Kimmo

I hardly ever get flats. I ride skinny tyres. I watch the road, and steer between debris.
Nature's caltrops.

DrIsotope

I don't think that-- while riding-- I have ever seen a goathead on the ground. The become apparent after they're already stuck in the tire.

Colnago Mixte

You gotta listen for them. The sound they make is a tiny little "Baaaahh!" like you'd hear coming from a baby goat. I think the fact they are so hard to see is a small part of the pure genius of the evil design of these monstrosities.

Learned a new word today, "caltrops". Never heard of those previously.

DrIsotope

robbyville

Colnago Mixte

What size tires? I hear that tubeless is not good for skinny road tires, because when you do get a puncture, the air leaks out really fast.

I've resisted tubeless so far, but if it can solve my goathead problems, that will definitely improve my quality of life not fixing flat tires by the side of the road, an experience that pretty much cancels out any fun you may have had earlier on your ride.

robbyville

I've had both 23 and 25mm road tubeless, depends on which wheel set I use and the width of the rim. Right now I'm down to one wheelset (Easton RSL 90's) with 25mm tires. The Schwalbe's on there have about 1000 miles on them so far and are looking good.

As mentioned, I'm the only one in our fairly large riding group using road tubeless. I've been using them off and on since 2014 and exclusively these last two years I'd say. Some people say that they don't like the ride, or that the ride feels deadened somehow. I'm not sure about that they seem to ride as well as my previous tubed wheels even when swapping back and forth. The other complaint people very often have is the difficulty in mounting tubeless tires. Other than some Fusion's about 4 years ago I've never had a problem mounting.

I can't speak to the air rushing out really fast since I've never had a flat with any of my tubeless set ups. I can tell you that about 6 months ago I had a rear tire with a ton of nicks and cuts that finally got deep enough where I could hear a hissing sound when I was stopped. I got off my bike and looked at the tire, saw some sealant bubbling through one of the cracks and that was it. The sealant did its job, I lost a few pounds of pressure but was still fine to finish the ride (which happened to include a 4 mile downhill so I was plenty scared of flatting), but had no additional air loss.

I have pulled a few goat head barbs out with no worries, but like you mention, sometimes you just don't see them, I just hear them going around and around like a tree seed covered in sap that gets on the tire at times.

wphamilton

Not to get involved in your argument, but it reminded me of something I was thinking about with respect to the different sized tires and pressure. While the area of the contact patch depends entirely on pressure and axle weight, the shape of it will vary between the wide and narrow tire. Specifically, the width. It seems to me that the greater width would lead to more flats, and a greater length not so much.

Narrow high pressure tires have longer and skinnier contact shapes, and wider and lower pressure tires have shorter and wider shapes. So that would add to the chances of running over something and flatting, in addition to having the greater area due to lower pressure.

The other variable is, is it easier for a wire or thorn to penetrate the higher pressure or the lower pressure? I've seen that argued back and forth but it isn't resolved in my mind.

HTupolev

I really don't see how higher pressure wouldn't make it easier, since there's more force pushing the object into the tire.

Thorns? I had one ride last year, on 53mm Rat Trap Pass ELs with zero puncture protection, where I picked up tons of scary-looking thorns on my tread while riding over grass covered in loads of thorn branches. Sharp enough to hitch a ride, more than long enough to puncture through. I rode 20 miles of pavement before sweeping them off, didn't flat.

My guess is that, if the stabby things in question are aggressive enough that they'll go through at any pressure being considered, then a wide tire might be more likely to flat, due to the wider contact area picking up more stuff. But if the wider tire allows low enough riding pressures that the stabby thing won't easily penetrate, then I suspect it could be more durable.

noglider 

Wider tires don't get more flats. And you have shown bad preparation for the inevitable puncture.

wphamilton

Less wiggle in the rubber maybe. The stiffer tire might turn the object or fling it while the lower pressure tire holds it in place. That would be advantage thin tire. There's more force for the puncture if the lower pressure tire stays in contact with the ground (taking more of the weight off the stabby thing), advantage wide tire. I'm not sure which is more important.

That's more or less what I think.

Plus, while the greater width makes it more likely to roll over something, it also makes it more likely to sag down on the side of it, taking some of the pressure off as you point out. I don't know which is more important.

Colnago Mixte

Easy experiment. Ride two bikes through the same goat head patch, one with 20 mm tires, and the other with 40's.

Count the number of thorns in each tire. I would imagine that the 40's will have picked up roughly twice as many thorns, if not more than that.

However, the wider tire, holding more air, will have a much better chance of getting you home before it goes flat. Advantage 40 mm tire, in that regard at least.

kbarch

You know, the title of this thread was meant as a rhetorical statement and a complaint, not a truth claim, but it has been interesting to think about the implications.

And I'm sure that everyone who thinks about it will realize that the key variable is nothing to do with the tire and everything to do with the presence of stabby little things and (for those who ride under-pressurized tires) potholes in the tires path; if you never encounter them, you'll never get a flat, regardless of how wide your tire may be or how little armor it may have. Unfortunately we have little or no control of the cause of punctures.

Colnago Mixte

I think at the end of the day, the composition and durability of the tire matters more than width, with regard to the number of punctures I personally get.

I've settled on a 5 mm thick. tire in 28 mm for combined road and dirt road use. For me having the thick tread has kept every thorn I have actualy picked up (maybe a 3-4 on 2 bikes in hundreds of miles of riding) from ever getting in deep enough to puncture the tube, I think the rubber is also very tough, that helps as well in keeping the thorns from ever penetrating the tire to begin with. But YMMV, etc., etc.

DrIsotope

I still think it's interesting. My anecdotal data says that narrower tires are more likely to suffer catastrophic failure (less material? higher pressures?) but I can also see how a wider tire might be susceptible to picking up more... junk.

It's not going to change my habits one way or the other-- one bike gets skinny tires, the other bike gets chubbier ones.