The aerodynamics of the last century

In a world where bikes are getting more and more aerodynamic as a result of the research for the marginal gains within the UCI rules, it's interesting to reflect on the times where the UCI wasn't the rigid law it is nowadays. So in this page I hope to try to make a concise history of the "lopro", "funny bike", "chrono", "plongeant" track and time-trial bikes of the 1980s and 1990s. I don't plan on listing them all but I want to expand on when they came to be, how they came to be, what they tried to achieve and how, how they evolved and finally when they stopped existing. I will also list a few of the popular exemples, and odities that pushed the innovation at the time.

The quoted terms are not all mutually exclusive but they do mean different things. Lopro bikes are simply bikes with a top tube that slopes downwards towards the headtube. Funny bikes are bikes with a smaller wheel in the front. Chrono is an abbreviation of "Vélo de Chronomètre" aka a time-trial bike. And finally "plongeant" is the french word for diving, it's similar to lopro in definition. For the purpose of simplification, I'm going to flatten most of the differences and put them all in the same basket as they were used for the same purposes. If differences are notable, they will be mentioned.

When did this happen and why did it happen

I believe the when and the why of how low-profile came to be are closely related to one event in 1972. On the 25th of October 1972, Eddy Merckx rode 49,431km in an hour. Before that and for the majority of the post-war period of cycling, the gains were sought in the form of lightening the bikes. Aerodynamic bikes existed before, but they were just proof of concept rather than competitive options. One of the most striking exemples is Cristoforo Gazzoni's wooden and canva fairings bicycle. It dates back to the 60s at the latest and features fairings around a classical frame to make it more aerodynamic. Another good exemple is seen in an interview of Ernesto Colnago on his most iconic bikes : a prototype made for the hour record in 1968. The principles of what would drive the aerodynamic search were already here : fairings would allow the bike to cut the air more efficiently and the geometry was such that the rider would lean onto the front of the bike, reducing frontal area and again facilitating penetration in the air.

But going back to the hour record of 1972, I think it's important to talk about this event because the bike used embodies much of the Zeitgeist at the time and the event itself was so important that there is a distinctive before and after. A lot of the information on the specific bike Merckx rode is confusing, conflicting or speculative but past the details we can keep in mind the following. Eddy Merckx rode a purpose-built Colnago frame made out of very thin tubing with lightened components. The takeaway being that the bike and every single one of its components were thought to be the lightest possible. It came out to a 5,75~5,9kg bike at a time where most road race framesets were already close to half of that when completely naked.

Merckx being, even at the time, considered the ultimate athlete in the sport and weight being a finite improvement (before running into rigidity issues), innovation was pushed by smaller framemakers. Exemples are few and far as it was still a transitional phase : not everyone believed aerodynamics were the path to follow. Use in competition was very scarce and documentation about them is even more scarce.

Around 1976, Tony Maier-Moussa, at the time bike mechanic and soon-to-be-successful Assos founder, was getting inspired by ski jumpers to make skinsuits and eventually rethink the position of riders on their bike. He imported carbon to create his own frame with drop-shaped tubing and with handlebars mounted on the fork crown. It was used in the 1978 track world championships. . Maier-Moussa acknoledges an important point in this interview :

[The wind tunnel tests were] fantastic. Until I asked Daniel Gisiger to get on the bike... With the cyclist, we measured almost no improvement. What a disappointment!

As an observer, I can notice two points as to why this might have been the case : first of all both wheels are 700c and the frame looks to have a run of the mill race geometry of the time. So despite the agressive looking bike with fork-crown-mounted bullhorns, I would wager that the position would be close to identical to someone riding in the drops of a road bike of the time.

According to Claude Genzling and Bernard Hinault, the first studies that had bike AND position of cyclist in mind came soon after.

The first studies aimed at reducing the aerodynamic drag of bicycles and optimising that of the man-machine combination according to the rider's position were undertaken in 1977 by Maurice Ménard, director of the Aerotechnical Institute of Saint-Cyr-l'École and professor at the Conservatoire National des Arts et Métiers. This initially resulted in the Profile bicycle, which was tested during the 1979 Tour de France, followed by the Delta bicycle, which Laurent Fignon used in the 1984 Tour de France time trial stages.

The Gitane Profile was a profiled road bike, and therefore doesn't necessarily fit in our history of time-trial bikes but I think it's important because it was used at the top of the sport at the time and as a time-trial bike. The prominent features were the profiled tubing, the deep wheels, the back mounted front fork and the dropping handlebars.

Koichi Yamaguchi, at the time an apprentice at 3Rensho under the supervision of Yoshi Konno, recalls toying with the idea of aerodynamics in 1977 :

Attention to long fork (this bike use 700x700 wheels). Idea is long fork makes air go through between blades not blocking air flow. 2nd this makes head tube shorter. We try to design small front triangle to save weight and gain rigidity. This frame tubing is Isiwata 015 Very thin wall ultra light weight tubing. (light weight but bit flex much) 3rd we can inset stem from bottom of crown to make a Takhion style set up. 

While not explicitly being a lopro bike, I think it's important to note the aspects noted in the quote, namely the small headtube and the ability to make a Takhion style setup.

Establishing a new standard (1980-1984)

It's at the 1980 Olympic games in Moscow that came the first great recognition of this type of bike. The team time-trial was won by the Soviet Union on the Colnago Mexico TT/Aerodynamica. The Colnago was shyly aerodynamic but still featured parts or ideas that would be consistently used throughout the period. The more obvious being the front wheel being smaller.

Recognition also came at the same Olympic games with the win of Lothar Thoms in the 1000m men's individual pursuit. Not much information is available about the bike but what is known is that it was most likely a Textima which is very reminiscent of later bikes. Textima was a gigantic East German textile factory so big that a part of it was making bikes under the MIFA and Diamant monikers. But within this bike factory, was the institute behind the high-level bikes created for the East German athletes of the time. The prominent member of this laboratory was Paul Rinkowski. He died in 1986 but Textima, later FES, lived on and propelled German bikes on the forefront of technology.

On the 19th of January 1984, Francesco Moser blew the record out of the water with an hour record of 50,808km. As the story goes, unsatisfied with the record, he promised to come back in 4 days to beat it again. And so, on the 23th of January 1984, Moser rode 51,151km.

Notable Exemples

This is the section where I detail the specific bikes I mentioned in the article. I didn't want to include it in the main text because I thought it would be too heavy, regardless, the bikes mentioned are clickable to bring you to here, so you can go back and forth if you want.

Eddy Merckx's Colnago (1972)

Eddy Merckx rode a purpose-built Colnago frame made out of double-butted tubing (0,7/0,4/0,7). Most of the componens were purpose-built with exotic alloys. According to Ernesto Colnago himself, the stem and spokes were made out of titanium, hubs were made out of beryllium and most of the other components were drilled/milled : handlebars, headset, crankset, chainring, chain, seatpost and possible more. The seatpost and headset were also made out of an unknown alloy. Or a combination of all of the above.

Gitane Profile (1979)

The Gitane Profile was a result of the aerodynamic studies that came out of the Aerotechnical Institute. It first came out to be for the 1979 Tour de France for the Gitane-Campagnolo-Renault team featuring Bernard Hinault. With this out of the way, there were different versions of this bike/model but I will focus on this bike specifically. The frame was made out of profiled Reynolds 531 tubing. It had a gusset going from the top to the bottom of the headtube, extending inbetween the top tube and the downtube but also between the head tube and the downtube. This is note worthy because not many bikes with gussets had this specific part covered, in fact only a few exemples of this bike had this specific aspect to it. The tubing was profiled as mentioned, but the top tube remained round. The seat tube was also dented inwards to allow the back wheel to be scooted forward, to make the bike shorter overall. Apart from that, it did a few different things to be more aerodynamic : the front brake was directly between the fork and the downtube. I think the most important part may have been the drooping and forward-curved handlebars made by Mavic.

Later versions didn't have the indented seat tube, didn't have a round top tube and featured different tubing. Moreover, the version mentioned was made for time-trial when other version were made for road racing. As with the Laser concept, the Gitane Profile was more like a idea rather than a model, many models existed but all were of the idea to make a profile road bike with aerodynamic features.

Colnago Mexico TT/Aerodynamica (1980)

The Colnago Mexico TT differs in many ways to the original Mexico but the aerodynamic features are as follows. The most prominent parts are the brakes, they were put on the inside of the bike like the Profile. The front wheel was also 650c (when the rear was 700c) The downtube shifters were put on top of the down tube instead of the sides. The fork was specially made to be as sleek as possible. The seatpost provided (I assume) was also profiled.

Cinelli Laser (1981-1992)

I think the Cinelli Laser is most likely one of the most recognisable and talked-about bike of this era. Just about everything as been said about it but I think it's still important to note a few points about this bike in the context of this article. Historically speaking, the Laser is important because it launched TIG-welding into the world of high-end frame building. TIG-welding allowed for more freedom when constructing frames, angles at which the tubes could be connected were close to being free. It also made frames lighter and quicker to make. There is also a visual aspect to the Cinelli Laser, it's instantly recognised through its specific colour (Laser Azzuro) and the aerodynamics gussets that link the different tubes. Apart from this, the interesting part of this bike is the off-set seat tube. Instead of linking the seat knot to the bottom bracket box in a straight line, the seat tube of the Laser goes down and finishes on the down tube. This allows the bike to be shorter and more nervous. It needs to be said that the Laser is not a monolithic model. The Laser was more like an idea that was materialised through multiple different iterations of road, track and time-trial bikes. It would be criminal to not mention the last iteration of this bike, the Pista and Crono Rivoluzione. Where the seat tube is simply removed.