Pinarello Dogma K8-S rear-suspension road bike released
Team Sky in conjunction with Jaguar has unveiled the new Pinarello DOGMA K8-S for the Tour of Flanders and Paris-Roubaix. The bike is set to feature on the cobbles of this year’s Tour de France, but Bradley Wiggins, Geraint Thomas and Luke Rowe will be among the first Team Sky athletes to race the bike this weekend in Flanders.
The new bike, with a claimed raw frame weight of 900g, has a bespoke mechanical rear suspension system called the DSS 1.0 – Dogma Suspension System – that features a miniature rear shock and flexible flat carbon chainstays that Pinarello believes “creates a revolutionary pivot point for the perfect riding comfort over the cobbles of northern Belgian and France”.
BikeRadar’s sister site Cyclingnews joined Team Sky riders Geraint Thomas, Luke Rowe and Salvatore Puccio as they rode the final 100km of the Tour of Flanders route on Thursday as part of their final preparations ahead of Sunday’s Monument, and the feedback from the riders was expectedly positive.
“I’m in the best shape I’ve been in, and the team are in the best shape they’ve been in, and we’ve got a lovely new bike,” Thomas said.
“I rode [the bike] in February as well and it feels nice. The faster you go you can tell the difference even more. The back end definitely feels a lot comfier – not so rigid.”
The new rear suspension unit has been co-engineered by Pinarello, the team’s bike supplier since their WorldTour inception in 2010, and Jaguar, which initially joined the team as vehicle supplier that same year.
The pinarello dogma k8-s: the pinarello dogma k8-s
The starting point for Pinarello’s development started with the K8 road bike with the main triangle acting as the foundation of the project. As is typical for bikes purpose-built for the cobbled Classics, the front end is built with a slacker head tube angle than usual, while the fork rake has increased by 4mm. In total, this should make for better shock absorption up front along with increased stability given the longer wheelbase.
The major developments to the bike are at the rear end, however. The chainstays have been thinned out and the seatstays incorporate a molded-in pivot point. Up top, a small elastomer-based shock is inserted in between the seatstays and seat tube. Meanwhile, the chainstays are wider horizontally to maintain stiffness from side to side.
“We needed them to be able to flex and we designed them in order to make sure that rear wheel had the capacity for 10mm of vertical travel,” Pinarello’s Massimo Poloniato told Cyclingnews.
The DSS 1.0
Suspension on Roubaix bikes is nothing new and Pinarello confirmed that several DSS test mules were developed, with the first prototype a complete shift from the finished version Team Sky are set to use.
“We performed several tests on the suspension both in a machine in our factory and some other tests with riders on the cobbles. For example, Wiggins has tested this bike on the cobbles of Roubaix,” Poloniato added.
Jaguar also played its part in the DSS 1.0 development, with its own testing carried out. “They helped compare a lot of the data we had collected and had their own tests. All of the testing helped us evolve through several prototypes.”
Elastomer suspension isn’t new to road bikes, but it is new to pinarello: elastomer suspension isn’t new to road bikes, but it is new to pinarello
One key aspect of that testing was dialing in the specific shape, material, and density of the elastomer shock so that it damps road vibrations but without moving excessively under rider power.
Finally, Pinarello opted for direct-mount rim brake calipers that not only provide better stopping performance and clearance than traditional center-mount brakes but also make it possible to assemble the rear shock into the frame.
The power results
Poloniato acknowledged that with any suspension addition there was a risk of power loss from the rider to the bike. However, he added that such a concern had been a major consideration at Pinarello during the development phase and that the test results were positive.
“Firstly, the riders have told us that on flat sections of road they can’t feel the suspension. It’s like it doesn’t exist on smooth roads. That’s a good indication. Of course we want to do more tests in the future but the work with Jaguar has been key in this part of the project. With them, we’ve found that there’s an eight percent increase in speed over cobbles when the power remains constant between the current bike and the K8-S.”
More steps to come
While Pinarello and Team Sky are publicly content with the results that new bike has produced, Poloniato stressed that the Italian manufacturer – in conjunction with Jaguar – would not be resting on its laurels.
“I think that there’s more that we can do with the materials we’ve used or improving some of the components within the suspension. For sure, on a bike in the future we want to work on the weight and the dimensions of the suspension system.”
The new bike was released ahead of the cobbled classics, the tour of flanders and paris-roubaix: the new bike was released ahead of the cobbled classics, the tour of flanders and paris-roubaix
Suspension over the stones also comes from the tubulars, of course, and Team Sky has handmade options from FMB