what a difference a few cm makes (tire thread)
 

after several years, I just switched the 23 (cm?) tires on my commuter to 28s! wow, what a difference, feels like I'm riding on air (which actually I am). but a lot less bumpy. I love it! Little changes can make a huge difference sometimes.

You know what they say - once you've had fat, you'll never go back. I am very happy that my road bike can take 700 X 38c tires with fenders. Potholes and railroad tracks are standard road features around here, and the skinny stuff is much more trouble than it is worth.

I'm already wondering if I can fit 32s on there!!

23 cm would be a pretty wide car tire - if these are for a bicycle then you're dealing with widths in mm. Not sure why there's such a tendency to randomly add the 'c' after tire widths these days. Presumably it came from the 700c rim size which has nothing to do with cm - just that there were various width rims: 700a, 700b, 700c, 700d and only the 700c size happened to remain popular. But labeling tire widths with a 'c' as in 23c, 32c, etc. makes no sense.

Thanks for the clarification, Prathmann!

Of my four bikes, the skinniest tire is a 32mm. The widest is a 42mm. I like the comfort.

I ride 1.25" tires, which are about 31mm. I went from a mountain bike to this, and this is the thinnest I have ever ridden. So it feels rougher than what I'm used to.

28? How can you live with such skinny tires? I'm running 700x50 today. :D

whoa.

I've been sold on wider tires for a while now. 26 x 1.5 to 1.75 inches is about the sweet spot for me. I have a racing frame from the mid 80s that I'm coverting to 26 inch just so I can run wider tires. 28s are the fattest that will clear at all. It's a crazy idea, but I like to tinker.

Yeah, the measurements for wheels are kind of nutty. I love the craigslist ads that list a bike with "700 cm" wheels, or the occasional "57 inch" frame.

I know what you mean Rando, I switched from 700 x 23 road tires to 700 x 35 cross tires in the fall and the ride was way more comfortable! I didn't really notice a big decrease in speed either, though it has to be affected slightly.

By the way, nice dog! Beagle? :-)

I like the wider tires too. I wish I could fit soemthing alot wider on my Lemond. I had to buy some new tires for that bike and I swear its much more comfy with some cheap 28c than the 23c that were on there before. Its not like I care that much about speed even though the only reason I ride that bike is for recreation.

On my commuter I don't think I would go with anything less than 26x1.5 unless my commute got alot longer and I think I have 1.75 tires on there now. I like the comfort of the wider tire and feeling that if I encounter gravel patches (I do on occasion) I can navigate them more easily.

yup. Mortie.

Racers use extremely small tires because of their cornering profile (smaller tire = less deflection = fewer wipeouts). It has nothing to do with speed. Wider tires tend to be a bit slower because they have lower pressure limits, but that's a pretty small impact.

That said, I'm just really not convinced on the comfort benefits. I just switched my (hard frame) MTB from a 26x2.125 to a 26x1.75, and am finding the ride much more comfortable. Of course, there's a lot of variables that go into comfort, so it's hard to do a side by side comparison, but I'm just not convinced that size is the main determinant of comfort.

I ride 700 x 28 on my commuter. Its the perfect balance between speed and comfort, it's just right for me.

And footprint - wider tires have a wider contact patch so increased rolling resistance... but yeah, for commuting tire width effects speed a lot less than most would expect.

I had the same experience with converting an old hard frame MTB from 26x2.125 to 26x1.75, and found the bike was more comfortable with the 26x1.75 tires as well. After having tried a few different sizes of 26" tires, I find that a good 26x1.75 gives me my favorite balance of performance and comfort. The brand and quality of tire seems to have a bigger impact on speed than size alone. I recently put 26x1.75 Conti Contact tires on my commuter, and found that it is significantly better in both comfort and speed than it was with the 26x1.75 Innova tires it had before. I moved the Innova tires to the mountain bike in place of its 26x2.125 knobbies, and found its ride to be improved as well. I will eventually put Conti Contacts or Serfas Drifters on the mountain bike as well.

Strictly speaking, this isn't true. It's because of the lower pressure, not the extra width, that the wider tires will have increased rolling resistance.

I wish I could know what you guys are talking about. 23C is as big as my bike gets without losing my fenders. And frankly, the day I give up fenders on a commuter is the day you pry said fenders from my cold, dead bike.

I can live with the smaller tires around these parts though. As far as bicycles go, it's like driving a "Porsche" to work rather than the "Suburban" I had before.

I've ridden from 700x23 to mountain bike tires and everything in between for commuting. Of course, it's hard to remove the variables of the wheelset weight and bike weight. But I found 700x28 to be ideal for me for fast commuting. A little lower PSI adds more comfort without much hit on rolling resistance or weight. But it adds a level of security for me too, not sure why but seem to flat less with wider tires. I loved my 700x28 Gatorskins.

Conversely I'm running 700x32 Marathon's right now. They feel much slower. Heavier, harder to accelerate, sluggish. But, like I said, it could be other factors. I can't wait for them to wear out so I can go back to 28's.

Um, what? That's nonsense. It has everything to do with speed and weight. A wider tire has a larger contact patch and would be more secure, but there's a sacrifice in weight and aerodynamics to be made there. As it happens, road racing tires have more than enough traction for typical road conditions, so we don't need to run them wider than 23 or 25mm most of the time, and can benefit from the reduced weight and narrower profile. But they definitely don't give superior traction or reduce the likelihood of sliding out in a corner compared to wider tires.

I ride 32s on my Aurora and can't imagine going thinner for my commute. I'll be building up a bike with 35s in the next month, but I really wanted 38s, but that would have been cutting it pretty close, also couldn't find 38s in the tires I wanted... hope the 35 work for me... a fella at work rides 28s or maybe even 25s on his hybrid every day, says it works for him, but he's a skinnier guy than I. I'll take my steel bikes with big tires, he likes his aluminum frame with skinny tires...

I currently commute on a '97 ceramic composite Specialized frame with a Thomson post and 23mm tires. Probably as stiff and vertically non-compliant as you can get...I absolutely love it. My new build is a '90 Trek 750 (true temper 4130) that will be floating on 37's. I'm afraid I'm gonna get ruined to the comfort.

Fat Franks (26" x 2.35") for me. My favorite tires ever. Skinny tires make my flesh crawl.

what is the puncture resistance of those? any troubles?

Physics fail. Contact patch is inversely related to tire pressure, not tire width. Contact patch (sq.in.) = Weight(lbs) / Tire Pressure (PSI). Many wider tires run at lower pressure than narrow ones, but this isn't necessarily true. If there were racing benefits to a wider tire, then high pressure, wide tires would be widely available. They're not because no matter what the pressure, you have to corner slower on a wide tire due to the cornering profile.

Because few commuters are running at the performance limits of their equipment, the slower cornering issue is unlikely to affect their speed much.


Weight and aerodynamics may be an inescapable issue with larger tires in the racing context. Perhaps my use of the word "nothing" was too absolute, but these are definitely secondary disadvantages.

You're correct that contact patch area is primarily a function of pressure and weight. But the formula above is an approximation under the assumption that all parts of the tire in the contact patch area press down equally hard on the road surface. With real tires that's not the case and there's more pressure in the middle of the patch than at the edges.

But I disagree on your contention about cornering ability. Car and motorcycle races depend critically on cornering ability and if there were an inherent benefit to skinny tires then you'd find them in those sports. But the opposite is true - with quite wide tires being used. OTOH, in bicycle racing the most important concern is minimizing drag and weight since the available power is so limited. A skinny tire wins here in three ways: 1)air resistance is less, 2) higher pressures can be used for a given weight and construction therefore reducing rolling resistance, and 3) the weight will be less. And yes, the wider tire actually has a little less rolling resistance *if* both are run at the same pressure and are otherwise similar. But in practice the skinny tire can be run at much higher pressure than a wide tire of similar construction and at that higher pressure the rolling resistance will be less.

But for commuters these effects are pretty small. I regularly switch between my road bike with 23mm tires and my touring bike which currently has 38mm and 35mm tires. Can't say that I really notice much effect on my speed even in fairly fast group rides. But I'm pretty sure they'd become significant in any racing situation.

what took me by surprise (I did the opposite- went narrower- 32 to 28) was that I had to recalibrate my computer for a different wheel circumference. The compounding of that couple millimeter decrease in circumference resulted in a ride on the same route as my previous ride reading as 1-1.5 miles longer after I switched tires. Wild!

I want my next bike to be a Cross Check with 700x50 Fat Franks.

recently switched from 23 gatorskins to 25s. im liking it :)