Je suis Charlie


Like everybody, we’ve been shocked by the terrorist attacks on the French satirical newspaper Charlie Hebdo. They are abhorrent, and I am glad that the French have stood united against this attempt to stifle free speech. (“Je suis Charlie” means “I am Charlie”.)

I also admire – unfortunately posthumously – the artists and editors at Charlie Hebdo. It takes courage to publish things that may offend. Few editors in North America dare this any longer. Here, most are concerned about the bottom line, whereas the people at Charlie Hebdo paid with their lives.

We don’t face that kind of threat at Bicycle Quarterly, but we have to admit to misgivings when we published some articles that we knew would offend some. The most recent example was “Tullio Campagnolo – The Visionary behind the Legend” which debunked many of the myths surrounding this legendary man, questioning whether Tullio Campagnolo really invented the quick release.

We knew that we’d lose some readers over this, and infuriate others. We published the article anyhow, and I am glad we did. It’s our job to provide information, to challenge the status quo (even if it’s only in the arena of bicycle history and technology), and then let our readers form their own opinions. As a result of this approach, we are no strangers to controversy. (Long-term readers will remember the Internet flame wars when we first realized that higher tire pressures don’t make tires faster.)

The attacks on Charlie Hebdo have affected all of us. We hope the newspaper will continue to publish (whatever we may think of it), and we vow not to censor ourselves for fear of offending.

Photo: Cycles Alex Singer, showing their shop window.


Posted in Uncategorized | 38 Comments

TPI and Tire Performance


Tires with supple casings are faster, more comfortable and simply more fun to ride. Most cyclists know this, but how do you measure “suppleness”?

A measure that often is used to describe the quality of tires is “threads per inch” (TPI). The idea is that tires with higher thread counts usually have finer weaves that make these tires more supple.

The reality is more complex, and TPI is of limited use when comparing tires. Here is why:

1. How do you measure? Ideally, you look at the TPI of the casing fabric before it is made into the tire. Casing fabrics vary between 15 TPI for coarse utility tires to 120 TPI for very high-end tires.

What about the tires with 300 TPI or more? These makers count every layer of the tire. Most tires have three layers of overlapping casing, so by that method of counting, a 100 TPI fabric will make a 300 TPI tire. And if you added a fourth layer for added puncture protection, you’d make the tire slower, but you’d bump up the TPI to a record-setting 400!

2. What is the diameter of the threads? The reason high-TPI tires usually are more supple is that the threads are thinner. If you keep all things equal, thinner threads will mean more threads per inch. However, if you make your weave denser, you also get more threads per inch, but actually a stiffer casing.

Panaracer, who makes our Compass tires, offers a 120 TPI casing. However, they found that if they use the same super-fine threads, but space them out a little further, they get an even more supple, and even faster, tire. So the Compass Extralight tires use that casing, which only has 90 TPI.

If you go by TPI alone, the Extralight casing looks inferior, but it’s in fact the more supple, faster casing.

3. How much rubber? Fabrics with very thin threads are fragile. They have to be handled very carefully during production. Some makers of budget tires compensate for this by covering the fabric with more rubber, which protects the threads. Of course, this makes the casing stiffer, and thus less performing. So one maker’s 120 TPI casing may be a lot less supple than another maker’s 120 TPI casing.

4. What material is used for the threads? With hand-made FMB tubulars, you get a choice of cotton or silk threads. The silk is much more supple than the cotton (which already is more supple than most polyesters). Even among polyesters, there are great differences in the thread materials. It makes no sense to claim that a 90 TPI silk casing is less supple than a 100 TPI cotton casing.

These are just a few of the factors that determine the tire’s suppleness. Let’s compare two hypothetical tires:

Tire 1 uses a stiff and relatively large-diameter thread. The fabric has a super-dense weave and is slathered with rubber. The maker counts every layer of the casing, and thus arrives at a 300 TPI tire.

Tire 2 uses a supple, superfine thread, woven into a relatively loose weave. The manufacturer keeps the rubber coating to a minimum. They report the TPI of the casing fabric, and arrive at a 90 TPI tire.

It’s easy to see that the Tire 2 above is superior to Tire 1, even though it has less than 1/3 the TPI. Suppleness, like so many important things, is hard to quantify, but you’ll notice it when you ride the tires.

Acknowledgments: Thank you to the engineers from Panaracer, Francois Marie of FMB tires, and Challenge Tires for the information contained in this post.

Posted in Tires | 21 Comments

The Biomechanics of Planing


We discussed “planing” in a recent post by looking at power data from a double-blind test of two different bikes. The data showed that the same rider’s power output was consistently higher on a bike with a more flexible frame than on a stiffer one.

On a bike with optimized frame flex characteristics, the rider can put out more power with less fatigue. We named this phenomenon “planing”. How does it work?


A cyclist’s power output is very uneven during the pedaling stroke. Even a professional racer with a beautiful spin puts out almost all of his/her power during the down stroke. This means that the bike is propelled forward by a series of brief accelerations, rather than a steady force. You can accelerate the bike/rider only so much during the short power stroke. Trying to pedal harder feels as if your legs are pushing against a brick wall.

The brick wall analogy is useful, because it shows that you can fatigue even when you aren’t doing work in the sense of physics. When you push against a wall, the wall doesn’t move – no work is done. Yet lactic acid builds up in your muscles, and you fatigue quickly.

Back to the bike and the power stroke: Imagine a bike that accepts extra power during the down stroke, rather than pushing back against your pedal stroke. Imagine that the frame stores the energy, and releases it at the end of your power stroke. This would lengthen the power phase of your stroke. Without having to accelerate the bike more, you would be able to put more power into it.


Frame flex acts like a spring. Finite element analysis models (above) have shown that almost all energy that you input into the frame as flex gets returned into the drivetrain, powering the bike. (Very little is lost to hysteresis – bike frames don’t get hot as they flex.)

This stored energy is released when the pedal stroke approaches the dead spots. The right type of frame flex thus prolongs your power stroke, allowing you to put more power into the bike without having to accelerate it more.

pole vaulter

In other sports, it is not a new idea to use flex to store energy and then releasing it in a beneficial manner. Pole vaulters use this phenomenon, and so did native American hunters with their atlatls. (Atlatls are sticks that throw darts with such force that they could pierce the Spaniards metal armour.) Jump-roping on a sprung gym floor is less fatiguing than it is on concrete.


We cannot be absolutely certain about the above explanation, because it is difficult to measure what is going on inside our muscles as we climb hills on a bike. However, our observations during the double-blind test are consistent with this explanation. On the stiffer bikes, our legs hurt with a burning sensation. This limited our power output. When we reached the top of the hill after an all-out effort, our heart rate was lower than its absolute maximum.

On the more flexible bikes that “planed” optimally for us, our legs did not hurt. The sensation was one of pleasant warmth in our legs, maybe a little tingling. With the legs no longer the limiting factor, our cardiovascular system set the ceiling on our power output. At the top of the hill, we were completely out of breath. Riding these bikes fast was fun, not painful.

The last part is the most important for me. I ride my bike for fun, and a bike that is more fun the harder I ride provides more of the exhilaration that draws me to cycling in the first place.


The bikes that “plane” best for us also are less fatiguing and more fun to ride at more moderate power outputs. On these bikes, we can ride long distances with minimal mental effort. It has been eye-opening to ride bikes where the act of pedaling becomes subconscious, allowing us to focus on the enjoyment of the ride, the scenery, and the friends with whom we ride.

• There are no action photos from our double-blind experiment, because all involved were focused on the test protocol. The photos in this post show other Bicycle Quarterly tests and rides.
• Further reading: Double-blind experiment: Bicycle Quarterly Vol. 6, No. 4. Power data from double-blind tests: Bicycle Quarterly Vol. 7, No. 4.
• Finite element analysis was done by Gary Houchin-Miller.

Posted in Testing and Tech | 84 Comments

Supporting the Classics


When we became custodians of the René Herse name, we had three goals in mind:

  1. Bring back some of the best designs of René Herse, so that today’s cyclists could enjoy their excellent function and aesthetic.
  2. Support classic René Herse bikes with components, so that they can be kept on the road, or get restored correctly.
  3. Protect the René Herse trademark.


We like these bikes so much, and we couldn’t stand the thought that someone might exploit the name, logo and designs without respect for the heritage – with only an 80-year-old lady trying to protect her family’s life work. So we suggested to Lyli Desbois, née Herse, that she sell the rights to the name, designs, tool, etc., to somebody who could take over the custodianship of the René Herse name and heritage.*


A big step happened a few weeks ago, when our registration of the René Herse trademark was approved by the U.S. Patent Office. While the trademark and designs were protected as soon as we bought the company from Lyli Desbois and started using them again, now nobody can claim that they didn’t know the trademarks were protected. There is no risk of the René Herse logo showing up on budget frames or cheap knock-off components.


These legalities aside, we also have made progress on the other points. Our René Herse cranks have proven themselves, and many riders are enjoying not just their beauty and light weight, but also their almost unlimited chainring choices.

And owners of classic René Herses can get chainrings again for their bikes, at least for the ones made after the mid-1960s.

Now we are proud to introduce a few additional parts for classic René Herses and other cyclotouring bikes.


Early René Herse’s bike were equipped with cantilever brakes of his own design. The brake pad holders were one-piece castings, which were designed for then-common short brake pads. The short pads cleared the fork blades and chainstays when the brake was opened to remove a wheel – a nice feature.

Decades later, the short brake pads had become obsolete. When the brake pads of René Herse bikes wore out, many riders fitted Mafac pads. These pads were longer and didn’t fit in the original holders, so riders installed Mafac holders as well – as on the bike shown above. As a result, the original Herse pad holders are very rare today. And the longer Mafac pads scratch the paint every time you remove a wheel…


We now offering replacement Herse brake pad holders. We made them a bit longer than the originals, so they fits Kool-Stop’s excellent Mafac reproduction brake pads. (Unfortunately, making replicas of the original pads is too expensive at this point.) To clear the fork blades, we offset the pad slightly from the mounting post. You don’t notice it, but it provides just enough clearance to open the brake all the way. The pad holders have the same angular aesthetic of the Herse originals, and they are also cast as one-piece units for durability.


Many Herse bikes lost their wonderful straddle cable holders over the decades. We now offer replicas that allow you to complete your restoration. Of course, you also can use them on any other bike that has centerpull or cantilever brakes.


Mafac’s centerpull brakes are found not just on René Herse’s bikes, but on many other classic and modern bikes. Their performance is without par, but unless you find a set of “New Old Stock” (NOS) brakes, they’ll have seen decades of hard use. Fortunately, the arms don’t wear out, and we now offer all the other parts you need to make a set of Mafac brakes better than new. If your brakes are equipped with plastic bushings that have developed play, you can use our brass bushings to restore the performance of your brakes. (We’ll offer a tool to press in the bushings soon.) Or you can get a complete overhaul kit that replaces every nut and bolt on your brakes.


Kool-Stop now makes replicas of Mafac’s “four-dot” and “five-dot” brake pads, but with modern rubber. They are available in black and with Kool-Stop’s excellent “salmon-colored” compound (above) that offers superior braking in wet and dry conditions. We have these in stock, too.


One of the things that makes René Herse bikes special are the custom-made screws and bolts. This practice came from his aircraft background: During the early 1900s, there were no standards for bolts. Aircraft makers made their own screws to ensure they were strong enough. A bolt failure on an aircraft can have devastating consequences! The aircraft builders designed their own head shapes, so mechanics in the field could immediately see if a bolt had been replaced by a generic one of potentially inferior quality.


Drawing on that tradition, Herse made his own bolts, too. The triangular heads for his M6 seatpost binder and stem bolts are truly iconic. We now offer replicas.


We also offer the smaller M5 screws with their distinctive round heads, which Herse used to attach racks and waterbottle cages. These screws feature rolled threads, super-strong CrMo construction and durable chrome-plating. They are great not just for restorations, but also for modern bikes where you want screws that look nicer and are stronger than generic stainless steel screws.


Herse also made special bolts to attach his brakes. The rear one features a built-in washer and a much sturdier head than the thin Mafac bolts that tend to break. The front bolts (above) were even more ingenious, as they incorporated a forward extension to attach a rack.

In recent years, these bolts have been imitated by many, but never equaled. The originals incorporated a washer, and the forward extension was smaller in diameter, because the rack pushes down on the bolt and so doesn’t need as much clamping force. We now offer replicas that match the originals 100%.


Many 1940s bikes from the best French constructeurs used fender eyebolts with round heads. They are so much more elegant than the large angular heads on current eyebolts. When I restored the PBP-winning Herse tandem, one of the more tedious jobs was making the classic eyebolts and matching cups – 9 sets. (Eight for the fenders, the ninth holds the battery-powered taillight to a fender stay.) Now we offer these eyebolts in two lengths: 7 mm (stay to fender connection) and 11 mm (stay to dropout connection).


Maxi-Car hubs are my favorite hubs. With double labyrinth seals, they spin smoothly for decades. Unfortunately, they haven’t been made in 15 years, and when you find a used one, it often doesn’t have the axle length you need. To help with this situation, we offer reproduction Maxi-Car rear axles in two versions: One drilled for quick releases (left) and 140 mm long, so it can be adapted to all rear hub spacings from 115 to 130 mm.

The second version is for a Nivex-style chainrest (right). It features a stub end that is drilled to receive the wing screw that holds it to the right dropout. The stub end ensures that the axle doesn’t extend beyond the outer edge of the freewheel, so the wheel clears the chain as it is removed.

Both axles are machined from CrMo steel and heat treated, so they are even stronger than the originals.


Our final product is potentially the most useful: We asked Gilles Berthoud to re-make the Sologne panniers in a classic model. Unlike Berthoud’s contemporary version with its plastic Klick-Fix attachment that tends to rattle, the classic panniers attach with leather straps and metal springs. This provides a relatively theft-proof and secure attachment that works on (almost) any rack, provided it has a spot where the hook at the bottom can attach.

I use these panniers for all my touring, since they are waterproof and the laces allow expanding or contracting them as my luggage needs require. I have one original set that was made in 1974, yet still is going strong. Quantities are very limited, since these are specially made by Gilles Berthoud in France for us.


We hope to expand these offerings in the future. Some high-end car makers like Porsche and Mercedes-Benz offer parts and support for the classics they made decades ago. We strive to provide the same service for the wonderful bicycles of René Herse.

Click on here for more information about our classic parts.

* In 2007, I negotiated the purchase for Boulder Bicycles, who bought the name from Lyli Herse. In 2011, Compass Bicycles Ltd. bought the trademark from Boulder Bicycles.

Posted in Components, Rene Herse cranks | 21 Comments

Happy Holidays!


Our best wishes to you for 2015! May the new year bring you wonderful rides and great memories.

Posted in Uncategorized | 6 Comments

Rides to Remember


As the year draws to a close, it’s fun to look back at the memorable rides we’ve done this year. And what a year it’s been! We’ve discovered new roads and enjoyed new adventures. The links in the text lead to posts that talk more about individual rides.


January started with those long miles to acclimatize to the bike again after the Winter break. It’s nice to ride with friends at an unhurried pace, stop at taco trucks, and explore new gravel roads in the foothills.


February saw my son and me riding to a family vacation. The idea started as a way to avoid renting a van or second car to fit all the children we were taking along. It turned into a backroad adventure, and when it snowed overnight, the ride back was even more fun than the ride there.


March had us visit Japan. It was a new world for us in many ways, but most of all, we enjoyed the incredible mountain roads. This one we nicknamed “Exciting Team Risk Road” after a sticker on a tuned Nissan that I had seen in a magazine. This little mountain pass was like a slotcar track, complete with crazy markings on the road in each of the sweeping turns and mirrors that allowed you to see around the corner.


The bikes that our friends at I’s Bicycle loaned us put quite a few kilometers under their wheels. We explored remote gravel roads, toured the Shinshu Mountains, and rode around Tokyo to visit framebuilders and bike shops. When our trip ended with a wonderful ride organized for Grand Bois customers (above), we were sad to leave.


April saw the Flèche 24-hour ride. Despite torrential rain, we had a good time, and managed to go further than we ever have in the Flèche. Having a tandem along helped our speed, and made it easy for me on the back to take photos, or even doze off to sleep – as long as I kept pedaling.


The Oregon Outback was in May. Nobody really knew what this event would be like – not even the organizers. It turned out to be epic – 530 km mostly on gravel. It was exciting, incredibly scenic, and very challenging. And it was a great test for different ideas about the ideal gravel bike. Best of all, it will be repeated in 2015.


June was a month filled to the brim with work. Fortunately, my job description includes testing bikes for Bicycle Quarterly, so we explored a connection of two valleys in the Cascades on a cyclocross bike.


A family vacation on Hawaii in July provided an opportunity to ride a different type of bike in a very different terrain. It was great fun, and I now dream of cycling up to the tops of Mauna Kea and Mauna Loa. What a challenge that would be!


The first Bicycle Quarterly Un-Meeting took place in September. We were blessed with gorgeous weather, and everybody had a great time, enjoying the wonderful roads and spectacular scenery. To be repeated!


October saw us in Japan again. We had a full schedule: touring Hokkaido, traversing the Shinshu Mountains at night, riding to an ancient Onsen during a typhoon… Perhaps the best was an impromptu ride organized by our friends to look at the autumn leaves on a mountain pass that is far off the beaten path.


November saw a few cyclocross races, as well as wonderful rides closer to home.


And just when it seemed like the cycling season was finally over, a sudden snowfall provided a unique opportunity to test a bike with a 2-day bikepacking trip to the Olympic Mountains. Who could stay home when roads like these beckoned?

Looking back over all these wonderful memories, I am glad that bicycles are able to provide us with these incredible experiences. What were your favorite rides this year?

Posted in Rides | 12 Comments

New Handlebars and Stem


One of the all-time favorite handlebar shapes is the Philippe Professionel. Back in the 1940s and 1950s, you found them on the bikes of professional racers (below), randonneurs, cyclotourists, even track bikes.


Their flat ramps provide plenty of hand positions, rather than forcing you onto the brake hoods like many modern bars. The medium-sized hooks provide enough room to be comfortable, and the long drops not only look great, but also allow you to roam in the drops. Few handlebars that are as comfortable, especially if you spend long hours in the saddle.


A few years ago, Grand Bois reissued these bars as their “Maes Parallel” model. They’ve become my favorites, too, equipping my 650B randonneur bike and even my cyclocross bike. (The bars on the Weigle at the top of the post also are Grand Bois version – you can’t tell them apart, unless you look at the logo, which is hidden under the bar tape on the Grand Bois model.)

Mid-century racers and riders (and the BQ crew) aren’t the only ones who like these bars: They have been one of our more popular products. However, many customers have asked for versions that are either narrower or wider than the 410 and 420 mm we’ve offered. That is where our new 400 and 440 mm-wide models come in. The widest bars are heat-treated for strength, and all pass the stringent EN “Racing Bike” standards for fatigue resistance.


We have many friends who ride modern bikes, and they were frustrated by the lack of similar handlebars for modern 31.8 mm clamps. So we worked with Nitto on making the Compass Maes Parallel 31.8 mm handlebars. Same great shape, but with a 31.8 mm handlebar clamp diameter. They are also heat-treated and tested to the highest standards.


To go with these and other modern handlebars, we now offer a stem for bikes with 1 1/8″ threadless steerers. It’s fillet-brazed from lightweight steel tubing. The stem is designed to provide a little extra height, so you don’t need to run a stack of spacers underneath. The clamp is on the front, which provides a cleaner, more elegant appearance. The stem is available in lengths from 80 to 120 mm.


The new Compass stem integrates seamlessly with the Grand Bois decaleur. This finally provides a reliable off-the-shelf decaleur option for riders of modern bikes, without bolts that come loose or parts that break off.

To clear the larger-diameter handlebars, you need to use a decaleur drop kit as shown in the photo above. We offer these drop kits with between 10 and 30 mm, so you can get the decaleur to match the height of your handlebar bag. (The decaleur does not replace a front rack; your bag still needs to be supported from below.)

I am excited by the possibilities that these new components offer. You can install the 31.8 mm handlebars on a modern racing bike to provide comfort for your hands, wrists and shoulders. Or you can use the stem and decaleur together with modern carbon-fiber handlebars on a randonneur bike. And you finally can get these bars in the width that works best for you, both for classic 25.4 mm and modern 31.8 mm stems.


All these products are made by Nitto in Japan. Nitto offers different quality levels. All are safe to use, but there are real differences in weight and finish. For all Compass components, we’ve chosen Nitto’s highest quality level, because we want our parts to be as light, as strong and as beautiful as possible.

I hope these new products will bring your dream bike one step closer to reality!

Click here for more information on our handlebars,
and here for information on our stems and decaleurs.

Posted in Handlebars | 33 Comments