I have a 2010 Specialized Sirrus Sport with about 1,500 miles on it and the tires are starting to look worn. I use it exclusively on pavement and am thinking about going with a road-style tire. Currently I have 700x28s and am considering replacing them with 700x23s.

From what I can understand, the pro is less rolling resistance and the con is reduced comfort.

So my questions are, what am I overlooking, and what tires would you recommend?

Stay with 28's, more comfort, better for bad road conditons.
I use these.

https://www.jensonusa.com/store/produ...Road+Tire.aspx

Which tyre is faster depends on your average speed.
Is your average speed around 20 mph -> go for 23's.
Is your average speed around 15 mph -> stick with 28's.
Is your average speed around 10 mph -> go for 35's.

A 23 will not make you faster if you do not go fast enough and it will be less comfortable and less grippy in turns.

G'day mate Ive had a good run using 23mm schwalbe ultremo R1 tyres with a 23mm internal width rim for weekend rides on good roads and dirt pathways, this is not recomended though because for this width rim I should use a 28mm tyre that I do use for riding to work.
Thats because I can only use roads on the way to work with loads of rubbish such a glass shards even nuts bolts screws sharp stones basically everything, for this I use vittoria randonner 28c tyres these are pretty much bomb proof and roll really fast.
I can tell the differance between the two in handling and speed but its very minimal. 23s look killer though.

Thanks for the responses, guys. I live in a hilly area so my speed varies from 5mph up steep grades to 40mph coming down them. My average on flats, when I can find them, is around 18. Road quality is very good but I'm starting to do some event rides where it will probably be more variable.

What I think I'm hearing is that the difference is actually really minimal and it probably makes more sense to stick with 28s.

I could see wearing out a high performance "race" tire in 1500 miles or less, but that sounds like unreasonably little mileage from an "urban" tire. Of course, I don't know what exact tires you have (specs show your bike should have come stock w/All-Condition Sports in 32mm), your weight or the type of riding you do. Sometimes, newer riders (you?? - I don't know) react prematurely to tire wear. A bike tire can typically be ridden until the tread is very squared off, the casing begins to show through the outer rubber tread, and/or you're getting recurring flats. But, if you think the tires are that worn or you simply want something new, then replace them if you wish.

Narrower tires will require higher PSI and will wear a bit faster than wider tires of similar construction. Narrower tires are also more subject to pinch flats and offer less protection to the rim. About the only benefit for everyday recreational riders averaging mere mortal speeds is less rotating weight, something that might be noticeable on long climbs. If you're after less rolling resistance without giving up the advantages of a wider tire, look for a tire with a more supple casing and sidewall.

I have some All Condition 700 x 25 on my Sirrus. They seem plenty fast for me, plus they have some puncture resistance...

But if you really want to know the pluses and minuses of tires, you'll want to review the Schwalbe line. Their web site list the Speed, Grip, Protection and Durability for all their tires... https://www.schwalbetires.com/

And at first blush, maybe it's the Kojak you want... https://www.schwalbetires.com/bike_ti...ad_tires/kojak

Mikey

28s are pretty narrow. What tires have you been using? How did you like them? Are you planning on replacing with the same or a different one?

I have Specialized All Condition 700x28c, which is what it came with. This is my first bicycle in about 20 years so I have no basis of comparison; I've no idea if I like them or not. I run them at about 90psi and have only had one flat when I picked up a nail.

I'm considering desertdork's post above, he's got a point about possibly misjudging wear as I still fall into the newb category. The rear tire is just about worn smooth on the contact patch but not showing the casing or anything like that. Hmm.

If the tread is gone, you might replace the tire. I'm running a rear tire that is down to the casing in a few spots, but most people don't wait that long. It's risky.If you want to reduce your consumption which I highly recommend, instead of changing both tires, you can move the front tire to the back and put a new tire on the front. That's what I do.

I have 28's on my bike. Last year I replaced them with continental goatskins and accidentally grabbed a one 28 and one 25. I could barley get the 25 on the rim and pinched the tube doing it. I was in my garage and I'm not sure what I would have been able to do if I got a flat on the road. I would stay with 28's if that's what you bike came with.

Thanks for all the tips. On my ride today I caught a flat when I picked up a self-tapping bolt. No tire would have stopped it, but I'm using it as an excuse to replace the tires anyway.

I do think I will stick with the 28s, though.

Bike tires are a lot like car tires. There are tires engineered to preform and tires that are engineered to be affordable. A cheap tire will deliver little else but a low price. Even durability in a cheap tire is traded off against reduced grip and braking performance.

But it depends what works for you. Schwalbe designs tires that combine technologies that deliver low rolling resistance, puncture protection, excellent wet and dry weather grip as well as outstanding durability. On the other hand they cost 3 to 4 times as much as some cheaper tires.

The reduction in rolling resistance comes from two sources: a high thread count per inch tire carcass and high inflation pressures. The former is neutral to positive for comfort, the latter is detrimental to comfort but under your control. Continental Gatorskins and Grand Prix 4 Season tires as well as Vittoria Randonneur Hyper and Pro tires can be had in widths of 28 mm or higher, with high tpi carcasses, and can be inflated to reasonably high pressures. Some of their road tire models may offer a 28 mm width too. Other brands may have similar models if you check, those are the two I am most familiar with except for Hutchinson who don't seem to believe that people who want wide tires also want efficient tires, unfortunately. There is a third component to rolling resistance, namely width. However, contrary to common belief wide tires have less rolling resistance than narrow tires when width alone is varied. The most efficient tires are developed for road racing though and at road racing speed the aerodynamic performance is critical too. So tire makers tend to make their road racing tires with the most efficient casings and pressures but in narrow widths. Wider tires are seen as less sensitive to efficiency in the consumer's minds so they tend to get second, third, fourth, ... rate materials and construction techniques in the mistaken belief that we aren't interested in high efficiency tires. Actually at the speeds many of us cruise at the tire rolling resistance is a higher penalty for us than it is for the super fit, Mach one, road racer. Other things contribute to tire casing efficiency of course and some of the very desirable ones like puncture resistance can have a detrimental effect on efficiency.

So, you can find some quite excellent (though probably not quite best in the world class) 28 mm tires. Tires of that width offer a reasonable level of performance on surfaces that hybrid riders expect to tackle and road riders avoid if at all possible. A high pressure wide tire can be run at lower pressures for comfort when conditions demand without becoming an invitation to pinch flats and 28 mm is wide enough to offer some of the wide tire comfort advantage. Even wider tires are available with fairly efficient construction these days but 28 mm is about the widest width that is offered with near elite road tire performance by the three brands I have studied the most. I am planning to try a century this year and I am currently thinking I will go with 28's for that event. My speed won't be high enough to benefit aerodynamically from narrower tires and the best 28's will roll as well as all but the very, very best 25's and 23's. Whatever difference there is may win a race, it is unlikely to prevent me from completing the event or make me noticeably less tired at the end.

Time to start training in earnest though....

Ken

A lot of research has gone into discovering whether a skinny high psi tyre is actually any faster than a wider tyre of the same composition and most people are surprised, (and a few are still in denial), to find that wider tyres actually roll out better and much of the speed you get out of skinny high psi tyres is a misperception.

The only advantage a 23 has over a comparable 28 is a small edge in aerodynamics and the slightly wider and higher volume tyre will offer an improved ride and better handling.

The construction of a tyre has more to do with how fast it is and how well a tyre rolls is based partly on the stiffness / deformation qualities of the sidewalls and how well they pass over small obstacles... too much psi will reduce a tyres ability to absorb the small imperfections and debris we ride over and can have a negative effect on handling and performance.

When you set your air pressure your tyres should deform / compress by about 10% of their depth when you are on the bike, heavier riders will need more psi while lighter riders should use lower pressures to get the same compression.

So with all that being said... I have been riding a set of 700:23 Continental Ultra Sport Kevlar tyres for well over a season on my fixed gear road bike and despite their narrow width and fact I do run them at 100 psi (120 psi is max) they have an awesome ride quality and are exceptionally fast.

I usually run 25-28's on my geared road bike and my hybrid runs some 700/35 Schwalbe cross tyres that I find to roll out better than Marathons as they are lighter and have some decent puncture protection... my last set of these went 8000 km without a flat and are still in daily use.

I wound up going with Conti Ultra Gator Skin 700x28s and have put about 50 miles on them since I put them on. They feel faster than the Specialized All Condition 28's they replaced, but also less comfortable. I assume both are because I'm running them at higher pressure, about 100 in front and 105 in back (max is 116 IIRC). I'm going to drop them down about 5psi each and see how that feels (I ran the old tires at 90/95). So far I'm happy with them, time will tell if I stay that way.

Once again, thanks for all the advice!