Suspension Losses Confirmed

RumbleStrip

Recently, Bicycle Quarterly’s experiments on suspension losses have been replicated and confirmed: Higher tire pressures don’t result in faster speeds – even on smooth pavement. Replicating results is a crucial part of science, which makes the new results an important milestone in the understanding of bicycle performance. No longer is it just Bicycle Quarterly talking about suspension losses and lower tire pressures – the science is becoming widely accepted.

When Bicycle Quarterly’s tire tests (below) showed that higher pressure didn’t make your tires faster, few people believed it. Back in 2007, everybody “knew” that pumping up your tires harder made them faster.

We had doubts, too. So we tested again and again, and our results always were the same. We concluded that it was true, even if it went against the accepted wisdom of almost 100 years of cycling knowledge.

MarkTiretesting

Looking through the literature and talking to experts like Jim Papadopoulos, we found a mechanism that could explain this: suspension losses caused by vibrations. As the tissues in the rider’s body rub against each other, friction turns energy into heat. And that energy must come from somewhere: It is taken from the forward momentum of the bike. Your body vibrates, and that slows down the bike. (The bike also vibrates, but it’s not as significant, since it’s mostly made from hard materials that don’t generate much friction.)

The next step was to prove that these vibrations could cost significant power. We went to rumble strips on the shoulder of a highway (photo at the top), because they allowed side-by-side comparison between smooth pavement and a “standardized” rough surface. The results were surprising: Riding on the rough surface took up to 290 Watts more than riding on the smooth surface (below).

BQ8-1_chart

Where did those 290 Watts go? After testing various pieces of equipment on the rumble strips all day, I knew where the energy went: My body was sore all over. I had experienced suspension losses on my own body!

Careful testing is only a first step. Real science demands that all scientific experiments are repeatable and replicable.

Repeatable means that if you run the same experiment twice, you must get the same result. We did that multiple times: Each configuration was run at least three times. And we ran the same equipment at the beginning, in the middle and at the end of the test, to make sure that conditions (wind, temperature, etc.) did not change and affect the results.

Replicable means that others must be able to do the same experiment, and get the same results. We published our methodology for testing suspension losses in Bicycle Quarterly. That was back in 2009, and we’ve been waiting for others to replicate them. We are excited that now Joshua Poertner has done similar test, also using rumble strips. And his results are similar to ours:

rumble strip test web

The blue line at the bottom shows the old-style steel drum tests: Higher pressure makes your tires faster. But that is true only if you don’t have a rider on board. (No rider = few suspension losses)

Once you put a rider on the bike, things start to look very different: The green line shows brand-new asphalt, the yellow line coarse intermediate asphalt, and the red line are the rumble strips. You can see that resistance increases beyond a certain pressure. This is the opposite of the old wisdom, which is expressed by the blue line.

It’s important to remember that the green, yellow and red lines are real-world testing. The blue line is done in the laboratory. And when laboratory tests don’t match the real world, then they are useless.

track_tire_test

The article doesn’t mention Joshua Poertner’s methodology. I am a bit surprised that the dropoff in performance at higher pressures is so large. Our own testing (above) – on very smooth pavement – showed that very high pressures actually resulted in the same performance as lower pressures – not worse performance, as Joshua Poertner’s data seem to indicate. In the future, we’ll have to figure out which is correct. Or perhaps it’s a simple matter of Joshua Poertner’s “smooth” asphalt being rougher than ours…

However, everybody now agrees that higher pressures do not make you faster. We also agree that when things get rough, higher pressures are actually slower.

For riders, what matters most is how you can make your bike faster. And Joshua Poertner’s advice mirrors what we’ve been saying for years: “It turns out that it’s much better to be 10 or even 20 psi lower than the ideal tire pressure than 10 psi higher.” And: “Here’s the next thing you have to think about. As tire width increases, tire pressure decreases. So a wider tire performs better in terms of rolling performance.”

tire_test

Looking into the future, Poertner said: “I remember when wheels went from 19 mm to 23 mm. It was a very gradual process. And then we went from 23 mm to 25 mm. Now we’re seeing 28 mm wheels. Where does it stop? I don’t know.”

And we all agree that wider tires are faster because they can run at lower pressures over a mix of surfaces. Joshua Poertner is comparing identical tires at different widths. It is understood that to offer good performance, the wider tires must be supple, otherwise, you lose too much energy to flexing the tire casing at it deforms with each wheel revolution.

In other words: On most roads, and especially on rough ones, a 32 mm Compass tire will be faster than a 26 mm Compass tire. But a 42 mm Schwalbe Marathon will be slower than both, even though it’s wider – because it’s so stiff that its casing absorbs way more energy.

Here is what it means in practical terms:

  • Run the widest tire that fits your frame, at least within reason. Bicycle Quarterly’s tests have shown that 32 mm tires roll as fast as 25 mm even on very smooth asphalt, and faster than 23 mm or 20 mm. On rough roads, the wider tires are clearly faster. Since we measured this at 22 mph (35 km/h) with a rider, this takes into account the wind resistance at typical “spirited” cycling speeds.
  • Run your tires at a relatively low pressure that still offers good handling. You don’t want your tires collapse under hard cornering, but beyond that, there is no benefit to adding more air. Experiment with different pressures, but don’t be afraid to let out some air.
  • Select the most supple tire for the best performance.

It’s taken almost a decade, but it’s nice that our results finally have been replicated and confirmed. What once was controversial is becoming universally accepted. And as Joshua Poertner points out (“Where does it stop?”), there is more research to be done. Fortunately, Bicycle Quarterly is already working on this!

Further reading:

Posted in Testing and Tech | 80 Comments

Another Road for the Collection

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A few years ago, I wrote in Bicycle Quarterly how I collect roads. Others collect bikes, or rare components, or photos of racers. My collection is more esoteric: I collect roads. Not the physical roads, but the experience of riding on them. Like all collectors, I have criteria of which roads are worthy for inclusion in my collection, and which are merely conveyances that transport me where I want to go.

During the recent Golden Week cyclotouring trip, I was excited to add another road to my collection: Road 327 near Matsumoto in Japan. I explored this incredible road during a solo early-morning ride. And I don’t regret getting up at 5 a.m. to ride it.

valley_in_the_distance

The previous night, I had seen a valley in the distance, leading up to snow-covered peaks. If a road went up there, it could be spectacular. It seemed worth exploring…

A quick lock on Google Maps showed a promising road up the valley. The road dead-ends at an onsen hot springs high up in the mountains. “Dead-end” means little traffic… “High in the mountains” promises great climbs and descents.

hairpins

The next morning, I headed out before breakfast. And the road fully lived up to my expectations.

hairpin_road

The climb started with a set of amazing hairpin turns. The map and photo above show that first part of the road. The road wasn’t so steep that I was struggling, and it was fun to push myself on this stretch. I gained elevation quickly. Looking back, I could see several levels of the road below me.

cliffside

cliffside_road

The next section was more open as it ran along a steep cliff.  This part offered great views of the valley below and of the mountains ahead.

waterfall

I rode past waterfalls and across little bridges, even traversed a short tunnel.

creek

The entire time, I saw no more than three or four cars, as well as a very short tour bus. Its driver clearly had driven this road many times, as he took very confident lines around the tight turns.

pass

After an hour of climbing, I reached a small pass and realized that it was time to return, if I wanted to eat breakfast. Later, checking the maps, I realized that I had climbed 800 m (2500 ft) in just 14 km (8 miles). The maps also show that the road continues for another 3 km, with another 250 m of elevation gain. I’ll have to come back!

descent

The descent was even more fun than the climb. I quickly gained speed on the wide-open stretches. My brakes got a workout as I approached the tight hairpin turns at high speed. As I leaned the bike hard, I could feel my wide, supple tires bite into the pavement. It’s nice to get feedback that there is grip in reserve.

The best part of the downhill was the section along the cliffside. With hardly any braking, I threw the bike right, left, right again. Japanese mountain roads have useful mirrors that allow you to see around the corners: It’s important to make sure that there is no oncoming traffic when you take the best line on a single-lane road!

In twisty sections like that, I appreciate a bike that handles with precision and corners without reluctance. Descents like these are the reason we spent so much time studying front-end geometry, think endlessly about bike handling, and optimize tire construction. On this empty road, nobody could see the smile on my face, but it was huge.

And I made it back for breakfast (almost) on time.

Further reading:

Posted in Rides | 8 Comments

Look-Compatible MKS US-L Pedals

Compass bicycles_5982 copy

Looking for LOOK-compatible pedals for your travel bike? Here is the solution. The MKS US-L pedal uses a similar retention system as the LOOK Keo. In fact, the cleats are interchangeable. Unlike any other LOOK-compatible pedal, the MKS US-L is available with the EZ-Superior Rinko system.

Like all MKS pedals we sell, the US-L is a top-of-the-line pedal with ultra-smooth cartridge bearings. You really have to turn the spindle with your fingers to believe how smooth these pedals spin. And they still spin smoothly after years of use…

rinko_pedal

That system works similar to an air hose coupling: The part on the left remains screwed into the crank. Turn and push the outer ring, and you can remove the pedal. No tools required, and it only takes a few seconds.

The photo above shows the US-B Nuevo pedal, which is compatible with the Time Atac retention system. The Rinko system is the same on all MKS pedals in the Compass program.This has the added benefit of making it easy to swap pedals: for example, if you want to ride the same bike with platform pedals during commutes, but with clipless pedals during spirited weekend rides.

Compass bicycles_5970 copy

All MKS Rinko pedals come with a neat bag to carry your pedals while traveling.

Compass bicycles_5999 copy

The MKS US-L pedals also are available in a standard, non-Rinko version. The release tension is adjustable with a 3 mm Allen wrench (included) in three steps. This makes it easy to match the tension between right and left pedal.

The retention system is split, so that only one side has to open to release the shoe. This means that the release is relatively easy – you only have to overcome half the spring tension that holds the shoe when pedaling. No longer do you have to choose between safety during all-out pedaling efforts, and safety when stopping!

Click here for more information about MKS pedals.

Posted in Pedals | 22 Comments

Golden Week Cycling

tunnel

Golden Week is one of the biggest vacation times in Japan. It’s a combination of one-day holidays that result in a little over a week of time off. And it’s springtime, so virtually every cyclist takes to the road. This year, we went on a ride in the Japanese Alps with a group of friends.

rice_field_cyclists

Spring in Japan is a great time for cycling. It’s warm, but not yet hot. The skies are blue, and the fresh green of the forests looks especially vivid in the bright sunlight. The rice fields are being flooded. It’s the Japan you imagine in children’s picture books.

avalanche_gallery

The best roads of Japan go through the mountains, and this pass was especially spectacular. The cliffs were so steep and loose that the road was built into the mountain, with avalanche galleries protecting it from falling rocks (and snow in the winter). At the top, we exited a tunnel to see a spectacular view of the Japanese Alps (top photo).

mule_mountains

This area really deserves the name “Japanese Alps”, as the steep mountains and broad valleys look remarkably similar to Switzerland. So do the small fields, and even the ski slopes.

lakeside_cyclists

We cycled on tiny roads past bucolic lakes.

mountain_road

The roads rarely were flat, which made the cycling more interesting.

lookout

The pace was unhurried, with plenty of time for exploring…

shrine

… visiting local shrines…

soba_farm

…and even a farm where wasabi (Japanese horseradish) is grown in the shade of a little valley.

dirt_path

We avoided large roads as much as possible, preferring little byways and even dirt paths.

matsumoto_castle

Our ride ended in Matsumoto with its magnificent castle.

rinko_matsumoto

After some more sightseeing, we Rinko’d our bikes and returned to Tokyo. Thank you to our friends for organizing this great trip!

Photo credit: Natsuko Hirose (top photo).

Posted in Rides, Rinko | 10 Comments

Compass 31.8 mm Randonneur Handlebars

Compass Randonneur Bars 31.8 Clamp

We are glad to offer our Compass Randonneur handlebars with a clamp diameter of 31.8 mm (for modern stems), in addition to the 25.4 mm model we introduced last year.

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These handlebars have been very popular, and for good reasons. They support the rider’s hands much better than conventional handlebars. Having ridden them (and the 1940s Mavic/AVA bars on which these are modeled) in two Paris-Brest-Paris, a 24-hour Flèche, and on numerous tours, they are by far my favorite handlebars.

square_bar

Unfortunately, too many modern handlebars have a very short reach and a very square shape (above), which locks you into just three hand positions. After a few hours of riding, these bars often feel uncomfortable, and during longer rides, you can even suffer from nerve damage.

Compass Randonneur Bars 31.8 Clamp

The generous curves of Compass handlebars allow you to find the perfect hand position on a continuum: Moving your hands slightly in- or outward will also change your wrist angle. And, of course, you can change your hand position during the ride.

We now offer both Compass handlebars for modern 31.8 mm stems: The Randonneur (above) has an upward sweep that provides a curves that supports the cupped palm of your hand perfectly.

Compass Maes Parallel 31.8

The Maes Parallel (above) offers flat ramps and generous space to roam as you ride. (Both models are also available in a 25.4 mm diameter. For 26.0 mm stems, we offer a shim that increases the diameter for a perfect fit.)

Click here for more information about our handlebars.

 

Posted in Handlebars | 28 Comments

Summer 2016 Bicycle Quarterly

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When our readers receive the Summer 2016 Bicycle Quarterly, they’ll have a hard time putting it down. We embarked on our most ambitious adventure to date: A ride from Cholula to Mexico City via the 4000 m (13,100 ft)-high Paso de Cortés. We rode on rough gravel roads, past the majestic volcanoes of Popocatepetl and Iztacchihuatl, before testing our bikes’ handling on a super-steep and twisty paved descent. Then we took the old road to Mexico City, riding on century-old cobblestones.

firefly_rest_izta

A ride like that isn’t possible on ordinary bikes… We brought our latest test bike, a Firefly titanium Enduro Allroad bike that promises the performance of a modern racing bike with the wide tires we needed for the loose gravel on the actual pass. For comparison, we brought an old Bontrager Race Lite that Hahn had converted into an Enduro Allroad bike. In the best Bicycle Quarterly tradition, this ride was part adventure and part bike test. Both bikes are featured in this issue.

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The ride took us deep into the history of Mexico: We retraced the steps of Hernan Cortés, who marched on the capital of the Aztec empire. But instead of bloody conquest, we came to celebrate how bicycles have played a major part in the rejuvenation of Mexico City. In a second story from this trip, join us as we explore this fascinating metropolis by bike.

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Suntour: No other defunct component maker is missed as much as this iconic Japanese brand. Takayuki Nishiyama has researched Suntour’s history, with access to original archives and interviews with key players, including long-time Suntour president Junzo Kawai. Learn how Kawai’s dream of better sports bicycles led to the slant parallelogram derailleur and many other innovations.

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There are many framebuilding classes all over the world, but the Tokyo College of Cycle Design is the only place we know that offers a 3-year degree in bicycle building. We visit this remarkable school and show you the students’ work.

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Bike rides don’t have to push the limits to be memorable. Natsuko Hirose takes you on two rides to Hokkaido. She first went there as a student with a group of friends. With no experience and little money, every day was an adventure. More than a decade later, she returned for a more leisurely trip of onsen hot springs, good food, and riding up mountain passes.

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Many of the latest trends are not as new as we think. We explore the origins of wide, supple tires with photos of a 1920s survivor. Now that suitable tires are available once more, this machine has been returned to the road. How does it ride?

Chainline5spd3XOur technical feature looks at chainline. Chainlines have changed in recent years, with cranks moving further outward, and rear cassettes extending further inward. Why does it matter, and how does it affect your riding experience? We’ve measured and tested to bring you answers. This knowledge will help you set up your bike for optimum performance.

As always, there is much more in this issue of Bicycle Quarterly: Our Skill column talks about how to brake on all kinds of surfaces. Our Icon article features a superlight bell, and there is much, much more…

Subscribe today to receive your copy of the Summer 2016 Bicycle Quarterly without delay.

Posted in Bicycle Quarterly Back Issues | Tagged | 15 Comments

The Paso de Cortés

not_for_publication

Where is the best place to test an Enduro Allroad bike? That is what we asked ourselves as we planned the Summer 2016 Bicycle Quarterly. It had to be a ride that went beyond the capabilities of the Allroad bikes we usually ride, with their 42 mm-wide tires. And yet we couldn’t just take it to a mountain trail, because the Enduro Allroad bike still is a road bike…

paso_uphill_turn

We found the perfect road in Mexico. The Paso de Cortés is one of the highest passes in North America. The uphill is made from very soft gravel, perfect to test whether 54 mm tires are wide enough to float over loose surfaces rather than sink into them.

paso_de_cortes

After climbing to an elevation of 4000 m (13,100 ft), we launched into a paved downhill with dozens of challenging turns. It was one of the best descents I’ve ridden anywhere in the world, and that includes the incredible Shirabiso Pass in Japan…

hahn_corner

This rollercoaster ride would challenge any bike’s handling. How does a 54 mm tire feel on pavement? There is only one way to find out!

popocatepetl

It was a ride that pushed the limits of our endurance. After 12 hours on the bike, you notice whether your bike performs well or not!

hahn_and_sheep

Our ride took us deep into Mexico, with its beautiful mountains and fascinating history. We explored a country that isn’t known as a cycling destination, yet we found wonderful riding and amazing landscapes. Riding over the Paso de Cortés was our greatest adventure yet! The full story and bike tests will be published in the Summer 2016 Bicycle Quarterly, which is going to print today.

Subscribe to receive the Summer issue without delay.

Posted in Bicycle Quarterly Back Issues, Rides, Testing and Tech | Tagged | 7 Comments