The Actual Width of Tires?


Sometimes we get an e-mail or a phone call from a customer asking, “I bought the Compass 32 mm tires, but they only measure 28.5 mm on my rims. Why is this?”

Decades ago, some tire makers cheated when stating tire widths. Why? To make their tires appear lighter than they really were. By selling a 25 mm tire as a 28 mm, they made the tire seem lighter than the competition’s tires, which actually were 3 mm wider.

That was long ago, and it’s not what is going on here. We label our tires as close to their actual width as possible. Here is why different people report different widths for their tires:

  1. It can be difficult to accurately measure the width of a supple tire.
  2. The casing of supple tires stretches for a few weeks or even months after they have been installed.
  3. Tire width depends on tire pressure and rim width. That means the actual width can be a little narrower or wider than the nominal width.


I recently installed a set of Compass Barlow Pass Extralight 700C x 38 mm tires on a Bicycle Quarterly test bike. How wide are they really?

When you measure metal with calipers, you squeeze the calipers until they won’t go any further, and then read your measurement. If you compress the calipers on a rubber tire, the tire will deflect. In this case, I measured 34 mm. But that isn’t the actual width of the tire: If you tried to fit the tire into a frame with just enough clearance for 34 mm tires, it would rub.


Here is how you measure tire width: Open up your calipers in 0.5 mm increments. Check whether there is “play” between the caliper jaws and the tire. In the photo above, I am already at 35.5 mm, and the calipers still fit snugly on the tire.


At 36.5 mm, I am finally getting some wiggle. This means that the tire is just over 36 mm wide. That is the width when it’s new.


Two weeks later, I measured the tire again. It has stretched to 36.5 mm. I was surprised that it was still so narrow, until I checked the tire pressure. I had let the pressure drop to about 30 psi. How wide would the tire be at its maximum pressure?


I inflated the tire to 75 psi, and lo and behold, it now measured 37.5 mm. It probably will stretch a little more, and achieve its full 38 mm width before long. Of course, I wouldn’t ride it at that pressure (unless I put it on a tandem), so at the pressures I usually ride, the tire will be a tad narrower than its nominal width.

Should I inflate my tires to a higher pressure to make them wider? No, that doesn’t make sense. Your tire’s comfort and performance is determined by the tire width at the contact patch, which gets larger at lower pressure. Putting more air than necessary into the tire defeats the purpose, even if it makes the tire wider where it does not touch the ground.

For narrower tires, rim width also plays a role. The Compass Stampede Pass tires measure about 31 mm on a 20 mm-wide rim, like a Mavic MA-2, but 33 mm wide on a 23 mm-wide rim, like a Grand Bois rim. For wider tires, this is less of a factor, since all the rims we use are narrow when compared to the wide tire.


In any case, our testing has shown that the material and construction of the casing are more important for comfort and speed than a millimeter or two in width. When you put a set of supple Compass tires on your bike, you’ll notice a huge difference in how the bike feels and performs.

And when you buy your next bike, make sure to spec a frame that provides ample tire width. On my own bikes, I am not too concerned whether the tires measure 39 or 41.5 mm. Either is ample for most of the riding I do.

Further reading: How Wide a Tire Can I Run?

Posted in Tires | 26 Comments

A Japanese Book on Simplex


Hideki Sasaki has released the second book in the “Derailleurs of the World” series. The new book covers Simplex, perhaps the most influential derailleur maker of all. From the earliest 1920s designs to the last slant parallelogram derailleurs of the 1990s, they are all documented in their many variations.

Simplex is a fascinating story. I loved seeing the early front derailleurs that were found on those wonderful 1930s Reyhands. The ubiquitous “Tour de France” model that equipped so many post-war racing bikes. The crazy Juy 543 that fetches such incredible prices on eBay. The first twin-pivot parallelogram derailleurs, which then led to the wonderfully light and jewel-like SLJs of the 1970s and 1980s. Mixed in with these gems are the abysmal plastic derailleurs that ruined Simplex’ reputation once and for all. Yet even those somehow look appealing when photographed in brand-new condition in the studio.


If you ever wondered how to distinguish an SLJ from the 1970s from a later 1980s one, or what the difference between the SX and the SLJ was, you’ll find the answers here. The text is in Japanese, but the photos – now in full color – are wonderful, and you don’t need to read Kanji to figure out model number, capacity, weight and manufacturing dates.

These books are hard to find outside Japan. We placed a one-time order of 15 copies. I am keeping one, and the others are available while supplies last. The Campagnolo book in the same series sold out within two hours, so if you want a copy, don’t delay.

The book has 117 pages, softcover, and costs $ 68. Since this is a special order, we won’t put up a page for it in the Bicycle Quarterly bookstore. Instead, go straight to our shopping basket to order.

Update 7/12/2014: All the Simplex books are sold. Thank you for your interest.

Second and last order 7/14/2014: Due to the number of disappointed customers who missed out on the first batch, we’ll place another order. We’ll also receive another shipment of the first volume on Campagnolo. To receive a copy, you must pre-order here by 7/16/2014.

Posted in books | 2 Comments

Thoughts about Getting Children Engaged in Cycling


Many avid cyclists would love to share their joy of cycling with their children, but some find that their children aren’t interested at all. I am lucky – for now – that my son shares my love of the sport. How did this happen?

It’s a good question, and I cannot claim to have found the magic bullet. I think the most important aspect is that your children need to discover cycling for themselves. If you push them into any sport, there are typically two outcomes: They either become compliant clones of you without much personality of their own, or they rebel against you and never touch a bike. Neither outcome is what you want.

My son showed no interest in bikes for a long time. It was only when his younger sister taught herself to ride with a neighbor’s bike, that he, too, wanted to learn to ride. We have an alley with infrequent traffic and they typically rode there with the neighbor children. We then went on some rides around the neighborhood as a family, and we took the opportunity to teach them how to ride in traffic and anticipate problems before they occur.

A year or two later my son graduated from a $3 yard sale one-speed to his first real kid’s cyclocross bike (shown below). Then he started to enjoy cycling. We equipped his bike with a custom-made rack, fenders and lights. I made up outings that the two of us could go on, like around Magnolia (5 to 10 miles), and I’ll have to admit to adding an enticement of a stop at a local ice-cream shop.


We rode together to music lessons, basketball, soccer, museums… He soon started riding by himself to his activities. Then, one day, he decided to “go on a ride” by himself. He tried to retrace a route we had taken before. He got lost and discovered some interesting streets and sites. When he found his way home, he clearly had been bitten by the bug of cycling. He tested his new-found freedom by riding places that I thought a bit challenging, but he did OK. He learned to navigate by landmarks, such as the ship canal that bisects Seattle, and he always found his way home. (He knows our phone number, just in case, and I taught him how to fix a flat.) When he’s “bored”, many times he’ll decide to go for a ride or out for a run.


When the Islabike test bike arrived last summer, he read in the product description that it was suitable for cyclocross, and he wanted to try that. The result was a wonderful season of ‘cross last autumn. Lately, he’s joined me on longer rides on this bike. We’ll see where it all goes. He is still young, and his interests range wide. I don’t know whether he’ll enjoy cycling for the rest of his life – for the moment, I am just enjoying our rides together.

The impetus for each step in his cycling came from him, and I think that is important. On the other hand, my daughter had little interest in cycling for a few years, and that was OK, too. Both have to develop their own, unique personalities, and it’s my job to connect to them in their own worlds, rather than try to drag them into mine.

To summarize, my suggestions include:

  1. Don’t push your child toward cycling, but allow them to join you when they want to. Make sure your rides together are suited to their abilities.
  2. Buy a good bike for your kids. The cheaper ones are usually not much fun to ride. Don’t worry that they’ll outgrow it – good bikes have high resale values, so you’ll get most of your money back. More importantly, you don’t want to miss the opportunity to have them enjoy cycling.
  3. Trust your kids, and work with them to increase their responsibilities and range. Don’t be afraid to let them ride by themselves once they have shown that they are competent in traffic.
  4. Let your passion be a habit that your children observe in you, and allow them to define their own passion.
  5. Be proud of your child(ren).
Posted in Rides | 30 Comments

A Reappraisal of Tullio Campagnolo


When Bicycle Quarterly did an article on Tullio Campagnolo, you knew it wasn’t going to be another fluff piece re-hashing the same old stories and myths. We did some real research, and we were surprised by what we uncovered.

Cyclists who know their history have heard how in 1927, Campagnolo raced in the Gran Premio della Vittoria, got stuck in the snow when he could not open the wingnuts on his rear wheel, and lost the race. He then invented the quick release, which became the foundation of the company that bears his name.

That is the legend, but what is the real story of Campagnolo? Working with well-known cycling historian David Herlihy and other experts, we’ve pieced together the history of Campagnolo. Based on research in European archives, patent searches and contemporary accounts, the conclusions were published in a 19-page article in the Summer 2014 Bicycle Quarterly. The true story is different from the myth, but it’s no less fascinating.


Campagnolo was less of an inventor of ground-breaking innovations, and more of a visionary who foresaw trends and even shaped them. He adopted other manufacturer’s promising, but overlooked, ideas. He showed great ingenuity in improving those ideas to give racers exactly what they wanted.

Back to the quick release: It appears that Campagnolo did not invent it at all. The story of the race in the snow is a myth. There was a snowy Coppa della Vittoria, but in a different year (1925), and Campagnolo isn’t mentioned in the race reports as a favorite in any of the Coppas della Vittoria of the 1920s.

The original patent for the quick release, said to date from 1930, does not exist. Later patents by Campagnolo are written very narrowly for improvements or special features of the quick release, indicating that he could not patent the cam-actuated quick release itself.


Campagnolo’s next major innovation was a parallelogram derailleur, which introduced the general shape and operating principle for all rear derailleurs to this day. Campagnolo got this idea from a French cyclotouring derailleur, the Nivex (left). He was not the first to adapt the parallelogram derailleur for racing bikes, either: That honor goes to the JIC derailleur (middle). As so often, Campagnolo integrated these ideas into a product that was more elegant and better finished (right). His derailleur was successful where the other parallelogram derailleurs were not.


Campagnolo’s true strike of genius was the idea of the “gruppo” – a group of matching components. Before, customers of high-end bikes had to choose each component individually: brakes from Mafac, derailleurs from Simplex or Huret, hubs from FB, cranks from Stronglight or Gnutti, etc. Tullio Campagnolo made the customer’s choice easy by offering a full group of components. “Full Campy” became the hallmark of a top-of-the-line bike during the 1970s bike boom.


Campagnolo focused on the complete customer experience long before Apple popularized the concept. Campagnolo’s packaging was beautiful. The components showed balanced proportions and a beautiful finish. The quality was without reproach. The parts were easy to install and pleasant to use. Campagnolo backed their components with an unconditional lifetime warranty. And the company sponsored so many professional racers that more than 90% of professionals rode on Campagnolo (below). As a result, Campagnolo dominated the high-end component market for decades.


This is a major re-assessment of Campagnolo’s legacy. It reminds me of the re-evaluation of car maker Ettore Bugatti’s contribution in recent decades, from undisputed genius to a more human entrepreneur, who nonetheless imbued his products with a quality and mystique all of their own. I feel that understanding Tullio Campagnolo’s true contributions, as a visionary more than as an inventor, will only increase the appreciation of him and his company.


The Bicycle Quarterly article delves into many other questions. Why did Campagnolo patent and introduce his quick release not as a wheel retention mechanism (as we know it today), but only as a shifting aid? Why did he introduce a Nivex-style chainrest in the 1970s? Why did a French inventor who developed bar-end shifters and a novel front derailleur become the distributor for Campagnolo in Paris? And why did Campagnolo not continue to develop his components during the 1970s, which left an opening for Shimano’s rise in the 1980s? It’s a fascinating story – it probably would make a great movie!

Click here for more information on the Summer 2014 Bicycle Quarterly.


Posted in Bicycle Quarterly Back Issues, People who inspired us | 26 Comments

Our Last Mountain Passes in Japan


It all started innocently enough. We had taken the Shinkansen bullet train from Tokyo to Kyoto in the morning. We were to spend our last weekend in Japan with our hosts, Ikuo and Harumi Tsuchiya of I’s Bicycles, in Miyama. Wouldn’t it be splendid to ride to Miyama, rather than drive? It was only 80 km (50 miles), just across a little mountain pass. We’d been up the pass from the other side. It shouldn’t take more than 3 hours to do the ride. What could possibly go wrong?


It was a warm afternoon when we left Cycles Grand Bois in Kyoto, wearing just our short sleeves. We left our touring bags with our hosts, who would carry them in their car. We didn’t bother to re-pack and transfer extra clothes into our handlebar bags. This was just a quick ride, after all!


We found our way out of Kyoto without problems. Then the road started climbing. Steeply. For kilometer after kilometer, we worked hard in our small gears. Then we remembered that Kyoto is almost at sea level, but Miyama is located in a mountain valley. No wonder the pass was longer from this side.


Finally, we reached the top. To our surprise, it wasn’t the pass we had climbed from the other side. We checked our map and the GPS: We were on the right road. Then it dawned on us: There were two passes. We only had climbed the first one, and we had one more to go. It was getting late, and this high in the mountains, the temperature plummeted. The sign indicated 5°C. That translates to 41°F.


And here we were in shorts and short sleeves. Hahn was lucky to have a vest, but he had goosebumps, too. Without any extra clothing, I just shivered.

We embarked on the descent. It was as steep as the climb had been. We got into the aero tuck, not to gain speed, but to minimize our exposure to the wind.


Just as I started to worry about hypothermia, we entered a tiny village. Hahn spotted a beverage vending machine on the roadside. Can you believe it? A machine that serves hot and cold beverages. Japan really is a dream country for randonneuring!

Neither of us spoke or read Japanese, but fortunately, the hot beverages had red labels to distinguish them from the cold beverages with their blue labels. We almost randomly pushed red buttons, and I ended up with lemon-flavored tea. It tasted great, but even more importantly, it was the perfect temperature: ready to drink, yet warming me from the inside.


I felt better now, but there was more descending ahead. I rummaged through my handlebar bag and found our airline confirmation printouts. Just like racers in the old days, I put the papers under my jersey to act as a windbreaker.


Somewhat warmer now, we could enjoy the beautiful mountain valley. There was no traffic at all, just little villages dotting the hillsides. We drank in the scenery, knowing that we’d miss Japan once we left a few days later.


All throughout our trip, we had chased the cherry blossoms, which mark the onset of spring. We started in the southern lowlands of Osaka and ended in the northern city of Fukushima, traveling alongside the cherry trees in full bloom, as spring moved northward.

Now the trees in the high mountain valleys were blooming. It was a magical sight in the twilight. Spring had arrived even here, just as our trip was coming to its end.


Not speaking Japanese had added interesting challenges to our trip. But you don’t need to read Kanji to understand this sign: More climbing ahead! We were approaching the second pass.


And climb we did. Japanese mountain roads are incredible: beautifully laid out, with switchback following switchback. Often, they are just a single lane wide, but convex mirrors at each blind turn allow you to see the road ahead, so you can corner with confidence.

It was fun to ride here, but darkness was falling. I was concerned that the second descent would be even colder than the first.


In the twilight, we finally reached the pass. To our relief, it was the same pass we had climbed from the other side. At least there wasn’t a third pass!

Now it mostly downhill to Miyama. We enjoyed the dozens of switchbacks on the descent. We were lucky – the temperature had not fallen any further. There was no ice on the road!

At the bottom of the pass, we turned on our headlights. We time-trialled the last 30 km or so to Miyama. This kept us warm, but mostly, we were concerned that our hosts might be worried when we didn’t show up on time. We arrived half an hour late, but with great memories of an amazing ride.

And we learned once more that dangers lurk not in the big adventures, where every detail is meticulously planned. It’s when you think a ride is not a big deal that you let your guard down and don’t think of the risks that hide in plain sight. Lesson learned: From now on, I will pack my long-sleeve jersey and tights on every ride over unknown terrain.

Photo credit: Harumi Tsuchiya (2nd from top).

Posted in Rides | 10 Comments

What to Do with a Bad Book?


I am cleaning out the Bicycle Quarterly Press library. I am keeping all the great books or those that we may need for reference later. This even includes two editions of Eugene Sloane’s Complete Book of Bicycling, which I bought mostly because they had some grainy images of René Herse and Alex Singer bikes – the only information I could find in those pre-Internet days.

But there are a lot of books that simply aren’t good enough to keep.


It’s amazing how much has being printed on bicycles in recent years that has not stood the test of time. Hastily produced efforts on “custom bicycles” with fuzzy photos pulled off the Internet. A history of Campagnolo that appears to have been written in two weeks by somebody only marginally familiar with the company.  I’ll give these books to a local charity. Despite their obvious flaws, somebody will enjoy them…

One book though, has me stumped. It’s a lavishly produced book on Cycling Science, coming from an academic source, the University of Chicago Press. The problem with it is simple: Much of it is wrong.

I know that the science of cycling can be contentious. There still are people who believe that higher pressures will make a tire roll faster. Others insist that stiffer frames perform better. These can be considered gray areas where the science is evolving. However, in this book, the errors are unequivocal.


Take the illustration above, for example. It purports to show the influence of aerodynamics on the performance of a bike. It shows how fast Chris Boardman, who holds the absolute hour record on an upright bike, would have gone on various types of bicycles, with the same power output.

The chart is obviously wrong. Even I can go faster than 9.2 mph even when riding in an upright position. Do I really put out more power than Boardman during his hour record? Does this mean I just need a superbike, and I’ll break Boardman’s record?

Of course, the chart is wrong. Boardman himself rode a standard track bike to a record of 30.7 miles – way more than the 20.9 miles the book predicts for the “tucked down with hands on drops” position. This is just one of numerous errors…

When a book contains many glaring errors like this, I don’t even want to give it to charity. It seems wrong to spread information that is obviously incorrect, and to poison the minds of people who cannot afford to buy better books on the subject. Right now, the book is in the recycling pile. What would you do with it?

Posted in books | 34 Comments

Challenge + Teamwork = Fun


My most memorable rides involved a challenge and friends. We came up with a goal, and then we set out, as a group of friends, to achieve that goal. What followed was a magical ride full of seamless teamwork. We traded pulls. We enjoyed the scenery together. We took turns struggling on the hills. And when we finished, whether we had achieved the goal or not, we basked in the warm afterglow of having given our best.

Even when I was racing, the best moments were about challenge, not competition. The long breakaways, where everybody worked smoothly, trying to stay ahead of the peloton. There is something about working together, rather than against each other, that is a source of true, lasting happiness. By contrast, the joy of winning a final sprint to the line was fleeting for me.


My most memorable challenge, and one of the best rides I have done, was the original Cyclos Montagnards challenge in 2009. It all started with an article in Bicycle Quarterly (Vol. 8, No. 2). Raymond Henry portrayed the constructeur Paul Charrel from Lyon. During the 1930s, Charrel had set himself a challenge: Ride from his home town of Lyon to the top of Mont Ventoux and back in 24 hours. He attempted this feat six times, but never succeeded, always foiled by the strong Mistral winds and the rough roads. (He did succeed in other challenges he set himself.)

When I read the manuscript, I was mesmerized. I called Mark and told him about Charrel’s challenge. There was a moment of silence on the line, then Mark said: “We have to do something like that!”

What would make a good challenge? I suggested Seattle to Windy Ridge on Mount St. Helens and back, but Mark rejected that as not far enough. We’d easily make it in 24 hours. To be a real challenge, the outcome had to be uncertain. What if we added Sunrise on Mount Rainier? That would be 530 km (330 miles). We would visit the two highest roads on the largest volcanoes of the central Cascade Range. Together with Cayuse Pass, there would be three major climbs. It seemed doable, but far from certain.

I called Ryan, and he was excited: “This is right up my alley!” This goal gave our training a new impetus, and we enjoyed many spirited rides in the Cascade foothills as we got in shape for the big ride. We looked at maps and planned the best route. We thought about when to start and where we’d be able to find supplies. Planning the ride already was a lot of fun.

Finally, in late July, the snow had melted on the high passes, the weather forecast was favorable, our bikes were tuned up, and we were ready to go. After dinner, I rode to Mark’s house, then we picked up Ryan. At 7:33 p.m., we had our cards signed at a coffee shop in the Leschi neighborhood of Seattle.

For the next 24 hours, the clock would always be ticking! We made good progress on our way south. We skirted the western flanks of Mount Rainier on empty roads in the middle of the night. Just before 1 a.m., we made our first stop in Morton, a lumber town with a 24-hour gas station. An hour and a half later, we turned off the empty highway and started our ascent of Mount St. Helens. For three hours, we climbed this massive volcano. We did not see a single car during this time, but plenty of deer and a porcupine. We reached Windy Ridge at sunrise, right on schedule. The huge crater of the volcano was bathed in the pink light of the rising sun (photo at the top of this post). It was an incredible feeling to stand there, realizing that we had ridden all this way since dinner.


As we turned around, we saw four volcanoes in a stunning panorama: Mount St. Helens to the west, Mt. Hood to the south, Mount Adams to the east, and right in front of us, our next destination, Mount Rainier.

The day that followed saw vertiginous descents, breakfast at a small coffee shop, and long, long climbs. At high elevations, the wildflowers were in full bloom, but we were struggling in the heat. As we reached our second destination, Sunrise on Mount Rainier at 6400 feet, our goal looked elusive. There was even talk of abandoning, of calling somebody to pick us up.


Of course, you don’t abandon a ride on top of a huge descent, so we rolled downhill toward Greenwater. In Greenwater, we agreed that we could continue to Enumclaw. And once we reached Enumclaw, Mark mentioned: “If we continue at this pace, we might, just might, make our goal.”

That was enticement enough, and we raced the last 50 miles back to Seattle. We lost a few valuable minutes trying to find our way through the maze of streets in Kent, and the last few rollers on Lake Washington Boulevard were painful for our tired legs. But we knew that barring a mechanical mishap, we would make it back in time. And we did, reaching the café in Leschi at 7:12. We had made our goal with 21 minutes to spare. The barista working the evening shift was the same one who had signed our cards the day before. He was incredulous: “Did you really ride all this time?”


The immediate aftermath of the ride was anticlimactic, as it often is. Mark had given the most and suffered from dehydration. Ryan was exhausted and lay on the floor. Even so, we all made it home fine, on our own bikes.

And ever since, we keep talking of the day when we rode and rode, covering this incredible distance under our own power, and having one of the greatest times of our lives.

Rides like these are the reason we fine-tune our bikes, test tires and geometries, think about where to carry our gear, and how to optimize our stops. We love our bikes because they allow us to do these incredible things. Every winter, we talk about that ride and think about other challenges we can do in the coming year.


We opened up the Cyclos Montagnards Challenges to all riders, since we want to share this experience. Other riders have designed their own challenges in a similar spirit. We hope to add a few more to the list in coming years.

We also are excited about the Super Randonnées 600 km rides, organized under the auspices of the Audax Club Parisien. Over a distance of 600 km, these rides include at least 10,000 m of elevation gain, and you have 50 hours to complete the ride. There are three in North America right now, and more all over the world.

Challenges can be large or small – all it takes is come up with a ride that pushes the boundaries of what you think you can do. My first challenge was to ride 120 miles to visit my parents for my father’s birthday during my first year in college… That was more than 25 years ago, and it seemed huge then. That ride built my confidence for longer, more ambitious rides, which have kept my cycling exciting and fresh ever since.

What are your favorite challenges, past or future?

Further reading:

Posted in Rides | 22 Comments