Traditionally, clinchers sacrificed optimal aerodynamics in exchange for tire-changing convenience.
Clinchers or Tubulars? If you've been in the tri game very long, you've probably seen a dizzying number of opinions on the matter, both short- and long-winded. People often hold strong opinions about their rubber of choice, and you'll often hear these pundits claim that anyone on the other side of the fence is just plain ignorant. Well, nobody is wrong, or ignorant. People probably get so pointed about their opinions because they've become locked into their choice, and now must defend it. Clincher tires only work on clincher rims, and tubular tires only work on tubular rims. So once you take your stand, it becomes more difficult to switch sides. This editorial piece is meant to outine some of the major strengths and weaknesses of each format, for you to get the skinny and decide for yourself.
Some aero clinchers use a tradtional rim bonded to a carbon fairing, like the Bontrager Aeolus series.
Clinchers, also confusingly called "open tubulars," are tires whose outer rubber casing (the tire), and thin inner tube are separate. Clincher tires only work on clincher rims, This is the type of tire stocked on the vast majority of stock bikes sold with training wheels. When you get a flat, changing the tire is a fairly straightforward task. You remove the tire either by hand or with a lever, remove the tube, and throw on fresh rubber. In most cases, the tire itself can be reused. New tubes are only a few dollars each, so flats are relatively inexpensive as well. That's the main advantage of clinchers - they're easy to use, and easy to replace. You may have heard people throwing around the term "clincher convenience," and this is what they were talking about.
On the other hand, clinchers are heavier than tubulars, all else equal. Depending on what kinds of courses you're racing, or what kinds of roads you ride, this might not be an issue for you. But if your typical terrain is rolling or mountainous, it can be nice to have a little less mass on the bike, and light wheels are an easy way to save weight. In fact, they're becoming one of the only ways left to save weight as tri bikes become more and more integrated.
But, weight isn't a huge factor, and carbon clinchers are becoming lighter and lighter. But still, I have one big gripe about clinchers. And that's the pinch flat. Because the clincher tire is separate from the inner tube, the tube can sometimes get pinched between the tire and the clincher rim. It's sortof like a little tire hernia, which causes a flat. In theory, a proper tube installation prevents this from ever happening. But in practice, the wrong tube/tire combination can cause an inner tube to creep into the wrong spot when you least expect it. Even if you've been riding the tire for hundreds of miles, you could end up pinching at some point, as the inner tube can move around between rides when it's low or out of air. If you stick to certain known good combinations, you can reduce this risk dramatically. For example, a company like Zipp that makes its own rims AND rubber can be a safe bet. And maybe I'm just paranoid, or maybe I'm just a lousy mechanic. But I've had enough pinch flats to want to avoid them when I can. And I'll tell you one thing -- I've never ever had a pinch flat riding a tubular, because there's nothing to pinch.
Tubulars have stood the test of time, and are the choice of many pros and amateurs alike.
So what are the ups and downs of that age-old technology, the tubular tire? Well, we just saw one of the major pros - no pinch flats. And I already mentioned that they're lighter. To me, those are the two big benefits. There has traditionally been an aerodynamic advantage, which I'll describe below, but newer clinchers are just as aero, so that one's a push. Ultimately, the weight and the flats are the real benefit of these wheels.
So now we come to the negatives of the tubular tire. They are, primarily, the difficulty of tire installation, and the high expense of replacement. A good tubular installation takes several DAYS, to apply multiple coats of special glue, and really secure the tire to the rim. For experienced mechanics, this isn't a problem. In fact, I enjoy the process of coating the tires and securing them. It can be a messy ordeal if you aren't careful, but in the end, you've got a quality setup that's light, reliable, predictible, and fast. Of course, in the event of a flat, you'd better just whip out your cell phone, because if you've done the high-quality, three-day glue job, that tire is NOT coming off by hand. Some pros carry a razor to remove the tire, and a spare tubular in the event of a flat. I prefer carrying a tube of Vittoria Pittstop, and if that fails, I throw in the towel. Fortunately (knock on wood), I've never had to quit a race on account of tire failure.
The other issue is the expense. Tubular tires can cost anywhere from $50 to $150 per tire. And if you get a flat that Pittstop can't repair, you have to remove the tire (no easy task), remove excess glue from the rim, sand the rim a bit, and go through the entire three-day glue job again. In a race scenario, as I just mentioned, you can throw a pre-glued tubular on just to get you home, but it will need to be redone once your race is over. With a clincher, even an in-race swap can be a permanent one.
However, as bad as that inconvenience sounds, it's the poison I pick. In my experience, I get far fewer flats on tubulars than I do on clinchers, so I'm happy to go through the rigamarol of swapping tubbies in order to avoid all the pinch flats I used to get on clinchers. But plenty of informed riders come out the other way. As they say, your mileage may vary. Either choice is a legitimate one, and no one is wrong for choosing one over the other.
Need For Speed
Clinchers like Zipp's new Firecrest offerings are on par with tubular counterparts, and fast tires can be mated to either form.
Above are the major differences between these two formats. EVERYTHING ELSE comes out nearly equal. Or at least, everything else can be made to be equal. For example, a tubular wheel was traditionally more aerodynamic because it was easier to mate the shape of a tubular rim into a tubular tire to form a single aerodynamic unit. Clincher tires forced wheel designers to deviate from the ideal rim shape in order to include their aluminum brake track and retention lips. Most clincher rims still carry this design concession. But newer, cutting-edge carbon clinchers like the Zipp Firecrest series can more seamlessly integrate the clincher rim without resorting to an aerodynamic compromise. And moreover, the Firecrest hoops seem highly immune to pinch flats, perhaps because of their much wider rim bed. And the convenience of these things is quite compelling. I'm highly considering going back to clinchers because of these wheels.
It gets even trickier when you look at the more esoteric details such as tire rolling resistance data, or the difference between latex inner tubes or butyl ones (latex is a bit faster, but easier to pinch on a clincher). Looking at the minutia can make you go mad. But, in the end, the upshot is that you can get equally-fast setups in either clincher or tubular form. There are very fast tires to be found in both camps. Don't let anyone tell you the wheels are significantly different in this respect. You can go equally fast on either, provided your riding isn't extremely hilly.
Where do I come out? Again, because I absolutely hate pinch flats, I usually stick with tubulars. I have an old set of Zipp 303's with some beefy butyl tubulars that I use as my daily beaters. And on race day, I typically switch to a deeper set of hoops with latex tires. It's convenient too, because I can leave carbon-friendly brake pads on my bike at all times without worrying about transferring metal shards from the clinchers onto the carbon rims.
However, in the last year, I've spent quite a bit of time on Zipp's new wide carbon clinchers (Firecrest), and I have to say they're changing my mind. The wide design seems less prone to pinching, and the convenience is undeniable. At present, I'm training and racing on carbon clinchers. They're a little heavier, but I'm willing to make that trade.