Tuesday, April 17, 2012

10 Fascinating Facts About Inner Tubes

NOTE:  This post is rated R for an instance of mature thematic content.


I tuned up the Albert fleet on Saturday, and in the process came to a shocking realization about bicycle inner tubes.  I tried to explain it to my wife, which led to another shocking realization about inner tubes.  Pausing to reflect, I realized that this seemingly unexciting bike part actually presents a vast store of fascinating lore.  I share that lore herein.

I should perhaps mention that in writing this I assume you care about bikes, bike parts, the dynamics of mixed marriage (which in this context means a bike person married to a non-bike-person), childhood cruelty, and/or gearheaded stuff in general.  If you don’t care about such things, you may want to skip this post.  Not sure?  Take this brief quiz. 

1.  Which of these is/are not a type of bicycle inner tube valve?  (Select all that apply.)
a.      Presta
b.      Presto
c.       Proust
d.      Schrader
e.      Shrader
f.        Schrödinger’s cat

Score:  if you yawned, rolled your eyes, sighed heavily, or muttered grumpily during the quiz, you should probably read something else.  If you answered b, c, e, and f, read on—this is your kind of post.  If you answered something other than b, c, e, and f, and are disappointed not to have achieved a perfect score, you should enlighten yourself—keep reading!

Fascinating fact #1:  you can run out of inner tubes

Obviously this fact isn’t fascinating, or even interesting, in the context of most bicycling enthusiasts.  But for a veteran rider in possession of a garage, it’s almost unbelievable.  A seasoned cyclist builds up an endless supply of inner tubes, and while it’s true they tend to be punctured, the growth in their numbers seems as boundless as the growth in world population.  It’s like the tubes actually mate and produce offspring.  As a renter, I actually had a complaint once from my landlord about my collection of tubes and tires being a fire hazard.

So:  this weekend.  It was my trusty commuter, Full Slab, that had a flat, and though I successfully patched the tube, the valve spontaneously failed when I went to inflate it.  No problem:  I pictured my pile of inner tubes, which in my mind was like a giant nest of black snakes.  But is it turned out this pile was not only depleted but completely gone.  Had my wife thrown my tubes out?  I’m sure she’s been sorely tempted, but she wouldn’t dare.  For the first time, I had to contemplate the idea that I could actually be out of tubes.  What would I do?  Actually buy some?  I haven’t bought a tube for my commuter bike in decades.

Finally, when I thought to look among my endless supply of tires, to see if a tube was hiding in one of them, I did find one—and the tire it was in was in better shape than the one I’d planned to use.  But still, this was a close call.  I was rattled.

Fascinating fact #2:  spice don’t care

As I washed black grime from three bike repairs into the clean white kitchen sink, I described my amazing no-more-tubes hypothesis to my wife.  She replied, perhaps a bit testily, “I thought you had boxes and boxes of those.”  I conceded that I have a couple of Vittoria EVO-55s new-in-the-box, but that I’d never waste one of them on Full Slab.  “I can’t even get the EVO-55s anymore—nobody seems to carry them,” I lamented.  She replied, “This is where I excuse myself from this conversation.”

On the one hand, I shouldn’t be surprised by my wife’s lack of interest.  But wasn’t this the same woman who bike toured across the country with me, and commiserated when I was getting two punctures a day in southern Arizona?  I had no more anticipated her lack of interest than she can believe that I really don’t care about camouflage chic, silhouettes, or a person’s “colors.”  (Come to think of it, she is probably as nonplussed by my stockpile of jeans as she is by all my spare bike tires.)

I suppose there are marriages where both parties are equally interested in cycling, but I’m not sure I’d want to be in one.  (What if a couple straddled the great Campagnolo/Shimano debate?)  In most cases, the minimal overlap in men’s and women’s interests looks something like this:

For details on that (fascinating!) overlap, click here.

Fascinating fact #3:  tubes once spawned a game like Russian Roulette

Imagine four teenage boys sharing an unfinished basement:  that’s a great way to build up an amazing stockpile of inner tubes.  One day my brothers and I decided to get rid of the pinch-flatted tubes that couldn’t possibly be patched.  So we got out the Zéfal Plus “Double Shot” floor pump—a monster with two air chambers designed for maximum inflation speed—and took turns pumping ten strokes into the inner tube while the others plugged their ears.  We  kept going until the tube exploded, which in the confines of the basement made a deafening bang.  Then we tied off the ends of the exploded tube and went at it again.  Of course the tied-off tube exploded even sooner.  We did this again and again.  It was terrifying when one of my brothers would somehow escape the explosion so I was sure to get it.  The pump took both hands to operate so there was no ear-plugging for the hapless pumper.  The tube would get grotesquely, unbelievable huge, and would actually tremble with over-inflation before exploding.  The brutal game went on for at least an hour.  I hope the hearing aid industry makes great strides in the next few decades.

Fascinating fact #4:  valves can fuel sibling rivalry

During high school, in the mid-‘80s, I worked at the High Wheeler (aka Thigh Feeler) bike shop in Boulder with my brothers Geoff and Bryan.  (Our other brother, Max, had worked there prior to us, but we never quite managed to all be on the payroll at once.)  One summer Geoff and I worked the same shift, building new bikes all day long.  We had an ongoing disagreement about the usefulness of valve rings.  I argued that they helped you keep the valve straight, helped you get the pump chuck on there, and enabled you to ride a flat without the tube bunching up around the valve.  He argued that … wait a second, this is my blog, I’m not going to bother giving his silly arguments!  He can comment on this post if he wants his position articulated.

Geoff was forever stealing the rings from my bike’s valves (whenever I went on break), to deprive me of them.  I had to keep spare valve rings on me in case I discovered his treachery too late, like during an after-work ride.  In retaliation I was forever putting rings on his bike’s valves.  There was a lot of cussing.

Every new bike Geoff built went out without valve rings.  Based on the rings’ being metal and shiny and knurled, he couldn’t bear to throw them out so he saved them in a little box on his workbench.  One day I collected like twenty of them and put ten each on his valves, all stacked up.  This had the added benefit of putting his wheels off-balance.  Plus, he couldn’t fight back in like fashion:  my bike only ever had two valve rings to remove.  Geoff responded by hiding his spare valve rings.  I scrounged up a couple more somewhere and this time I used Loc-tite and screwed them down good and tight with a pair of pliers.  Geoff got his revenge by putting reflectors on my bike’s wheels and pedals.  I got back by taking apart his bike’s headset and mounting a big front reflector.  Et cetera, all summer long.

(Full disclosure:  I have stopped using valve rings, though I carry one with my spare tube.)

Fascinating fact #5:  how you inflate your tubes says a lot about you

It’s tempting to divide all cyclists into two groups:  those who use a pump, and those who use a CO2 cartridge.  To me, a pump makes all the sense in the world.  You can use it as many times as you want, it doesn’t tend to malfunction, and it doesn’t generate waste (in the form of an empty CO2 cartridge that ends up in a landfill).  You also run less risk of discovering the hard way that the tire isn’t seated properly on the rim, because a pump fills the tube so gradually.  The cartridge user strikes me as the kind of convenience addict who also favors the Rabbit corkscrew and the plastic squeeze bottle of ketchup.

Zoom in on that photo:  “Our CO2 is obtained from a naturally ocurring [sic] volcanic source.”  I ask you:  is there any other naturally occurring volcanic source than a volcano?  And why bother gathering your CO2 from a volcano when naturally occurring CO2 is all around us?  I’d be far more impressed if Genuine Innovations managed to gather the CO2 emitted by a bike race peloton, where each racer increases his carbon footprint with every breath.

Bike pumps also reflect the ideology of their users.  For decades I used the Zéfal HPX, the greatest frame pump ever made.  Here it is (I’ve added a cat to provide scale).

Should everybody use this pump?  No, function isn’t everything.  There’s a great argument to be made for the classic old plastic Silca, with the Campagnolo steel head.  Aesthetically, that product approached the platonic ideal of bike pump and to this day I sigh to think of its perfection. 

Never mind that those plastic Silcas tended to foomp.  Foomping is where something goes wrong in the pump head and the full pressure of the tube, compressed mightily by a skinny bike tire, bursts back into the pump, blowing the handle and shaft right out the back and across the road.

I haven’t been consistent myself with regard to bike pumps.  After a few decades I got sick and tired of my Zéfal rattling, and as my strength waned with age I started to care more about weight, and switched to an absurd Silca mini-pump that barely works.  On a solo ride, I spend like ten or fifteen agonizing minutes forcing enough air into the tube to limp home.  On group rides, I keep from wasting everybody’s time by borrowing a proper frame pump.  To the extent the owner of the proper frame pump despises me, he is justified.

But that still doesn’t cover the spectrum of inflation options.  You also have foolish children (and childlike adults) who take their bikes to gas stations and use the compressors there.  A car tire requires a huge volume of air, so these compressors are really tricky.  You can explode your bike tire in the blink of an eye.  Bike shop compressors are better behaved, of course, but lots of mechanics I’ve known still used a good old floor pump.  Why?  I don’t know.  Love of precision?  Love of effort?  Fear of compressors?  It is true that even a bike shop compressor will turn on you occasionally, if you haven’t seated the tire right.  Once Bryan had inflated a high-pressure 2-inch-wide Tioga City Slicker and then noticed the bead popping off.  High pressure and high volume is a terrible combination—it’s terribly loud when it blows.  He dropped the compressor hose and gripped the tire with both hands, squeezing it to the rim to keep it from blowing off.  “Help!” he cried.  “Somebody come let the air out!”  We all just plugged our ears and pitied him.  He ran to the back door of the shop and threw the wheel.  The tire exploded—BLAM!—in mid-air.

A final group I shouldn’t leave out are the homeless.  Homeless bicyclists sometimes go dumpster-diving for tubes and tires and then ask the shop to loan them a pump or compressed air hose to inflate it with.  At the Thigh Feeler, we took care when throwing out a tire with a tear in the sidewall.  If the tire could be booted, we’d often take it for ourselves.  If not, we’d use a utility knife to utterly destroy the tire to make sure some homeless guy didn’t pluck it from the dumpster, fail to see the sidewall tear, mount it to his bike wheel, and end up crashing due to a sudden blowout.  Sometimes we’d get chewed out by a homeless guy for this practice.  (Boulder may be the only place I know of where the homeless feel such entitlement.)  One time a homeless guy begged to borrow our compressor hose, ignored the mechanic’s caveats and warnings and advisories, pumped up his tire, looked at us haughtily like we were all idiot yuppy scum, and pedaled off.  Twenty feet away—BLAM!  The tire blew, as did the guy, spewing profanity as he stalked off dragging his crippled bike beside him.

Fascinating fact #6:  self-sealing tubes really do work

In the early ‘90s, I worked at The Square Wheel bike shop in Berkeley.  One day we took delivery of a flashy new product:  the Specialized Airlock self-sealing inner tube These tubes carried an unconditional guarantee from the manufacturer.  I was skeptical, but they really did work.  As a demo, we had a mountain bike wheel in a truing stand with a big knobby tire and the Airlock tube installed.  I would do endless demos, driving a nail right through the tire with a hammer.  Air would start hissing out, and then I’d give the wheel a good spin, and within seconds centripetal (or was it centrifugal?) force would force goo into the hole, and the hissing would stop.  We did these demos constantly and never failed to get gasps from our customers.  After hundreds of such punctures the tube finally gave up the ghost:  it had run out of goo.  The next time the sales rep came around, I handed him the tube and asked for a warranty replacement.  He inspected the countless holes, laughed, and credited us for the tube.

I couldn’t help but notice the number of one-star reviews for this tube (click that last link to see).  As I’ve noted before, I can’t always relate to these one-star reviewers.  Maybe these tubes have gone downhill since the early ‘90s, or maybe these reviewers just don’t have the touch.

Fascinating fact #7:  inner tubes spawned an urban legend

At this same shop a fellow mechanic recommended latex inner tubes for tying up your girlfriend.  He boasted that both he and his girlfriend absolutely loved latex tubes for this.  Amazed, I informally polled the other mechanics and several of them agreed:  “Oh, yeah, latex tubes are the best for that!”

Now, I cannot be sure, but it seemed then and it seems now that this was urban myth.  I can totally understand how anybody handling a latex tube—which is as soft and smooth as kid leather—might wonder if its extraordinary tactile properties aren’t wasted on a product that spends its life inside a bike tire.  There’s also an obvious inclination to equate this bike-oriented latex product with the only other latex product young men are typically familiar with.  On the other hand, those tubes are fricking expensive and bike mechanics are usually so broke they won’t even fork out for latex tubes for their bikes.  Moreover, was this kind of kinky stuff really that common?  The only way for me to suss out the truth would have been to interview the girlfriends, but I wasn’t about to open that Pandora’s box.

Fascinating fact #8:  any valve core can be replaced

The first successful non-replaceable-valve-core replacement, which is the only one on record, was achieved in July of 1999.  Since this is as amazing as the first heart transplant, I am proud to say that I was the one who pulled it off.  (Full disclosure:  I’m merely the only person I know of who has done this.  Surely others have not only done it, but would say “We used to do this all the time, and what’s more, we didn’t even have…” and so on.  But for the purposes of this essay let’s agree this is impressive and you’re impressed, okay?)

I conceived of the idea as my wife and I drove to Moab, Utah for a mountain biking vacation.  Right before the trip, I’d snapped the end off of the presta valve on my mountain bike, and the extra tube I’d hastily pulled from my pile had a huge pinch flat and probably couldn’t be patched.  I grimly contemplated how badly a bike shop in Moab would gouge me for a new tube.  I couldn’t face that prospect.  So I pondered the possibility of fixing the valve.  I figured I could push the broken-off valve end into the tube, then cut a small hole across from the valve.  I’d then extract the valve guts from the donor tube and insert them into the valve stub through the hole I’d made.  Then I’d patch the access hole and be good to go.  I mentally rehearsed the operation over and over, looking for any reason why it wouldn’t work.  I had been quietly ruminating on this for a good while as we drove along, and finally my wife asked me what I was thinking about.

“You first,” I said, feeling trapped somehow by her question.  She’d never understand … would she?  She replied, “I was just thinking that once we have a house, we can get a piano, and a kitten, and have a baby!”  Great.  Now I was really stuck.  She continued, “Now it’s your turn … what were you thinking about?”  I had nowhere to go.  “I was pondering the world’s first inner tube valve-core replacement,” I confessed.

You may be interested to know that the valve replacement was a resounding success.  To this day, that tube is performing flawlessly in my mountain bike.  If you spin the wheel slowly, you can hear the quiet ticking of the old valve core as it rolls around inside the tube.  (If you do not find this interesting, you may yet be interested to know that my wife and I do have a house, a piano, a grown-up kitten, and not one but two children.)

Fascinating fact #9:  how you fix flats says a lot about your life

For this next bit I’m indebted to my teammate Marty.  As he expounded on a ride a few years back, puncture repair and phase of life are closely related.  As a teenager, you carry a patch kit on rides and patch the tube right there on the side of the road.  As a pre-adult, you carry a spare tube, and patch the original tube when you get home (so the number of tubes you own is always n+1 where n is the number of wheels you own).  By college you’ve got a few extra tubes and don’t always get around to patching the old one right away.  Once you’re working and making money, bike wheels start to accumulate, and when you run out of non-punctured tubes you just swap out the wheel.  By your forties, you have multiple bikes and can’t be bothered with swapping out a wheel, so when one bike has a flat you just ride the other one.  Eventually, in your fifties, all your bike tires go flat through disuse and you can’t be bothered even to pump them up.

My own experience matches this pretty well.  As a teenager, I was too cheap even for a proper patch kit.  There was only one patch kit on the market back then, because it was (and remains) the finest of its kind ever conceived.  I’m talking of course about the Rema Tip Top Two-wheel repair kit:

What you see there are the remnants of my last kit (I used up the last of the cold vulcanizing fluid patching Full Slab’s inner tube) along with a couple of vastly inferior patches from a modern, cheap, lame patch kit.  It disgusts me even to look at them.  Anyway, the only change in the Rema Tip Top since the 1970s is that they no longer provide a tiny little rubber tube whose function nobody could ever figure out to begin with.  It didn’t attach the tube of vulcanizing fluid, and was too small in diameter for the fluid to even flow through.  My personal theory is that it was included merely as a conversation piece.

But as I was saying, I was too cheap even for this exalted product.  I carried around a little bottle of super-glue and some squares of rubber cut from old inner tubes.  This worked pretty well until one day in the winter of ’85 when a friend and I were riding the Morgul-Bismark.  I punctured, and couldn’t repair the tube because it was too cold for the glue to work.  It was about 20 degrees out.  My pal, as it turned out, didn’t even have a patch kit.  I can’t remember how we eventually got my bike back running; probably I had to shove the patched tube down my shorts or something.

In the intervening years I’ve gone through dozens of new tubes, as the punctured ones piled up.  I have gobs of patches, but the vulcanizing fluid always dries out.  A couple years ago when my wife asked what I wanted for my birthday, I described in great detail the cans of Rema Tip Top cold vulcanizing fluid, with the brush built into the lid, that we’d use at the Thigh Feeler.  With one of those babies, I could patch every single one of my tubes and have plenty of fluid left over.  But my wife must not have been paying attention—she must have heard “blah blah blah fluid blah blah patch tubes blah blah blah” because what she went out and bought me was not a big can of cold vulcanizing fluid, but just a little tube of it.  At least she got the right brand.

By the way, if you’re annoyed at my constant use of the term “cold vulcanizing fluid,” I confess that it’s one of my pet phrases, my use of which I realize almost begs to be mocked.  In fact, my wife has mocked me for it, and for “Syncromesh,” “double-clutch,” and “constant-velocity joint.”  So, yeah … pile on.

Suffice to say, being out of this fluid is exactly how a veteran cyclist builds up his seemingly inexhaustible stockpile of inner tubes.

Fascinating fact #10:  the mythical “third valve type” does exist

Look:  it’s neither Presta nor Schrader! 

This is on a kids’ bike I got from my brother Geoff, who now lives in the Netherlands.  You pump it up with a Presta pump chuck, but there’s no little valve top to unscrew.  I have no idea if this valve type has a name. 

If I had a son, he’d probably be really proud to have these special valves on his bike.  My daughters, who each had their turn with this hand-me-down bike, were less than impressed.  I guess they take after their mom.


  1. "I've added a cat to provide scale." I literally laughed out loud. LLOL. I really wanted another parenthetical statement for the next photo: "(again, cat added for scale)" I'm sure you meant to put it in there and just somehow forgot at the last minute. -- John

  2. It's called a Dunlap valve. They're great because you don't have to use tools to remove the valve core thingy.