We revealed earlier this year that BOS engineering had enlisted the services of never-quite-managing-to-retire Nicolas Vouilloz, with the duo having worked together previously on developing the Sunn bikes used in many World Cup victories.

The result of the renewed pairing is the launch of an all-new DH fork, the Idylle Pro. BOS’s last work on a MTB product was on Vouillaz’s V-Process fork. When the Frenchman departed in search of success in World Rally, BOS followed suit, taking its knowledge gained with DH MTB racing to the rally cars and motorbikes it would later work on.

BOS clearly learnt a lot about suspension design and setup during its involvement with motorsport, and the latest fork owes much to the shocks used on cars such as the Mitsubishi WRC.

The Idylle Pro fork is based around a pressurised damping system, with a single damping cartridge inside and a piggy-back reservoir attached to the right-hand side lower leg. A not-ungenerous 200mm of travel is on tap. There’s high and low-speed compression adjustment, with the dial located on the piggy-back reservoir, rebound adjustment, adjustable hydraulic bottom-out.

When asked on the reasons for using a pressurised fork design, BOS says: “The key advantage of a pressurised fork is that it works like a rear shock. In brief, the hydraulics are both more constant and more reactive. Also, the damping can be separated from the lubrication (all governed by the same hydraulic oil in most conventional forks). The fork uses two different types of oil: one for lubrication, ie the smooth operation of the fork, and the other for damping.”

The fork features 36mm stanchions made from 7050 aluminium, magnesium lowers, a 1 1/8in steerer, 20mm bolt-through axle and post-mount disc mounts.

Testing is currently being undertaken by Nicolas Vouilloz and Fabien Pedemanaud. More information at www.bos-engineering.com.