The fact that mountain bike technology is increasingly being used on road bikes is not least due to a new category of two-wheeler: the gravel bike is not an asphalt racer or a cross bike, but a comfortable racer that also cuts a fine figure on unpaved paths.

Sram builds single-chainring groupset for road bikes
Sram is now launching the "1x" groupset for precisely this application. As usual on mountain bikes, the crankset features a single chainring, which is available in sizes 38, 40, 42, 44, 46, 48, 50, 52 and 54 teeth. Four cassette gradations are available: 11-30, 11-32, 11-36 and 10-42 teeth. The 10-42 cassette requires the XD-Driver freehub from Sram on the rear hub, the other cassettes do not.

The rear derailleurs are directly adapted from mountain bike technology, or more precisely from the technology derived from the CX1 cross group. These keep the chain taut and only move in a horizontal axis, keeping the derailleur pallet under tension. The new groupsets from Sram, which rely on single-chainring technology, are called Sram Rival 1 and Force 1. At the same time, the groupsets with a 2x chainring set are still in the portfolio.

UCI tests disc on road bikes
Professional road cyclists are also set to benefit from mountain bike technology. Disc brakes have been established on road bikes since 2014, with Sram and Shimano offering several groupsets - but the racing teams cannot compete with disc brake systems on their bikes.

Stage-by-stage introduction
But the UCI is now relenting: During the UCI Professional Road Season, all teams are permitted to use racing bikes with disc brakes in two races in August and September 2015. During the 2016 racing season, disc brakes will be permitted for testing purposes at all competitions. The official OK for road discs will then be given for the 2017 season, and the plan is to approve road discs at all levels of road racing if the experience is positive.

UCI President Brian Cookson says: "Disc brakes have been in use on mountain bikes for over a decade and in cyclocross for two years. However, its use in road cycling must be carefully examined in cooperation with riders, teams and manufacturers."