Friday, April 24, 2009

Equipment - Why Tubulars?

On the bike forums someone asked a standard question for those who ride on the road, one that seems much more pertinent after my little tutorial on gluing tires:

Why tubulars?

Such a simple question, such a difficult answer. Especially after reading a couple posts on how to change a tubular tire (and how long it takes to finish it). Let's put it this way - a tutorial on changing a clincher doesn't take two posts to complete.

So, let's ask again. Why tubulars?

Tubulars are fun. They put you in a different mindset. It's that flahute mindset, the gritty lowlander Euro pro who rides box section rims over all sorts of adverse terrain and makes it look easy. Or the sleek aero Tour look, skimming along on tall, dark, logo-covered carbon wheels. You can subscribe to either fantasy but both of them work better on tubulars.

Tubulars (or sew-ups) are tires that have a tube sewn into them (hence "sew-up") instead of a tube that is easily separated from the casing. The latter type of tire is called a "clincher", because the tire has a bead that clinches the rim.

This is where a neatly cut up tubular would come in handy, as well as a neatly cut up clincher. Let me get my sheet metal sheers and I'll be right back.

(Okay, since we're in Vegas right now, and I didn't find a tire I wanted to cut up before we came here, I don't have a picture of a real cut up tubular).

There are a number of reasons for using tubulars.

The primary one, for a racer, comes from the tubular tire system's lighter weight.

Although the tire itself may not weigh substantially less than a clincher/tube combination, the rim can be built significantly lighter. Zipp's lighter tubular wheels are down to 1000 grams a set, where as a light clincher set costs you 300-400 grams more.

The reason is the tubular tire holds its own pressure - pump one up to its maximum pressure while unmounted from a rim and it'll just turn itself inside out. Pump up an unmounted clincher and its tube to anything over 30 or 40 psi and you'll have a gargantuan tube that will, at some point, explode in your face. In fact this used to be the preferred "starting pistol" at some mountain bike races in the area (Mount Snow, to be exact). Clincher rims have to be strong enough to hold in that pressure; tubular rims do not. Because of this structural requirement, clincher rims inevitably weigh more than a similar tubular rim.

Even a perfectly good clincher rim may be manufacturer limited to a certain pressure. For example, Campy limits their super expensive Hyperon clinchers to only 118 psi. Imagine what happens to that rating after you slam that sharp edged pothole while cruising along at 30 mph in the middle of a crit. Speaking of which...

A second reason cited for using a tubular addresses durability.

Because the tubular rim has no bead, it has a correspondingly low chance of pinch flatting. The round tubular tire construction means there is very little chance to pinch the tube between two parts of the tire wall.

This means you can ride lower pressures without too much worry about flats. Tubulars seem to be softer anyway, but see my disclaimer line at the end. Whatever, I can ride 170 psi if I want to, or down to 120 psi, and it feels fast and resilient either way. As a note, my Contis need 170 to feel fast, and it's not skittery at that psi, CXs are good at 110-120, 140 on an "A" day.

I've only seen one guy double flat tubulars, and that happened right in front of me. A friend had a pair of TriSpokes and, at about 45 mph, hit something so hard that not only did he flat both tires, he also dented both rims. I later bought them from him, bending out the sidewall bulges with ChannelLocks, but the rims were never the same. Yet I raced on them regularly for the last ten years or so.

I also got a pair of similarly damaged clinchers. But because the sidewall is integral to holding the tire's shape properly, I had to lace new rims on them to make them usable.

With tubulars your tire doesn't depend on a perfectly formed rim wall to contain its high pressures. The tire holds its own pressure. In addition, the tire relies on glue to hold itself onto the rim, unlike a clincher.You can ride the most banged up, dented, crazy weird tubular rim with 100% confidence because the rim only supports the base of a tubular tire - it does not do any air pressure related work, nor does it retain the tire in any significant way.

I was amazed at how bad the wheels were that the pro teams Z and Gatorade were riding in the now-extinct Tour Du Pont. On the Hershey stage I spent about 2 hours watching mechanics work on bikes after the day's stage. My "pros ride awesome bikes" myth got shattered that day while I watched the best pros's bike getting worked on by tired mechanics. Some wheels were bad enough that I would have swapped out the rims, but the teams just keep them going. One mechanic put Superglue into some cuts on Lemond's tire, albeit after some discussion about replacing the same tire. However, for lessor riders like Gatorade's Dirk DeWolf, for example, he had such major flat spots on his rim that it must have shaken out a filling or two any time he went over 30 mph.

Yet these bent up tubular rims have about the same functional strength as a straight tubular rim. On the other hand, a messed up clincher rim is just asking for trouble if the tire doesn't seat properly. Your tire may blow off such a rim at any moment, with no warning. I'm sure you've seen (or heard of) rims that blew apart due to overly worn sidewalls. This will happen on clinchers, but not necessarily on tubulars.

Tubulars also let you ride even after you've flatted.

You can do this because when the tire goes flat, it becomes flat and somewhat firm due to the fact that it's glued in place. A clincher tire, on the other hand, becomes a wiggly thing that goes all over the place because it relies on air pressure for securing the tire in place as well as its shape.

With a flat tubular you can go quite fast in a straight line. I wouldn't recommend going too fast in a curve, and for hard turns you'll definitely have to slow. Part of the speed depends on how well you glued your tires - I use a screwdriver to start peeling the tire, and only after about 1/2 of the tire is off can I rip the rest off by hand.

One (Pro) Worlds was won on a totally flat rear tubular. If it was a clincher he'd have been screwed:

Fricken awesome clip. Insane.

Longer non-English version, with 6 more clips to give you the lead up to the finale:

Disclaimer line: I think there may be some cognitive dissonance factors (sound, "feel", etc) but I figure I'm just rationalizing riding tires that cost more than the ones on the missus's car. So I don't count them.

Would I train on them? Have I trained on them?


Have I flatted them while training? Of course. Do I regret riding them? No. Even when I flat, after that initial shocking disappointment (usually I flat when I move over for traffic, then I berate myself for being to nice), a flat tire turns my normal, ho-hum training ride into a chance to, well, be a pro for a few miles.

So, yeah, what you do is train on them, and when you flat, you pretend you're Olano with 2k to go or something, and you go super hard till you get home. Then you see what you did to your rim. And maybe you regret spending a lot of money on the tire and the kind of dented up rim, but man was it fun blasting home on a flat. Or catching a couple guys out on a hard training ride. Or motorpacing some random cars at 30 mph. Etc etc etc.

Life gives you lemons, make lemonade.

That's the point to riding, right? Having fun?

Tubulars are cool. They're cool because they're light, they're fast, and they're fun.


No One Line said...

A friend of mine has been cajoling me, trying to convince me to make the transition to tubulars. I would probably enjoy it, but then I look at the state of my four bikes' tires right now... I'm leaving for the track in a few minutes and last night I had to do some tire swapping to make sure I had a bike with tires that had enough integrity to race on. I should buy a bundle of new tires but I'll have to wait until my new job's payday. I wonder what a situation I'd be in if I had tubulars without back-up clinchers. I mean, booting gashes in clinchers with scavenged business cards might only be a quick fix, but at least you can keep a sinking ship more or less afloat for a while. Tubulars would be hard on my budget, especially after reading the chapter in Fournel's "Need for the Bike" about him flatting his twenty-sixth tubular in one summer.

Someday. Maybe someday soon if I just stick to fronts for a bit.

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