Myth 6: Tread Patterns Don’t Matter on the Road

To celebrate 15 years of Bicycle Quarterly, we are examining 12 myths in cycling – things that we (and most others) used to believe, but which we have found to be not true. Today, let’s look at tire tread.

“Bicycles don’t hydroplane,” declared some experts many years ago. “Hence, tire tread patterns don’t matter on the road.” The first part is true – even wide bicycle tires are too narrow to lose traction due to hydroplaning – but the conclusion assumes that tread pattern only serves to evacuate water from the tire/road interface.

The reality is more complex. I once cycled on the polished stone that surrounded a college library, and I was surprised by the lack of grip: I crashed. Even though I was unhurt, I learned the hard way that the coefficient of friction between our tires and the rocks that make up the road surface isn’t very high.

If our grip came only from pure friction, the size of the contact patch wouldn’t matter. Physics tells us that if you double a tire’s width, it will be pushed into the road surface with half as much force – the two cancel each other. Yet race cars run ultra-wide tires because they provide more grip. What is going on?

Tires interlock with the road surface. Imagine each little surface irregularity like a spike that pushes into the tire. The wider the tire, the more surface irregularities it touches; hence it has more grip. A softer tire also has more grip because the road surfaces pushes deeper into the tire. That is why the tires of race cars use very soft rubber, and why wider bicycle tires at lower pressures offer more grip than narrow ‘racing’ rubber at higher pressures.

There is another way to increase the interlocking between tire and road: provide edges on the tire that ‘hook up’ with the road surface irregularities. Each edge provides a point where a road irregularity can hook up. The more edges you have, the better the tire hooks up.

This isn’t a new idea – back in the days when rubber compounds were less grippy, all racing tires used treads that were similar to the Compass tire above. I often wondered about these ubiquitous tread patterns, until I found the answer in Bike Tech, a long-defunct newsletter about bicycle technology. Under the headline “The Importance of Real-World Results,” a Michelin engineer described the interlocking mechanism, and explained that, especially in the wet, interlocking is what gives a tire much of its grip.(1) If the surface is ‘greasy’ when it first rains after a long period of  dry weather, friction is even less, and the interlocking is even more important.

That matches my experience. In theory, the friction between road and tire should be less than half when it’s lubricated with water, and yet we can corner at about 2/3 of the ‘dry’ speed in the wet – at least on good tires (and when the road is just wet, rather than greasy).

This doesn’t mean that the rubber compound of the tire tread doesn’t matter – it’s a crucial element in making the tire grip on dry and wet roads. At Compass, we are excited to have access to some of the grippiest, yet long-wearing, rubber in the tire business. That way, we can optimize the grip of our tires in every way.

The result speaks for itself: The photo shows me cornering hard on a streaming wet road, yet I wasn’t taking any risks during that descent. There aren’t many tires I’d lean over that far in those conditions!

Why don’t cars or motorcycles use ribs to interlock with the road? They have too much power. A drifting Moto GP rider (above) would just shred those ribs. Motorbikes and cars also are heavy enough to push their tires into the road surface, where bicycles tend to skitter across the surface.

On a bicycle tire, distinct parts of the tread serve different purposes.

The center tread doesn’t matter much – you are going straight when it touches the road. This is also the only part that wears significantly, so we put some fine ribs on our Compass tires that act as wear indicators: When they become completely smooth, then your tire is at about half of its life expectancy.

Furthermore, some tests have found evidence that a very fine tread pattern can make the tire faster, because it conforms more easily to micro-irregularities of the road surface and reduces the vibrations of the bike. So it makes sense to have a fine tread in the center.

The shoulders of the tires are important for cornering traction. This is where we put our ‘file’ or ‘chevron’ tread pattern for optimum grip. There is no magic to this, and these ribs aren’t directional – the point is just to have as many as possible to hook up with the road surface, but keep them large enough that they don’t just squirm out of the way.

Finally, you have the edges of the tire, which usually don’t touch the road – bicycles simply can’t lean over as far as a Moto GP racer. Here, the tread only serves to protect the tire’s casing from rocks and other obstacles. This tread can be smooth.

It’s all quite logical, and easy to experience on the road. Then why don’t all tires have a tread pattern that is optimized for grip? I suspect it’s hard to replicate the interlocking effect in the lab. But when you ride on real roads, you’ll notice the difference!

Further reading:

Notes: (1) Aaron, M., 1988: Importance of Real-World Results. Bike Tech, October 1988, p. 5.

Posted in Testing and Tech, Tires | 7 Comments

North American Handmade Bicycle Show

Last weekend’s North American Handmade Bicycle Show (NAHBS) was a great success by all accounts. I’ve especially enjoyed the beautiful photos of John Watson (aka The Radavist) from the show. With his permission, I am reposting a few of them here.

J. P. Weigle’s bike (above) for the 2017 Concours de Machines in France was never intended as a show bike, and yet it won ‘Best Road Bike,’ ‘Best Lugged Frame’ and was the runner-up for ‘Best of Show.’

I think Peter can’t build a bike that isn’t beautiful, and even after hundreds of hard miles on two continents – not to mention very rushed Rinko-style disassembly – the bike still looked good enough to impress the judges. Congratulations, Peter!

Speaking of Rinko, Peter showed his ‘backup’ bike from the Concours in disassembled Rinko form. He reports that many visitors couldn’t figure out how a bike without couplers could become so small. I wish Natsuko could have given demonstrations of how to disassemble (and reassemble) the bike in less than 12 minutes.

Next door in what became known as ‘Rando Alley’ was Brian Chapman with his amazing and very different take on the ultimate randonneur bike. Where Peter’s Concours bike was all about function and classic aesthetics, Brian created a unique combination of black components with 1970s racer-style ‘drillium.’ True to form, it appears that he even hand-crafted custom cranks for this bike. A stunning machine!

A showpiece of a different kind was this Mosaic titanium bike – built to showcase Jpaks, a new brand of bikepacking bags. Titanium allroad bikes can be great fun, and I’d love to have a go on this one! I’ll ask Mosaic whether a Bicycle Quarterly test is on the cards.

Another bike I’d love to try is Chris Bishop’s ‘Item 4,’ a more affordable model with TIG-welded main triangle and fillet-brazed rear. Equipped with 700C x 38 mm tires, it’s a thoroughly modern road bike with a beautiful steel frame, available with rim or disc brakes. (I’d like a centerpull brake option, but that is difficult to do with a stock carbon fork.)

These are just a few of the interesting, beautiful or just plain crazy machines that were on show at NAHBS this year. Head over to www.theradavist.com for the full gallery, and then tell us in the comments which one is your favorite.

Posted in Uncategorized | 7 Comments

Bicycle Quarterly Back Issues Back in Stock

Bicycle Quarterly back issues always are popular, and a number of magazines have run out in recent months. Recently, we found a box of magazines that we had put aside in case we needed to replace copies that were lost in shipping. This means that all but two Bicycle Quarterlies (BQ 15 and BQ 18) are available again, but some editions are limited to a handful of magazines.

As you can imagine, 15 years of Bicycle Quarterly have produced some fascinating content. Below are some of my favorites:

BQ 27 has my favorite cover: It shows the winning team in the 1943 tandem taxi race: During the World War II, there was no gasoline in France (except for ‘important’ functions like the press motorcycle in the background that is covering the race), so bike racers earned a living pulling trailers as taxis.

Tandem taxis were faster, but also cost twice as much. Once a year, there was a race of the tandem taxis, where the teams used lightweight cargo trailers instead of their usual ‘taxicabs.’ When I found this photo in the René Herse archives, I knew it would make a great cover: The two racers are going all-out across the cobbles of Paris’ boulevards, while the ‘passenger’ crouches as aero as possible in the trailer, the brevet card between his teeth as he holds on during the wild ride.

The rest of the issue is just as fascinating, as it explores the roots of long-distance cycling through period documents and reports.

Another favorite is BQ 28, dedicated to the Taylor brothers (of Jack Taylor fame). Mark Lawrence spent months talking to them. He discovered a fascinating story of three ‘lads’ (and a woman) who started making bikes, went to the Paris Salon du Cycle to discover the best bike parts, raced in ‘outlaw’ races that culminated in the Tour of Britain, and saw their bikes being ridden all over the world. It’s the definitive history of this famous maker, and it shows that true stories can be as gripping as the best novels.

BQ 26 is dedicated entirely to bicycle brakes. I find brakes even more fascinating than derailleurs, and in this Bicycle Quarterly, we explore how bicycles have stopped and slowed down over time, with photos and drawings from the pen of Daniel Rebour (below). You’ll see early hydraulic brakes and disc brakes from the 1970s, which already grappled with the challenge of translating the linear pull of a brake cable into a clamping force on a disc rotor.

The sheer variety of brakes boggles the mind: Above are eight different cantilever brakes, all completely different from each other and from the standard models we know today. To date, we haven’t been able to figure out how No. 7 actually works! If you are at all interested in bicycle technology, this issue is an absolute must-read.

There have been too many fascinating stories to list more than a fraction. I enjoyed meeting the porteurs de presse, the newspaper couriers of Paris, whose annual race had them carry heavy bundles of newspapers around Paris at incredible speeds (above, from BQ 19). Or the story of Cycles Alex Singer in our very first issue. Each of these histories provide insight into an incredibly rich cycling culture, where the boundaries between racing, touring and working by bike were much more fluid than they are today.

My all-time favorite is BQ 9 with the story of ‘the Aunt,’ Paulette Porthault – nick-named, because she was the aunt of one of the young riders on the Herse team. I met her when she was in her 90s, but her memory was as sharp as ever. She told of touring all across Europe in the 1930s (above), when currency restrictions required hiding your cash in your bike’s tires before crossing from one country to another. She was an incredibly strong rider, setting times in brevets that are unbelievable today: Riding a hilly 200 km (125 miles) on a tandem in 5 1/2 hours seems almost incomprehensible.

‘The Aunt’ won the Poly de Chanteloup hillclimb race during the war. She rode in the famous post-war Concours de Machines for René Herse, where she kept an eye on young Lyli Herse, who was just a teenager, and who told me how her incredible cycling exploits were inspired by ‘the Aunt.’ Madame Porthault recounted all these adventures with incredible wit and humor. I’ll never forget my encounters with her, and I am glad that Bicycle Quarterly readers can share them. (And I am glad to report that she is still doing well, now aged almost 105.)

Paging through Bicycle Quaterly‘s back issues makes me a bit melancholic, because we’ve seen a changing of the guard over the last 15 years. Many of these inspirational people (above, Ernest Csuka of Cycles Alex Singer) no longer are with us. I am glad we’ve documented their stories so they can inspire future generations, but once these magazines are sold out, you’ll have to hunt for them in used bookstores (or online). Fortunately, Bicycle Quarterly back issues are treasured (and printed on durable, archival-quality paper), so these stories won’t be lost.

In recent years, we’ve taken this inspiration to plot our own adventures, like a trip to Japan with renowned constructeur J. P. Weigle. Seeing the experience of riding the incredible roads of the Japanese Alps through his eyes was a special treat, as was his report from last year’s Concours de Machines in France.

We now take our test bikes on real adventures, because our technical research has brought us bikes that can cover distance and terrain in a way that would have seemed impossible in the past. If you’ve missed our ride across Odarumi Pass in Japan or the search for an elusive passage across the Sawtooth Range in the Cascades (above), you’ll enjoy reading BQ‘s more recent back issues.

Most of all, the amazing stories we’ve documented will inspire your own cycling adventures. Browse the illustrated table of contents of all Bicycle Quarterlies online, or simply buy the full collection of the ‘First 50 Bicycle Quarterlies at our special price – I don’t think you’ll regret it.

Building on this great content, we can promise you many more exciting Bicycle Quarterlies in the future: We’ve unearthed some great stories that will surprise and amaze you. Subscribe today and be among the first to get the Spring 2018 Bicycle Quarterly that includes the story of Lyli Herse, a gravel adventure across the Alps from Torino to Nice, and a bike test over a snow-covered pass in Japan. Our journey continues, and we look forward to every discovery along the way!

Useful links:

Posted in Bicycle Quarterly Back Issues | 17 Comments

The North American Handmade Bicycle Show

If you are in New England this weekend, I highly recommend a visit to the North American Handmade Bicycle Show (NAHBS). From Friday until Sunday, dozens of builders from North America and beyond will show their best bikes in Hartford, CT.

This year, constructeur J. P. Weigle (above) will exhibit a number of bikes, including the superlight machine he built for last year’s Concours de Machines in France (top photo). See for yourself how he created a randonneur bike that weighs just 9.1 kg (20.0 lb) with fenders, rack, generator-powered lights and even the pump.

The Weigle is just one of the many beautiful bikes you’ll be able to see at the show. Another exhibitor is Brian Chapman, whose amazing Di2-equipped ‘Light Tourer’ (above) we tested recently. I am not sure whether he will bring the BQ test bike, but whichever creation he will bring, you can be assured it will be an amazing bike. NAHBS is definitely worth a visit!

More information:

  • NAHBS details, tickets, etc.
  • Illustrated list of Bicycle Quarterly‘s test bikes.
Posted in Uncategorized | 6 Comments

Myth 5: An Upright Position is Always More Comfortable

“Raise your handlebars, and you’ll be more comfortable.” It’s one of those almost self-evident ‘truths’ of cycling. And yet the reality is not that simple…

To celebrate 15 years of Bicycle Quarterly, we are examining 12 myths in cycling – things that we (and most others) used to believe, but which we have found to be not true. This post is about optimizing your riding position for comfort and speed.

The photo above shows me riding in a much lower position than Natsuko in the top photo, and yet we are equally comfortable on our bikes. The difference is in our effort levels: Natsuko is cyclotouring at a leisurely pace, while I am racing cyclocross.

What is important is that our positions match our power outputs. A cyclist’s upper body acts as a counterweight to the forces of pedaling. The harder we pedal, the more inclined our upper bodies should be.

That is why racing bikes have low handlebars and stretched-out positions, while on cyclotouring bikes, the bars are higher, and the riders sit more upright. The extreme are some European city bikes where the riders sit bolt-upright. On those bikes, the riders’ power output is limited, and you won’t often see them in hilly towns…

Every rider’s position changes depending on the power they put into the pedals. Above is Natsuko in a steep hairpin on Tsuchiyu Pass in Japan. Her arms are bent to lower her back as she increases her power output on the steep incline. Her low position on the bike has nothing to do with aerodynamics – it’s all about power.

My Mule is intended for cyclotouring, so it has a more upright position than my Firefly, which is designed as a racing bike.

This doesn’t mean that the Mule cannot go fast: With drop handlebars, it’s easy to adjust riding position to match power output. Getting in the drops (above) lowers my back for more power, and I can bend my arms even more if I want to go faster yet. Conveniently, this also makes me more aerodynamic, which helps when speed is my objective or when I battle a headwind.

The problem is not that a low position is uncomfortable, but that I cannot maintain the required power output for very long. What is important for comfort is that my ‘middle’ position, usually the one on the ramps of my bars, is comfortable for my average power output. That way, I can get into the drops when I need more power, or ride on the tops when going slowly.

If you always ride with the same power output, you can use simple handlebars like the ‘bullhorns’ that used to be popular on time trial bikes (above, Francesco Moser in 1984). In a flat time trial, your power output is the same for the entire ride, so you won’t need to change position.

If you ride long distances, your power output will vary quite a bit. That is why you’ll want bars that offer several distinct positions. Serge Félix (above) is climbing at maximum speed (in the drops) during the 1955 Poly de Chanteloup hillclimb race. His bike is equally at home during a 50+ hour ride in Paris-Brest-Paris. His ‘Randonneur’ handlebars have a long reach and a relatively deep drop, which give him multiple distinct postions on the bike – and the added benefit of sweeping curves that fit his hands much better than the abrupt transitions found in most ‘modern’ handlebars.

At Compass, we enjoy riding long distances with variable power outputs – working harder into a headwind and going slower when we don’t feel like pedaling hard – and so we’ve reintroduced classic handlebar shapes. Because with more positions available, you can always find the one that best matches your power output. And that is what makes your bike comfortable and efficient. It’s one of many examples of how Bicycle Quarterly‘s research has led to new Compass products that make our cycling more enjoyable.

Further reading:

Photo credit: Westside Bicycle (Photo 2); John Pierce/Photosport International (Photo 7, reprinted with permission from The Competition Bicycle).

Posted in Testing and Tech | 31 Comments

Midwinter Ride across the Tahuya Hills

In Seattle, we are lucky: We can cycle year-round. Rarely is it so cold or so icy that cycling becomes difficult. Our cycling season usually starts with the new year. “What about the rain?” you may ask. It’s not a big deal if you have the right equipment.

Last weekend was the middle of winter – halfway between the winter solstice and the spring equinox. It was a good excuse to celebrate with a bike ride. The weather forecast was for ‘showers’ – as good as it gets around here this time of the year. At least we wouldn’t get snow like we did when we ventured into the mountains last week!

Busy schedules meant that only two of the BQ Team could make it. Steve and I met at 6 a.m. to take the ferry to Bremerton. We rolled on quiet backroads through the hills to Belfair.

There we had a second breakfast – knowing that this was the last opportunity to obtain food for a few hours.

From here, we headed into the Tahuya Hills. To me, even the name sounds romantic, and the hills always live up to our expectations.

North Shore Road goes along the water of the Hood Canal, a fjord carved by the glaciers of the last ice age. On the other side are the Olympic Mountains, but on this cloudy, rainy day, we only saw glimpses of the snow-covered peaks.

It’s an amazing gravel road that winds its way in and out of the many little ravines in the mountainside.

At the same time, the road is relentlessly hilly – it was built with minimal earthworks because it wasn’t worth making big improvements for a road that sees very little traffic. This combination of attributes – minimal ‘improvements’ and little traffic – made it perfect for our ride!

It’s a course that challenged our leg power as much as our bike handling skills. The road dives into each ravine, turns sharply, and immediately heads steeply uphill again. The more speed we carried through those gravel turns, the less we had to pedal on the next hill.

Back on pavement after a few hours, we climbed high above the water, only to drop back down and roll along the shore. It was great fun.

The clouds opened briefly to hint at the views we would have enjoyed on a sunny day. We smiled at each other as we got in the aero tuck to maximize our speed on the downhill, remembering at the last second that the turn at the bottom has a wickedly decreasing radius, which caught both of us out the first time we rode it. No problem today: The low-trail geometry of my bike allowed easy midcorner adjustments of my line.

After a few hours of riding on deserted roads, we reached Seabeck on the other side of the Tahuya Hills, where we enjoyed a sandwich at the store. It had been raining on and off, and the gravel was a bit muddy, but you’d never know it from looking at our bikes. Remembering the days when we rode with plastic fenders, it never ceases to amaze me how clean and dry both rider and bike remain with a set of really good fenders. There only was a little dirt on the fork blades where the brake pads had sprayed the water they had scraped off the rims. The chain didn’t squeak, and my feet remained dry even though I didn’t wear booties.

Steve was riding his Frek, the old Trek he converted into a randonneur bike, with similar features as my bike. Neither of us even bothered putting on rain jackets, because we would have overheated on the steep climbs. Keeping the road spray off our bodies was key; our layered wool jerseys took care of the comparatively little water that was falling from the sky.

The hardest part of the ride was yet to come: the incredible Anderson Hill Road with its 14% stairstep climb. We made it up that just fine, and then we upped the pace on the last few miles back to Bremerton.

We boarded the ferry, parked our bikes, and enjoyed the scenic boat ride through the islands back to Seattle.

The Tahuya Hills course makes a beautiful 80-mile ride that goes along the water for much of the way. It sees very little traffic apart from the first and last kilometers near Bremerton. Easily accessible from downtown Seattle via a direct ferry, it’s a ride I highly recommend!

Click here for a link to the RideWithGPS route with a detailed map of the course.

Posted in Uncategorized | 33 Comments

Global Cycling Networks Video on Frame Flex

Global Cycling Networks just published a video in which they did an experiment that many of us have been talking about: Load up a frame with flex, and then release that energy. The rear wheel turns as the energy is returned to the drivetrain. It’s nice to see it in practice…

Also nice to hear: “I wonder whether frame flex is going to be the new tire pressure. Go back 10 years, and we all knew that harder tires rolled faster. And you could feel it as well. Except that now, we know that lower pressures can roll faster.”

Watch the video above, or click here to see it directly on YouTube. Enjoy!

To read our recent post about how frame flex actually can contribute to making you faster, scroll down or click here.

Posted in Uncategorized | 22 Comments