The earliest concepts of Shimano’s hydraulic road disc brake first appeared on meeting agendas at the company’s headquarters in Europe and Japan six years ago. The decision taken at that early stage was that the market wasn’t ready for such a product. Subsequent developments, notably the increased popularity among amateur riders for full carbon clinchers (a product Shimano still refuses to manufacture on safety grounds), and the drastic consequences of melted resin in the brake track, has convinced Shimano that the time for a hydraulic disc brake for road bikes is now.
The development process began with Shimano giving mechanical disc brakes with hydraulic convertors to cyclo-cross riders from Rabobank, FDJ and BKCP, including 2011/12 world champion Niels Albert, and asking them to describe the performance they wanted from a hydraulic disc brake.
The first trial of the road hydraulic disc brakes took place in the mountains of Japan, in wet conditions, with European product co-ordinator Tim Gerrits finding himself obliged by his Japanese employers to don body armour. Having convinced them of its safety, Gerrits would later conduct tests in a weighted diving belt to boost his bulk to 130kg before performing drag tests on mountains in America. The final phase of testing, completed by former Orica-GreenEDGE rider, Lars Teutenberg, two weeks before the Eurobike show in August, took place on some of the highest mountains in Europe, including descents from two summits in the Italian Dolomites made famous by the Giro d’Italia: the Passo di Gavia and the Passo dello Stelvio.
A more succinct answer to the question ‘where does it come from’ might be provided with a glance at the Japanese firm’s XT mountain bike caliper, a unit Shimano has adapted for road use. While most of the technical development of their new road brake can be found in the ST-R785 lever, this also contains technologies developed in Shimano’s off-road range.