Watch marques are prone to re-issuing their classic models with new design ticks. At last week's Salon International de la Haute Horlogerie (SIHH) in Geneva - the first major watch fair of the year - the reappearance of Van Cleef & Arpels' 'Cadenas' watch (French for 'padlock') made a welcome return.

Created in 1935, the Cadenas is a shining example of hardware as high jewellery. But it's always hard to improve on a design classic, a challenge that Van Cleef & Arpels' CEO and creative director Nicolas Bos was faced with when he and his team sat down to re-imagine the bracelet-watch for 2015. 

'It has nothing to do with what we know as traditional watch design,' he says. 'We have a heritage of creating bold, innovative objects; transformable jewels, such as our 1950s Zip necklace, which can be deconstructed into several pieces,' says Bos. 'For 2015 we tried to alter the angle of the Cadenas' dial, but then we realised the watch was too difficult to read.' 

As Bos says: 'The Cadenas has a distinctive personality. It doesn't have a round dial and does not sit flat on the wrist.' There is a Cubist influence in its raised faceted case, at odds with the gently curving bracelet. But that geometry is purposeful: the dial was angled to allow women to glance at their wrist without appearing to read the time, a social faux pas in the early 20th century.

'Effectively, we sought to improve the shape of the Cadenas but realised we couldn't,' says Bos. Rather, the team enhanced the watch's readability by enlarging, slightly, its oblong dial and applying 12-hour markers to the crystal cover, making it easier to read. The original double snake chain bracelet remains, as does the hoop of the 'lock', carefully considered to soften the graphic edge of the dial.

The clasp is also updated, with two small ceramic beads inserted to make a more secure fastening. 'We revisited the whole clasp system so that the bracelet makes a satisfying click sound when you fasten it - a technology more in keeping with today,' says Bos. 

Nine new Cadenas models have been launched but the yellow-gold padlock watch with mother-of-pearl dial - which harks back to that simple but brilliant 1930s vision - is the watch that gets our vote as best in show.