than you will notice a possible miniscule drop in speed. Unless you are really heavy, you need not and should not max out the pressures.

Don in Austin

FrenchFit 

I run 28mm on a couple bikes, but they tend to be heavy and slow - but plush. Good for loaded rides. My strong preference is 25mm. If you are riding on chipseal or rotted road, then 28mm.

scroca

I'd look for the characteristics you want in a tire, such as cost, flat resistance, durability, rolling resistance, etc and get what seems to fit the bill.

DnvrFox

I must be a hard a$$.

I notice no difference in "comfort" between any of the 700's, nor between any of the 700's and the 26" slicks on my mtn bike, nor on the mtn bike between having the front suspension locked in our out, nor between any of them and the 16's and 20's on my bent.

They all ride the same for me.

I think it is all psychological. and in the expectations of the rider.

However, I do find the 700x25's to be better in light sand/gravel than the 23's, 20's or 19's. Now that is NOT psychological.

cehowardGS

I run 23s, with close to max pressures. All my riding is on smooth roads/surfaces, and I hit the scales at 134 lbs. In fact, I got 23s on all 8 of my bikes. Works for me..

Barrettscv 

+1

I've used both 25 and 28 sizes and I will also run one size larger in the rear. 28s are better if speed is not an issue. The larger tires are slightly more dependable of poor surfaces. I'll run slightly lower air pressures and enjoy a slightly smoother ride as a result.

NOS88

If you've been happy with the 25s why not stay with them? Reducing the pressure in each tire by 5 lbs will make a noticeable difference in comfort.

leob1

Stick with the 25's.

BluesDawg

If 28s will fit your bike, why not give them a try? If you decide you liked the 25s better you can change back next time you need tires.

I have ridden many sets of 28s and 25s and 23s. The wider tires allow lower pressure without pinch flats which gives a bit softer ride. A turn down a dirt road becomes much less of a challenge. But the wider tires are a little heavier and maybe a little more road resistance at the lower pressure.

CraigB

Keep in mind that regardless of the perceived benefits of any particular tire size, there can be a pretty large degree of variation in different manufacturers' tires of any given size. Some brands seem to run large, and some seem to run small, and some aren't even consistent across their own model lines. I've seen 25s that are as small as 23s and some that look more like 28s. Go ahead and choose based on the numbers if that's the only criterion available to you, but don't be surprised if, once mounted, they look and perform like a different animal than you expected.

billydonn

28s will not fit on some road bikes, so be aware of that. Also a 28 rear 25 front combo may be a little more difficult (not impossible) to come up with since many manufacturers do not make 28 to match a smaller tire.

jimmuller 

I've got two old steel bikes. The lighter one has 25's, the heavier one which I've been using for commuting has 28's. When I ride the good bike I pump the tires to their max, 110psi. I pump the commuter to their max 105psi every so often but they drift down until I pump them up again a few days or a week later.

On the commuter I can feel the difference in how smooth the ride is when I pump them up. I think they also have less rolling resistance when I pump them up. The 25's on the lighter bike ride harder and seem to roll more easily. Part of the ride difference may be the geometry of the frame, not the tires; it has longer chainstays and I'm sure shallower angles.

But the difference between the 25's and 28's when they are pumped up is pretty subtle. If you rode blindfolded you probably could not tell the difference (but you might run into something).

tsl

I run 25mm on my two roadies. It's the largest that will fit in their brakes. I run the same model in 28mm on my commuter. I have the inflation pressure adjusted appropriately to each size. Any difference in ride and rolling resistance I can detect between the two is probably placebo effect.

GFish

Thanks everyone for your quick response, very much appreciated.

I'm getting the impression from the replies that it doesn't really matter which tire size in the grand scheme of things. Even if the tire is 140 grams heavier in 28mm versus 25mm, my biggest problem is I'm still heavy at 190lbs and the bike is 24lbs.

The tire I'm considering is the Continental GatorHardshell for the resistance to flats and durability. From the Conti site, the Hardshell is a newer version of the Ultra with improved performance. But I'm still open to other recommendations.

A for roads, a lot of them are chipseal and some are rather poor. And for some reason, both counties in this area are covering more rural asphalt roads in chipseal every year. Don't suppose there is a magical tire that makes chipseal feel like smooth asphalt, could be worth some money if there was.

Since I haven't had any problems with a 25mm and haven't read anything compelling for the 28mm, I may just stick with the 25mm. Just one more thing, as I keep working on improving my fitness, I'm also trying to improve my overall speed. Sometimes I ride with stronger and faster riders and my goal is to work up to their level. Perhaps I just answered my own question and this will be the most compelling reason to stay with a 25mm.

Again, thanks everyone.

stapfam

Riding in the wet- With narrow tyres you will not need a tread on the tyre. That goes for 28's aswell as the good brand slick tyres are made with a rubber that is "sticky" on the road. Saying that I know my Michelin PR3's are stickier than the Michelin Lithions in the dry- let alone wet. On top of that- the amount of rubber with slicks on the road is minimal so a tread would not be that effective unless you are riding down mountains at high speed with the bike leaned over for the hairpin bends in the wet. But as mentioned- some rubber is stickier than others.

Chipseal poses its own problems with regard to comfort. Run a 23 at 120psi over that stuff and you will be shaken up a bit wheras a 28 at 90psi would absorb some of the vibration. With regard to drag- and I know some will disagree but a 23 at 120 and a 28 at 120 will be about the same amount of rubber- and hence drag- in contact with the road. Only thing is you can run a 28 at lower pressure for the comfort factor.

I had a problem with my first Road bike and that was the tyres. Kenda 26's and rolling speed downhill was not good. There was drag-even at 130psi. I got New handbuilt wheels and Michelin PR2's in 23 and rolling speed went way up. On a particular hill from 30mph to 37. Some of theat may have been the better wheels but I doubt that it was much. Still have those 26 tyres and I put them on my son-in-laws bike. When he wore them out I put on some 23's and he noticed the difference straight away. So Quality tyres do work on the speed side- if not the long life.

BigBlueToe

I rode 28's for years. Then, when I bought my new tourer I put 32's on it. When I built up a road bike for my wife, I went with 23's, because she wanted something fast (?) When I built up a road bike for myself I put 25's on it. I wanted something fast too, but I weigh 200 lbs.

I don't have any objective data to share, other than we are happy with the tire choices on all our bikes.

On my road bike I went with blue tread, with a black stripe down the middle. They look good with the frame's blue paint. On my wife's black and red road bike (her favorite color combination) I mounted tires with red treads and black stripes down the middle. She thinks they look cool.

Don't discount looks as part of the equation.

Be happy.

late

Try a 28.

If you don't like them, you can change.

I used to ride 28s, then the roads around here get a LOT worse and I ride 32 now.
That's a real 32c.

A Conti 28c is usually going to be closer to 26c.
They make a performance tire in that size, looks really nice to me.
https://www.biketiresdirect.com/produ...n-with-vectran

Then there's the Rivendell Ruffy Tuffy at 27c. I used that for years.


Another good 28c is the Vittoria Randonneur. Very durable, and feels quicker than the Ruffy Tuffy.

jimmuller 

No disagreeing, but a qualification. You are right about the contact patch size, since it will become whatever necessary so that the area times the pressure equals the weight it must carry. But the shape of the contact patch will be different, narrower and longer for the skinnier tire. Hence the amount and type of sidewall and tread deflection will be different. Tire deflection of the stiff components like sidewall and tread is the greatest cause of rolling resistance per se.

In practice one can't easily project how this affects the ride or rolling resistance because there are so many other variables. For example, a small deflection from a bump will be a greater fraction of the total tire volume for the skinnier tire, hence it should build up pressure faster during a bump but deform less. On the other hand, it will exert more vertical force on the bike during that bump, theoretically slowing it and making the rider uncomfortable. The skinnier tire will be lighter and will offer less wind drag at speed. In theory its smaller size allows it to carry a higher pressure (skinnier tires are usually labeled with a higher max) so the contact patch can be smaller, but you actually have to pump it (or them) to that max for that to matter at all.

Hermes

There is some data on tire performance and aerodynamics that matter and are measurable. For example, the Zipp engineer calculated there was a 6 watt savings going from a 25 mm to a 23 mm tire.

Rolling resistance tends to be lower with a 25 v 23 but that is a big depends which is the pressure used and the surface. If the tire is "skipping" on the surface then the performance decreases. I like to run my 23s at as low a pressure as possible. When racing on wet roads, we reduce the pressure to 90 psig.

Where weight is on a bicycle matters. If the weight is on the frame and it is not spinning the 1 pound = 1 pound. If one adds weight to the perimeter of the wheel then the equation changes. As a rule of thumb, I use 1 pound of weight on the perimeter of the wheel = 2 pounds to the weight of the bike. So adding 150 grams per wheel by my equation is approximately 600 gms.

Adding weight to the bike and increasing the profile in the wind just adds overhead. For recreational riders where your power is limited, it has a larger affect on a percentage basis. For guys like me, more weight or drag, does not affect our performance as much on a percentage basis since we make more power. However, we chase performance because we can lose by .05 seconds so details matter.

The silver bullet to increasing performance is lose weigh off your body. If you lost 20 pounds, you were be a substantially better cyclist and feel a lot better, if that is your goal. The next best thing is to train harder and more consistently. Finally, the bike and equipment matter just not as much.

GFish

Yes, completely agree with this. That's why I purchased a heavier beginners bike since the equipment wasn't the limiting factor, it was and is my overall weight. I've lost 22 pounds in the last 3 months without dieting and plan to lose another 20 pounds. So I may have to stop eating pie and ice cream.

I appreciate the information on how weight to the perimeter of the wheel affects overall bike weight. This must be why people spend so much on quality wheels and tires. I have a long way to go before this becomes important to me.

OK, so I shouldn't forget how the tire looks, I can relate to this. After all, there is a reason why we choose the bikes we ride. And stapfamm, thanks for the information on wet roads and slick tires.

Thanks again everyone.

XR2

I'm a big fat guy. I run 32's at 84f/90r. I've even left the house without pumping them up and lived to tell about it. I just ride because I enjoy it and that's it.

Wogster

There are several aspects to buying tires, fit, price, speed and road conditions. Fit, some bicycles are made for narrower tires, if a 28mm will not fit, then the question is moot. Price, the tire you want may not be available in that size at a reasonable price point -- I've seen where different sizes of the same tire, were different prices. A narrower tire takes a higher pressure, that typically means a lower rolling resistance or slightly faster ride on smooth pavement. Wider tires typically take lower pressures which means the tires absorb more of the unevenness on less ideal pavement or unpaved roads.

AzTallRider

The Conti GP4000S "Black Chili" is extremely popular. In my experience, it is as resistant to flats as the Gatorskin, and performs much better. Many people use them for both training (which needs flat resistance and longevity) and racing, where weight, a smooth ride and grip are paramount. The tire compound is hard enough to wear pretty well. That generally also means it will not grip, as grip requires a softer compound, which will wear out quickly. The GP 4000S overcomes this by adding "Activated Silica", which improves grip. It's a great all around tire.