Austrian manufacturer KTM looks set to go full aero with a new concept bike, the Lisse. Sitting pretty in a glass display case at Eurobike with a full complement of Shimano’s new Dura-Ace 9100 groupset, this slick design is still only a mock-up, but KTM expects to have a production bike ready late next year.
KTM designer Gerald Wirthenstätter explained some of the thinking behind the Lisse. The aim was to “clean up” every aspect of a bike’s construction, smoothing and integrating all the major components, hiding the cables fully, and minimising the front cross-section that’s exposed to the wind. At the same time, KTM didn’t want to compromise on user-friendliness or the ability to run mechanical groupsets without major headaches. So-called “top to bottom” internal cable routing is designed to make building the Lisse a cinch, with all cables routed in housings that guide through the whole frame – there shouldn’t be any fishing around and swearing with this one.
The Lisse bears some resemblance to existing aero designs with now-common features like the dropped seat stays and the hidden seat wedge, but it takes things much further. At the front end, the stem is fully integrated and instead of employing conventional spacers to adjust the stack, specially-shaped shims adjust the stem angle in a five-step range.
The integrated stem can be set to one of five angles using special shims Matthew Allen / Immediate Media
The front brake is neatly hidden behind the fork while the rear sits on top of the chainstays, out of the airflow and also away from the worst of the muck. At the dropouts the usual chunky quick releases are replaced by neat bolt-thru axles whose ends blend almost seamlessly with the fork legs. (For racing purposes, the bike will also accept standard skewers.) More radically, the bottom bracket shell has a unique asymmetric shape that’s designed to direct airflow to the less-draggy non-driveside of the bike, an idea which sounds almost too sensible to actually work.
The Lisse’s bottom bracket is designed to direct airflow to the non-driveside of the bike Matthew Allen / Immediate Media
The most visually arresting part of the Lisse’s frameset has got to be the seatstays, which emerge from the seat tube as a sort of horizontal shelf, before dividing into two wide-but-exceptionally-thin blades, again in aid of producing the smoothest possible airflow.
These are not your average seat stays Matthew Allen / Immediate Media
As the Lisse is still a concept there are no claims of X numbers of watts saved at Y kilometres per hour and we’ve got no idea what the finished article might weigh, nor indeed how much it will cost. It’s an interesting piece of design however, one we’ll be looking out for at Eurobike 2017 – check out the gallery above for some more details pics.