Bicycle Tires are Rubber Coated Textiles

Its finally spring here in the Mitten State after a number of fits and starts. We never quite just ease into spring but its finally (mostly) here. So I’ll say it now, the Blogging is probably going to suffer a bit because I’m heading out to the Carriage House Workshop to make stuff. I’m also going to be outside playing a lot more, so less time in front of the computer is the consequence. I’m not going to stop blogging, just less. Maybe. We’ll see. You’ve been warned.

Its been a long winter of pouring through catalogs and annual gear guides looking at equipment I can’t afford, but somehow need: Wetsuits and Drysuits for kayaking, Bibshorts and Jerseys for biking,  Rainpants for camping, Drybags, sleeping bags, backpacks, tents…. I’m dreaming of heading back outdoors and using the textiles that are vital to helping me cope with the elements.

So Its time to change gears here at Textilesmithing. I’ve been looking at and writing about a lot of Art lately here on this blog and I’m sure there will be more writing about Art. However, one the reasons I started this blog was to look at textiles that are functional, textiles that enhance performance. Engineered textiles.

Last week over at Velonews there was a story about three things I love: Bicycles, Handmade Equipment, and Textiles. It was a story about FMB, a company that hand builds tubular tires that are so good, they’ve been on bikes that won Paris-Roubaix. At this point many of you are probably already asking “wait, what is a tubular tire and what is Paris-Roubaix?”

Cobblestone Torture

I’ll answer the second question first: Paris-Roubaix (A.K.A. “A Sunday in Hell”, “l’enfer du Nord”, “The Hell of the North”, “Queen of the Classics”) is possibly the single hardest day of bike racing on the professional circuit. It is a 260km race that takes place in early April (next weekend!) on the country roads of Northern France, of which about 50km are cobblestones. Not brick path, nor stone look, but Honest to god uneven cobblestones from days of old. This 100 year old race chews up riders, equipment, and tires and leaves them on the side of the road.  It is a monument of cycling that puts high demands on everything and is won on a combination of brute force, skill, strategy and dumb luck. To make things even more amusing, nature often deals a healthy helping of cold spring rain. (which is often better than the lung crushing alternative of warm dusty and dry.)

Last year’s Paris-Roubaix was won by Fabian ‘Spartacus’ Cancellara. His performance was so decisive that there were rumors circulating that he had a hidden battery powered micro-motor in his bike. (that rumor took hold enough that the governing body of cycling began random x-rays of bikes throughout the rest of the year.) Before the stupid rumors of the motor, there was talk about how he had custom hand sewn over sized tubular tires to help mitigate the vibrations of the cobbles. I think it was the tires + the bike + plus the fact that Cancellara is a motor. As for the battery powered motor on his bike: “It’s quite funny but it’s become a bigger story and is no longer so funny,” said Cancellara. “It’s a sad and really outrageous story. Believe me, my feats are the result of hard work.”

Tubulars and Clinchers

Still, you’re asking “what is a tubular tire?” I’m glad you asked, because I was never quite clear myself. I knew the basic concept but only enough to differentiate from the clincher tire, which most of us just knew as a basic bicycle tire… So now, lets take the time to take a deeper look at bicycle tires.

Bicycle tires are rubber coated textiles. They are made of thread, latex and a rubber tread, sometimes a steel wire is in the ‘bead’ of clinchers. A tubular tire is built around the inner tube. the tread and rubber surrounds the inner tube, either by gluing or sewing, then is glued to the wheel rim. A clincher tire is the tire you probably know. it is the tread that is inflated with a separate inner tube, and is held to the wheel rim ‘mechanically’ with a steel or thread bead. There are other variations, such as the no-tube clincher that works similarly to the concept of a car tire, where the tire is sealed to the rim and inflated. For this article, I’m focusing on clinchers and tubulars.

The Casing

Tubulars and Clinchers share much in common. they both have innertubes, and they both have casings made of thread and latex. The thread and latex casing is the wall that keeps the innertube from just blowing up like a balloon and gives the firm but flexible structure for the Tread to attach to. Bike Tire casing is made much like a warp for weaving is made, but only a single layer: Thread is methodically wrapped in a single layer around a stainless steel drum that is about the length of the bike tire. When the drum is covered with thread, it is then coated with latex. After the latex is cured, the thread and latex sheet is sliced off the drum. (diagonally)

Now that they have a single layer of casing material, it needs to be worked into a functional Tire. The casing material is cut across the bias, or at a 45 degree angle to the threads, into tire size strips. Two strips are laid over each other with the threads crossing perpendicularly. Then the outside edges of the strips are folded in. In clinchers, the bead is put into in the fold. What you end up with is a strip of material where the threads cross perpendicular to each other. It looks like a latex coated woven material cut on the bias, but is actually a double layer non-woven. Look closely at your bicycle tire sidewalls and you’ll see one layer of threads distinctly and the other layer subtly behind it. The tread of the tire, the rubber that meets the road, is glued to the casing.

Something you’ll see with most bike tire descriptions is TPI or Threads Per Inch. This describes how fine of thread is in the casing. When they wind the thread onto the drum it is spaced just tight enough that it fits side by side. So, the bigger the thread, the less TPI. Thinner thread = Higher TPI = a more supple ride, but a more fragile tire. Thicker thread = Lower TPI = a more robust tire, but a harsher ride. I’m cheap and, well, not so rich, so I generally go for the lower TPI tires that will last.

The Clincher

The clincher is what is now the standard bicycle tire. The casing material has a ‘bead’ built into it that is Steel, or Kevlar or other thick cord. (represented in yellow above.) Notice how the casing fabric is folded around the bead. The Inner tube is inserted into the tire and the tire then is held to the wheel rim with friction when the bead ‘locks’ to the rim. If you’ve ever changed one, you know that it can be a frustrating experience working the tire off of the wheel. The Diagram to the left shows roughly how the tire, inner tube and wheel rim interact in cross section.

The advantage of this setup is that the inner tube can be changed out in the middle of nowhere with only a few busted knuckles and you’re back in business. The disadvantage is that it is heavier and stiffer than a tubular. It is also prone to what is known as a ‘pinch flat’ where a bit of the inner tube gets trapped between the rim and the tire and a hole is ripped open. Luckily, if you carry some simple tools, a small pump and a spare innertube, you can be back on the road.

The Tubular

The tubular tire is what got me writing this post. I’ve never really looked at it and tried to understand what it is, vs. what the clincher is. The tubular used to be the standard bicycle tire. It is a tire that is built around the inner tube and then glued onto a wheel rim with a shallow curved profile. They are often referred to as ‘sew-ups’ but only the handcrafted tires are actually sewn anymore. mostly now, they are held together with modern adhesives.

The Rim for the tubular tire has no flange to hold it on. The tire is held on by ‘mastic’ glue. The advantages of this are: The Tire is held firmly and semi permanently to the rim. There is no chance of a ‘pinch flat’ so the likely hood of flats is reduced. Some believe that the tubular tire’s ride is more supple. The Rim and tire combination tends to be lighter than clinchers. The disadvantages: If a tubular flats, you have to replace the whole tire, which is difficult out in the middle of nowhere. This is why the classic race pictures always show the athletes with tires across their chests. (They had to be self sufficient.) Unfortunately, you don’t have time to glue that new tire to the rim, so it is a precarious spare that may roll off the rim if you corner too fast…

Modern racers still ride on tubulars but if the professionals get a flat, they just get a spare wheel change from the team car. The other advantage they have is that because the tubular is glued to the rim, there is little chance of it working itself off when flat, so they will often ride the flat until they get a wheel change.

Hand Crafted Tires

Worth a look is the story about FMB at Velonews. This is a small shop making tires from scratch. These tires are on bikes that win major races, and they are crafted:

“There are a total of 80 steps that go into making one tubular; in terms of man-hours, it takes about one and a half hours, but having to wait for the adhesive to dry means each stage takes about one to one hour, fifteen minutes. That is why we can only produce 130 to 150 tubulars a month. Any more than that and our quality will not be the same.”

I find it refreshing that there is still a market for hand crafted bicycle tires; that many professional bike racers choose for the harshest races the tire they can trust most: Not a mass manufactured tire that is arguably very high quality, but a hand crafted tire where every seam receives attention. These are guys with access to the newest technology, for free, and they buy workshop built tires.

The bike industry is going through a bit of nostalgia/customization/handcrafted revolution as of late. Perhaps its always been there, but the rise of the Annual Handmade Bicycle show, and the survival of manufacturers like FMB, Brooks Saddles, and many of the Italian shoe and saddle manufacturers gives me hope that there is a return to appreciation for quality product that can only be made better when made by hand. I understand that ‘made by hand’ or ‘hand sewn’ is a bit misleading, but there is something about the informed human touch combined with small manufacturing that gives me some hope that we aren’t going to outsource all of our production to the lowest bidder. Hopefully more and more of that kind of business finds its way into American small workshops.

Now, for your pleasure is a video of the ‘hand made’ tire production at Challenge.

ADDED 5-3-11: an excellent video of how Vittoria’s ‘handmade’ tubular tires are made in their factory.

Links:

Hah! found this as I was deep into writing the post: Poppy Gall Studio also has an interest in Bikes and Textiles: Handmade Bicycle Tires – FMB

A super in depth look at bike tires at Bike Race Info: Bike Tires Explained

The Late Great Sheldon Brown always had something to tell you about bikes: Bicycle Tires and Tubes

Jobst Brandt explains how to make a tubular tire: Making a Tubular Tire

Cyclingnews looks into Handmade Continental Tubulars: All Stitched Up

The story at Velonews about FMB: France’s FMB, tire maker for the cobbled stars

This entry was posted in craft, Customization, cycling, pavement. Bookmark the permalink.

6 Responses to Bicycle Tires are Rubber Coated Textiles

  1. Kathleen says:

    Great post, very interesting. Nothing to add, just wanted you to know your efforts aren’t wasted. Thanks.

  2. poppy Gall says:

    Hi Seth,
    Glad you discovered my blog post about FMB because now I know about you! Just got lost for a few long enjoyable minutes on your blog – I’ll need to come back later when I don’t have a huge looming deadline for work!

  3. Many individuals assume that wheels are created out of rubberized, because that’s what is noticeable. This is a significant oversimplification — rubberized is the least essential of the three elements that create up a tire.

  4. For most individuals and racers, clinchers are generally exactly where it’s from with regard to value. 1 high-quality tubular can expense up to the very best pair of clinchers.

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