Thursday, April 5, 2012

A Brief History of Pavé

Inspired by recent Tweets, we ponder to ourselves, from where do pavé blocks come from? How did these cobblestone sections come about?

Pavés of the Arenberg trench, likely made from sandstone.
Our first stop is obviously Wikipedia, where we learned that the term "cobblestone" is idiomatic. The root English word is "cob" which means "rounded". Thus "cobbles" roughly means "rounded lumps" or "large pebbles".

Indeed, back before the days of automobiles and carbon fibre bicycles, the fastest means of land transport is by horseback. The rounded shape optimized the speed of propulsion by means of a horses' hooves, and they were found to be quite sturdy in all sorts of weather even if they noisy and not the most comfortable for carriage-riding.

Wikipedia photo by Aaron Logan, permission CC-BY-3.0.
As carriage travel becomes more commonplace in the 19th century, these cobblestones were replaced by setts: basically the rectangular stones that we today still often refer to as "cobbles". In turn, the use of macadame and asphalt started in the 20th century as automobile travel became more commonplace.

As we discussed in our historical series regarding the Ardénnes classics and what we know today as the cobbled classics, if we had traveled in time to the early 20th century we would notice little difference in the road surface between the two types. But as time progresses, each race preserves (or adds) to its challenge by either adding more hills in case of Liège-Bastogne-Liège, or by preserving as much of its cobbled sections as in the case of Paris-Roubaix and Ronde van Vlaanderen.

Unlike in English where strictly speaking a cobblestone should be round and a sett should be square, in Flemish/Dutch there is only one word to describe both, that is "kasei". It is derived from the latin word "calceata" which means "stone-covered road". These stones are lovingly also called "kinderkopjes" or "childrens' heads". A rider who is considered good in riding over kasei is called a "kasseienvreters" or "stone-eater".

Kasei can be made from a variety of materials, including granite, sandstone, limestone, porphyr. Local availability has much to do with what is used at different parts of the low countries. We consulted our resident geologist who got busy and produced the following surficial geological map of the Paris-Roubaix route.

Surficial geology of the Roubaix area, produced using InfoTerre.
According to our resident geologist, the area around the Trench of Arenberg is mostly marine sandstone ("glauconitic"), with chalk limestone to the north as we approach Roubaix. Since the software uses the French geological database, the map above shows only the French side of the border.

Centrum Ronde van Vlaanderen's Reference

So where do the pavés featured on the classics races come from? To answer this, we consider the types of stones used in their construction. Fortunately for us, the Ronde van Vlaanderen Museum has a nice display of different types of stones that we can use as reference.

A pavé ride simulator at the Ronde van Vlaanderen Museum.

Porfier or porphyry is an igneous rock texture that means that you have big crystals in a finer-grained matrix. It is the only magmatic rock found in Belgium, where they are quarried in Quenast and Lessines, usually with a grey speckled hue. They are very hardy and can last up to 300 years!

Porfier stones.
If you really want to see where these stones come from, the quarries are clearly visible on Google Maps links above.


Next we have sandstones from the Mur de Grammont. The caption says they are less durable and more porous. In addition, they are susceptible to splitting and cracking. The Belgian ones probably from the Devonian age quarries in the Ardennes ("psammite"). The French ones probably come from quarries in Artois, famous for blue-ish sandstones that are as hard as granite from the Vosges, even if they are still somewhat brittle and susceptible to splitting and cracking depending on how well-cemented they are.

Holy stones from the Muur de Grammont, made from sandstone.
Thus, according to our resident geologist, the Holy Trench of Arenberg and the Holy Wall of Grammont share the same type of material.


Unlike what many thought, granite is the newest material and possibly the least common. They are imported from Sweden and Norway only starting in the second half of the 20th century. They are very sturdy compared to porphyr and sandstone.

At this time it is not clear to us whether they will replace all stones on the course of the races. The reason for this is that the hellingen or cobbled sections used in races are considered a national treasure both in France and in Belgium. Thus, effort to preserve them may include using the original material.


Fortunately for us fans of cobbled (or setted) races, there is significant effort for preservation of these cobbled roads both in France and in Belgium. Especially for Paris-Roubaix, the organization Les Amis de Paris-Roubaix (Friends of Paris-Roubaix) works all year long to restore and preserve the famous cobbles of northern France. Membership confers honor AND a small pavé trophy. Podium de Café has a very nice interview with the organization that you should read here.

There you have it, a brief history of pavé! 

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