Developing a key component of Campagnolo Ekar: The rear mech

12th Oct 2020

The heart of Ekar – developing the derailleur.

The Ekar development team have been working on the gravel groupset for literally years. Here they give some insight into the processes…

“We chose the carbon fiber polyamide for the weight, but also for the aesthetic design of the cage and the body… because in the end we are still Italians!”

The Ekar groupset is designed specifically for gravel use, and has been built as a completely new product from the ground up. Of course that development relies on Campagnolo’s technical knowledge and heritage of innovation.

But what does it mean to make a high quality groupset starting with a blank sheet of paper?

The start point is actually understanding exactly what this kind of rider – and riding – needs. That defines the mission statement and the brief to the design team.

     
 

Then begins the process of design on paper, on computer and using mathematics at a level that many of us won’t even try to understand, developing designs and testing prototypes – both out on the roads and trails, and in the lab – providing ‘real world’ and scientific feedback to go into a cycle of redesign, redevelopment, and honing. It’s no easy task. Especially when you consider that you’re not looking at one component in isolation.


 

It demands that derailleurchaincassettebottom bracket and chainringscontrollers and braking system all work together harmoniously.

But at its heart is the derailleur – only a rear of course, as Ekar is a pure 1x system. The design brief included having a full range of gearing ratios, with small, predictable steps to manage cadence. It had to be tough, durable and long-lasting, yet lightweight – and of course, it had to look and feel good!

Ekar’s Product Manager and R&D Technical Lead explains the process of turning a great idea into a product that performs perfectly on your gravel bike.

“We knew that we had to go to 13-speed to enable 1x. So that was the point that we started from,” explained the guys. “From an R&D perspective we needed to redesign the derailleur completely because Campagnolo has previously worked with double or triple chainrings. So we had to optimise the geometry, the motion and the angle of the derailleur, for its ability to move across the sprockets.”

 

 

Part of the challenge was to create a derailleur that works with the three different cassette options – 9-36, 9-42, 10-44 – with the same cage...

“So we worked out that the 15-degree angle of the derailleur matched with the two-dimensional movement allowed us to fulfil all the specifications. We started with drawings, concepts like chain width, the dimensions and diameter of the sprockets we need, determining where the derailleur needs to go, then we could design the cage, so that the higher pulley could be in a specific point to match the cone shape of the cassette.”

The team determined that a 2D derailleur was the best way to follow the jump from one sprocket to another – there are six 1-tooth gaps then higher jumps: 2, 3, 4 tooth – it’s something that’s never been done before. While the maximum gearing range was already defined, the ratio steps were not.

“We made considerations about the ratio changes and the metrics,” say the development team, “So we needed to make something that is smooth. We made a lot of studies based on the numbers in the early stages, and then we could develop all the other features. The early studies – the brainstorming – started about five years ago, exploring what would be necessary for such different gears which are not used for road. The first prototypes were made about three years ago.”

The R&D team knew they had to find the right balance of materials, for example the bolts had to be stainless steel because they are exposed to the elements.

“We chose the different alloys for strength and weight reduction. And the carbon fiber polyamide for the weight, but also for the aesthetic design of the cage and the body… because in the end we are still Italians!”

 

 

There were challenges in tolerances with Ekar’s new narrower chain, sprocket spacing and creating a derailleur to work precisely, accurately and reliably...

“At Campagnolo, we live together with the need for high tolerances. We work with 1/100th of a millimeter as a tolerance reference. This is normal.”

For gravel, a clutch is expected, but was also a new challenge for Campagnolo.

“It took a lot of work to create it within our standards, which are of course top of the range. Our clutch is very durable.”

Testing shows that it has a lifetime that is significantly longer than some others. And to develop it, the team had to create new, specific tests.

“If you put a rider on a bike with a new design prototype it’s not too easy to understand the results, because of the differences on the day – the way a rider took at jump, say at a higher speed or a lower speed than another day,” they explain. “We needed something in the laboratory where we could compare one test with another. So we had the same rider doing repeat laps over the same terrain, using a telemetry recording system, which we then interpreted and replicated in a machine in our lab to test them in a mathematical way. "

“There are thousands of different combinations of bike, rider, weight, terrain. So we established the correct force that the clutch has to apply on the chain and the transmission to have the stability and security we required. “We put more than 10 different prototypes on the test machine to see if the tension was what we wanted to achieve, and how many cycles it would last. After testing on the machine, we went back out to double-check it on the ground… to check the real feeling. It was a full testing cycle.”

The development team are rightly proud of what they have achieved with Ekar. As riders they know that for all the good ideas and development processes, the real test of the gravel groupset is out on the trails and tracks you love.

And that’s where we proved it.

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