Cherry Blossoms Below, Snow Above: Cycling Tsuchiyu Touge

tsuchiyu_1500

My recovery from the accident is proceeding smoothly. My bones have healed, and I hope to ride my bike again in a few weeks. Where shall I go on that first ride? I am back in Japan, finishing the things that were left hanging when I had to return abruptly to Seattle after being hit by a car in Taiwan.

I recall a great ride up Tsuchiyu Touge (touge = pass) almost two years ago. This ride was organized for Hahn and me by friends from Tokyo. It was a day of much climbing, even more laughter, and the beginnings of wonderful friendships.

tsuchiyu_start

We were in Fukushima to visit the Nitto factory, and the following day, we set out from the lovely Onsen hotel where we spent the night. As bikes are readied, Hitoshi discovers that his tire is flat. This minor mishap does little to discourage us on this glorious morning.

tsuchiyu_ikuo_hitoshi

The climbing starts right away, and we settle into a comfortable pace. Here, Hitoshi (Vélo Après; left) and Ikuo (Cycles Grand Bois; right) lead, with Hahn and Natsuko following. Harumi (also Cycles Grand Bois) is already ahead.

tsuchiyu_postholes_1

Even though the cherry trees are in full bloom down in Fukushima, we soon encounter the first snow: We are gaining altitude quickly.

tsuchiyu_postholes_2

Along the road, we observe how the snow has melted around the trees. Different hypotheses are proposed for the cause. Is it meltwater that runs down the trunks? Or does the sun heat the dark trunks more than the white snow?

tsuchiyu_snowplow

We learn that the road has only recently been opened for traffic. In several places, we see giant snowplows parked by the road. Some have fresh snow on their blades! It rained last night in Fukushima, but here in the mountains, the rain has fallen as snow – even though it’s the middle of April, and we aren’t even half-way up the pass yet!

tsuchiyu_hairpins

The road climbs along the ridges, then breaks into tight hairpins where the hillside is too steep for a direct ascent.

tsuchiyu_motard

Even on this weekday, there is some traffic, including this “bad boy” motorcyclist. His beautifully turned-out machine includes a pristine leather bag underneath the frame. Perhaps not the most practical spot on a fenderless bike…

tsuchiyu_stop

After a picnic lunch, we stopped at a viewpoint. Several times we reach spots that seem like the top, but then we just keep climbing further.

tsuchiyu_uphill_group

Our group stays together loosely as the snowbanks on the side of the road grow taller and taller. Above 1000 m (3300 ft), the elevation is written on the road in 100 m increments. When we cross the 1500 m (4921 ft) mark, I climb atop the snowbank to take a photo (top of the post), figuring this will be the highest we’ll reach. Of course, the road continues to climb, and we soon see 1600 m written on the pavement.

tsuchiyu_top

When we finally do reach the pass, we have climbed close to 1500 m (5000 ft) since starting in the morning! The snowbanks are about 3 m (10 ft) tall, but fortunately, the road is wide enough to offer great views of the mountains.

tsuchiyu_steam

Not far away, steam rises from a peak, indicating volcanic activity that also is responsible for the many Onsen hot springs we have passed.

tsuchiyu_plain

After a second lunch at a cafeteria near the pass, we descend into a desolate landscape. Little vegetation grows here because the winds are so severe.

tsuchiyu_warning

It’s so windy that a van with a highway maintenance crew stops to warn us. The worker has to hold onto his hard hat, so it doesn’t get blown away.

tsuchiyu_ridge_downhill

With good bikes and some skill, everybody makes it across the windy parts without trouble, and then we launch into an amazing descent. Tight hairpins are joined by long straights, so we get to feel the rush of speed, before braking hard for the next turn. This continues for a while…

tsuchiyu_onsen

…until we reach the turn-off to an Onsen hot spring. It’s a surprise for us, but our companions have planned to stop here. To everybody’s disappointment, we have just missed the closing time.

DSC_5377

Undeterred, Natsuko cycles across the suspension bridge that links the Onsen with the road. We’ll never know how she persuades the staff to let us in after hours, but when she returns, it is clear that she has been successful.

After soaking in the hot water at the Onsen, we descend the final kilometers back to Fukushima. We Rinko our bikes and lock them at the station. After a nice dinner, we take the Shinkansen train back to Tokyo.

The route up Tsuchiyu Pass probably isn’t ideal to ride with newly-healed shoulders and arms, and in any case, it’ll be snowbound for a while. But just like our friends planned this beautiful trip for us, I anticipate they will find a perfect route for my first ride, and I look forward to it!

 

Posted in Rides | 14 Comments

Why slick tires don’t stick well

Compass_Bicycles_700x35

 

During the R&D of the Compass tires, I was surprised how much difference tire treads can make. I rode three sets of tires with the same casing, same tread rubber and same width, but different tread patterns:

  • standard Grand Bois Hetres with large longitudinal ribs throughout the tire tread
  • “shaved” Hetres where all tread had been removed to make “slicks”
  • prototype Compass Babyshoe Pass tires with our optimized tread pattern

I crashed on the shaved Grand Bois Hetres when the roads got wet. I made the mistake of leaning over as far as I would have on the standard tires, and found that they offered much less traction in the wet.

During my first ride on the Compass Babyshoe Pass tires with their small angled ribs, I almost hit the inside curb. The extra grip of the new tread pattern made the tires corner on a much tighter radius, for the same rider input.

It became clear that slick tires provide relatively poor grip, especially on slippery road surfaces. And large ribs squirm and thus make the bike “run wide”. Why?

batmobile_bmw

How do slick tires work on racing cars and motorbikes? Slick tires for racing cars are so soft that they form a perfect imprint of the road. They interlock with the irregularities of the road surface. This means that they don’t rely only on the coefficient of friction for grip, but also form a mechanical lock on the road surface.

The downside of the soft tires is that they wear out in just a few hundred kilometers. Often, race cars need to change tires several times during a race. And once the road gets wet, slick tires go from phenomenal to almost zero grip. Water forms a very effective lubrication layer between tire and road (“hydroplaning”).

All this isn’t optimal, but car designers have no choice: Their tires use the same surface for cornering and acceleration. Any tread pattern fine enough to interlock with the road would be ripped off the first time the driver steps on the gas. The same applies to racing motorcycles, which put down a lot of power while still leaning over as they exit corners.

motogpdrift

In fact, the more powerful racing motorbikes can be “drifted” to safely approach (and exceed) the cornering limits. This would shred any fine tread patterns.

cropped-blogheader1

Bicycles are very different. They coast around tight corners. As a result, they use different parts of the tire for cornering and for accelerating. Here is how that translates into an optimized tire tread for road bikes:

Compass_tread_pattern

Center
When the bike is going in a straight line, the tread doesn’t matter much. Cyclists don’t have enough power to spin their wheels, and bike tires are too narrow to hydroplane. There is no need to evacuate water from the road/tire interface, and deep groves like those of a car tire serve no purpose.

The center portion of a tire can be slick, but we make ours with fine longitudinal ribs as a wear indicator. Once that tread is worn smooth, you have used up about 30-40% of the tire’s lifespan.

Dots or ribs that are angled or perpendicular to the tire’s rotation might increase the rolling resistance: They have to flex as the tire rotates. Perhaps it doesn’t matter much: The center portion of the tire will eventually wear smooth and become “slick”.

Compass_Bicycles_26x2.3

Shoulders
This is where it gets interesting. The tread on the shoulders provides traction when cornering, so it’s of great importance. You spend relatively little time leaning into a turn, so this part of the tire does not wear. The shoulder tread can be designed for optimum traction without compromise. How do we get the same “interlock” as the race car slick tires?

The best solution is to provide little ridges that “catch” on the road surface irregularities and thus interlock with the road surface. One advantage compared to the slick race car tires is that the ridges cut through the water when the road is wet, thus providing the interlock even in the rain. On wet roads, the coefficient of friction between road and tire is reduced by more than 50%, so the interlock between tire tread and road surface becomes much more important.

This idea of interlock between tire tread and road irregularities is nothing new. Michelin’s engineers pointed this out in a paper in the 1980s Bicycle Science Newsletter, and even then, it wasn’t presented as something new or revolutionary.

Since the pavement aggregate is random, you want to provide as many interlocking surfaces, oriented in as many directions, as possible. By making the tread as fine as possible, you have a good chance that a rib lines up with the edge of a piece of aggregate in the pavement. That is why small ribs work best. The ribs need to be strong enough that they don’t squirm during cornering (like knobby tires do). Otherwise, you’d reduce your cornering grip again, and also increase the tire’s rolling resistance. Fortunately, the ribs don’t have to be tall, which reduces how much they can flex.

That is how you arrive at a criss-crossing pattern of fine ribs to provide a maximum of interlocking surfaces. This type of tread pattern was standard on high-performance bicycle tires for so many years, and it appears that there was good reason for this. In the old days, rubber compounds were much less evolved and provided less friction especially in wet conditions. Without the interlocking ribs, the tires would have been very dangerous in the wet. Modern rubber compounds have improved the coefficient of friction, but interlocking still is important for grip, especially in the wet.

Edges
The outermost part of the tire tread never touches the ground. You only need it to protect the tire casing from cuts. This tread can be thin and doesn’t need any pattern.

That is the logic behind the Compass tire tread. It’s not complicated, but it seems to be the only way to optimize a bike’s tire tread. We aren’t the only ones to use this type of thread. It used to be common on most high-end performance tires, and today, a number of companies still use it.

Let’s look at the alternatives:

  • Slick and coarse tire treads give up many opportunities for interlocking, and thus will offer relatively poor grip, especially in the wet.
  • “Negative” treads, that just cut grooves into the tire, apparently are inspired by car tires, where they help prevent hydroplaning. But even very wide bicycle tires are too narrow for hydroplaning (and our speeds are too low, too). Perhaps a fatbike with slick tires at 50 mph could hydroplane…
  • Knobs will squirm in corners and thus make cornering unpredictable and dangerous. (Knobs are useful for traction in mud and snow, though.)

Shirabisu_Pass

Back to the title: Slick tires are based on a simplified, incomplete understanding of tire grip. They offer less traction in dry and, especially, wet conditions.

Better tire treads exist. It’s important, because the tread pattern makes a very significant difference in how well a tire grips and performs. Being able to lean into a corner with confidence makes cycling both safer and more fun.

Click here for more information about Compass tires.

Posted in Tires | 53 Comments

Happy New Year!

happy_new_year_2016

Best wishes to you for 2016! May the new year bring you wonderful rides and great memories.

Photo credit: Natsuko Hirose

Posted in Uncategorized | 3 Comments

10 Favorite Photos from Bicycle Quarterly

Stampede_03MR

We want to celebrate a great year with our 10 favorite photos from Bicycle Quarterly.

Tom Moran’s article about fatbiking to the “Magic Bus” in Alaska was not only a great story, but it also was accompanied by great photos (above).

pbp_01MR

Paris-Brest-Paris is full of captivating images, with riders from all over the world riding through villages of old stone buildings.

breadwinner_23MR

Long before “gravel riding” became a buzzword, we already explored the Cascade Mountains off the beaten path. Above are Hahn and Theo on the road to the ghost town of Monte Cristo.

elephant_14MR

The fun of the Bicycle Quarterly Un-Meeting is captured in this photo, even if it shows only a small part of the group.

hirose_22MR

Framebuilders’ shops have a different character than bikes and landscapes, here C. S. Hirose in Tokyo.

breadwinner_04MR

Sometimes, the most exciting parts of a ride aren’t on the bike: portaging across the North Fork of the Sauk River.

hirose_35MR

“Underbiking” means riding terrain that pushes the limits of what your bike can do: Natsuko Hirose on the old road to Jikkoku Pass.

diverge_07MR

Bike tests often take us to spectacular scenery, like the aptly named “Best Road” with Mount Baker in the background…

hirose_28MR

… or to lonesome mountain passes in the Japanese Alps.

nihon_01MR

Riding doesn’t need to stop when the sun goes down: Shirabiso Pass at midnight during the Nihon Alps Super Randonnée.

What were your favorite photos or stories from this year’s Bicycle Quarterly?

Click here for more information about Bicycle Quarterly or here to subscribe.

Posted in Bicycle Quarterly Back Issues | 2 Comments

Happy Holidays!

holiday_blog

I wish all our readers Happy Holidays! I’ve enjoyed all the interactions with readers. The technical discussions are stimulating, but most of all, it’s nice to read about so many people enjoying their bikes on great rides! Thank you all!

Photo credit: Fred Blasdel

Posted in Uncategorized | 8 Comments

Why Do We Make Custom Chainring Bolts?

CranCmBoltRingDouble_1421

Recently, we received our custom René Herse chainring bolts (above). Why in the world would we go through so much trouble and expense to make custom chainring bolts?

They are pretty significant little bolts, because they are the finishing touch on the René Herse cranks. René Herse chainrings are 1 mm thicker than most chainrings. This is to make them stiffer, compensating for the small bolt circle diameter. However, modern chainring bolts are designed for thinner chainrings. They are slightly domed to make their heads deep enough for full engagement with the 5 mm Allen wrench, but their edges don’t sit flush with our René Herse chainrings.

Classic Herse cranks had flush chainring bolts. We don’t know whether the “Magician of Levallois” had custom bolts made, too, or whether bolts with a thicker, flat head were available off the shelf back then. I do suspect that he would have the “correct” bolts custom-made rather than compromise. And so that is what we did.

CranCmCrank2_A_1346

Our new bolts have a flat surface and sit flush with our chainrings. It’s a small detail, but to us, it’s important. As custodians of the René Herse name, we have to strive for perfection…

We also offer the new bolts separately. That way, customers who bought their Herse cranks with the “domed” bolts can upgrade their cranks to the Herse bolts. The new bolts also are useful for restorations of René Herse bikes.

Click here for more information about René Herse cranks and chainring bolts.

Posted in Rene Herse cranks | 11 Comments

Rinko Parts – Useful not only for Train Travel

RinkoDemo__1161

Since our first visit to Japan last year, we’ve been fascinated by Rinko, the Japanese system of packing bikes for train travel. The Rinko system developed by the builders Alps and Hirose is especially elegant and results in the smallest possible package for the bike.

It still amazes me that a fully equipped randonneur bike, with a 60 cm frame, fenders, racks and generator-powered lights, can be disassembled in 12 minutes into a package that is no larger than the frame. Drape a bag over it, and you can carry it on trains, buses, and subways, or load it into even the smallest economy car. Put it in a padded bag, and you can travel on many airlines without paying extra fees. Best of all, there are no couplers or other parts that add significant cost, complication and weight.

BagsOsCover_1049

After building my own Rinko bike, the “Mule” (above), I realized that every bike could benefit from being Rinko-compatible, even if only to remove the rear section of the rear fender when you transport a the bike inside a car…

The Winter 2015 Bicycle Quarterly includes a photo feature showing the details that make a bike Rinko-compatible. Small things make it easy to disassemble your bike. For example, slotted cable stops that allow you to remove the handlebars with the brake cables attached. There are only a few special parts needed to make a Rinko bike, and Compass Bicycles now offers them.

Rinko_nut_fender

A key part is the “Rinko nut” (visible at the top of the fender). The rear fender is cut in half, a piece of fender is inserted into the rear portion, and the Rinko nut allows you to secure the two halves after you have slid them together.

A constructeur will cut the tongue that joins the two fenders from a third fender (since they can use that fender to make tongues for multiple bikes), but you can also shorten the bike’s rear fender by a few inches to get the material you need. Preparing a hammered fender so its halves slide together smoothly isn’t easy, so most Japanese builders use smooth fenders on their Rinko bikes.

FendCmRinko_3419The Rinko nut is threaded on the outside, so you can attach it to the fender with the supplied (thin) hex nut. It also is threaded on the inside. This is where the bolt goes that holds the two fender halves together. It’s a simple part, but if you have to machine it yourself, you’ll spend some time. So we had a batch made to save you the trouble.

BagsOsCoverLo_1820

A part that is useful not just for Rinko are the Ostrich tube covers. These pads wrap around your frame’s tubes to protect them during travel. The pads are thin, so they can be carried in a handlebar bag when not in use. They close around the frame with Velcro.

The “long” version (above) measures 450 mm, while the “short” version is 240 mm long. The pads fit around standard and slightly oversize frames, but they are not large enough for extremely oversize tubes.

rinko_pedal

Rinko pedals aren’t required for travel, but they make disassembling your bike much easier. The stub remains on the cranks, and the pedal can be removed without tools. Available as clipless (above) and platform versions (below). The models we sell have MKS’ super-smooth bearings that are nicer than any other currently-made pedal I have tried.

PedlMkPlaRi_1576

These pedals are useful not only for Rinko, but also for bikes with S&S couplers, or if you want to switch between platform and clipless pedals on the same bike. (If you just want super-nice pedals with great bearings, these pedals also are available in standard, non-Rinko versions.)

BrakCmRinko

The Compass Rinko brake is functionally the same as the standard Compass centerpull brake, but one arm has a different shape, so that the straddle cable unhooks on both sides. That way, you can remove the handlebars and brake cables as a unit. (With the standard centerpull brakes, one end of the straddle cable attaches to the brake.)

brake_cable_rinko

The special straddle cable has two barrels that hook onto the brake arms. The cable comes with a second end that gets silver-brazed onto the wire (arrow). That way, builders can set the straddle cable height as they like, for example, to clear a taillight. A minor disadvantage of the Rinko model: After wheel changes, you have to hook both ends of the straddle cable back onto the brake (rather than just one end).

ToolHiRinko

The Rinko Headset Tool is shown here on the headset locknut. It looks like a cat, is made from lightweight aluminum, and weighs just 14 g. You can tighten your headset by hand, or use an 8 mm Allen wrench for extra leverage (above). The other socket measures 10 mm. This tool also is useful if you want to take a headset tool on a ride or tour, where the 8 and 10 mm sockets also can come in handy.

BagsOsL100_

Rinko bags are used to cover the Rinko bike package during travel. The carrying strap attaches to the bike frame, so the bag doesn’t have to carry the weight of the bike (see photo at the top of the post).

The Ostrich L-100 (above) is designed for the Alps/Hirose system of Rinko. Made from sturdy materials, it weighs 310 g, yet when not in use it fits into a pouch that is the size of a small water bottle.

BagsOsSL100

The Ostrich SL-100 has the same dimensions as the L-100, but it’s made from ultralight SilNylon. It weighs just 200 g and packs very small. The SL-100 is not as strong as the standard L-100 bag, so it is not recommended for “Rinko beginners” who may try to stuff their bike into the bag, rather than just pull the bag over the Rinko’ed bike package.

rinko_40

Both Rinko bags come with three straps for packing the bike, a shoulder strap and a pouch to carry the Rinko bag on your bike. (SL-100 shown above.)

rinko_41

The Ostrich OS-500 Airplane Bag is padded for air travel. It is designed to work with many Rinko systems, so it is significantly larger than the L-100 and SL-100 bags. The Rinko’ed Mule fits into the OS-500 bag with room to spare. Taping the bag to reduce its volume allowed it to meet the luggage requirements for All-Nippon Airways (ANA) without requiring a surcharge.

rinko_bags

Now that I have enjoyed travel with a Rinko bike, I don’t want to be without one. Considering how little it takes to make a custom bike Rinko-compatible, I know that from now, all my new bikes will be ready for Rinko. Being able to take my bike almost anywhere opens great possibilities.

Click here for more information about Rinko parts from Compass Bicycles Ltd.

Click here for information about the Winter 2015 Bicycle Quarterly with a detailed article on how to design a bike to be Rinko-compatible.

Posted in Product News, Rinko | 54 Comments