Jan Heine, the publisher of Bicycle Quarterly, has a blog called Off the Beaten Track. In his current post, he discusses a favorite subject of his: wider tires. The question is, how wide is too wide?
Heine has done research into tire width and performance. “It’s a well-established fact,” he writes, “that wider tires roll faster than narrow ones.”
When comparing 21 mm tires to 23s and 25s, he found the 25 mm tires are fastest of that group. Going up in size, he compared 26, 29 and 31 mm tires on a super-smooth asphalt road, and found no difference in their performance. The 31 mm tires were no faster than the 25s, but they weren’t slower, either. On rougher roads, the wider tires rolled faster.
There has to be a point at which the width of tires becomes a hindrance. If so, Heine hasn’t found one up to 42 mm tires, which he informally compared to 25s, and found the wider tires ran just as fast. Even 42s don’t appear to be too wide, he says. And wider tires than that just won’t fit most bikes.
So, if wide tires roll as fast, or sometimes, faster than narrower tires, why don’t more cyclists use them? They’ve got advantages besides speed. They give a smoother ride. They use lower pressures, so can resist flats better. They’re safer, because they’re less likely to be caught in a crack or a railroad track. And because they handle rough roads better, they might even encourage cyclists to ride roads that might be avoided with narrow, high pressure tires.
I run 25 mm tires on my bike. I prefer them to the 23s I used to run, mainly because they’re a little more comfortable. I inflate the front tire to around 95 psi, and the rear tire to a bit over 100. They are noticeably cushier than the 23s I had, which had much higher pressures.
I’d love to try wider tires, but the fork of my road bike is narrow at the top, and the 25s are probably the widest tires I can fit. As I look ahead to what my next bike might be (not that I’ll be buying a new bike anytime soon), I think I’ll find something that can take wider tires.
How about you? Do you run tires wider than, say, 25mm? How do you like them? Would you recommend them to other riders? Where is the advantage — speed, comfort, or flat resistance?
curtis corlew says
Hummm. I know that the Marathons I’ve used, which are GREAT at resisting flats, are seriously slow. I’m sticking with my 23s on the road bike, For the commuter bike, wider and thicker are just fine.
If wider is faster, why don’t pros go wide? The only time they go even a bit wider is for the cobbles. You show me a tour rider on 32s and then we’ll talk again.
I love my Schwalbe Big Apple’s 2.35″. I’m riding a cargo bike, Surly Big Dummy, so speed is not the priority. That being said I can go pretty fast in it :). But I have taken those tires everywhere and ride them daily with ZERO flats (know on wood) and they are super comfy! I wouldn’t change them for the world but they wouldn’t be my choice for a speed bike.
I think one of the problems regarding big wheels and speed is the extra-wide and thus slower turning that comes with bigger wheels.
I run Schwalbe Marathon MTBs on my Big Dummy. 2.1. no flats, very cushy
I run 32s. love them.
Presumably, there IS a speed advantage to thinner tires, which is why the pros use them. The question is, just how big is that advantage and is it worth the discomfort to attain it? I mean, 120 seconds over a 250km TdF stage would be gigantic for the guy racing it, but not such a big deal for a weekend rider looking for exercise. Sadly, the amateur cycling world has convinced itself it wants to ride cheaper versions of the bikes the pros have. That means thinner tires and forks that will only accomodate thinner tires.
Interesting post. Definitely something to think about.
Mel Hughes says
I went to 28mm on my Litespeed. I am thinking about trying a 30mm if the profile is low enough to clear not only the front fork but the rear brake bridge and narrow enough to fit in the rear stays. On my Rivendell, I have 33mm Jack Brown Blues which have to be the most comfortable tire I have ever ridden on a road bike. But then, the tire clearances on the the Riv are enough that I could run a 40mm tire with a fender… I guess retro is pretty cool. If I could cram the 33’s into the Litespeed, I would. I don’t see any difference in speed but the comfort difference is enough that the Litespeed is rarely ridden these days.
Ray Garza says
I’ve been riding the Specialized 23/25 hybrid tires since I got my new Roubaix. They are 25’s with a 23 center ridge. With over 1300 miles on them they are Fast and comfortable with only a few flats. Not as fast as the Contintental 4000 but still pretty good.
Tire size is not the only factor that determines speed. You can get two tires of the same size but each have a different rolling resistance characteristics. Maxxis Re-Fuse and Contenttal 4000’s are night and day.