Is this diamond-encrusted Harley-Davidson the world's most expensive motorcycle?

WHAT do you get if you cross a Swiss watchmaker and an all-American motorcycle manufacturer?

The world’s most expensive motorcycle probably wouldn’t be your first answer, but that’s the result of a collaboration between Carl F. Bucherer and the Harley-Davidson specialist Bündnerbike.

Based on a Harley-Davidson Softail Slim S, the Blue Edition is unrecognisable from its former self, after a team of eight people spent a total of 2,500 hours crafting it into a bespoke, jewel-encrusted thing of beauty.

Heat-resistant LEDs light the engine from within, showcasing the gold-plated throttle valves. Diamonds adorn the forks and handlebars and a cowhide saddle is positioned low between the curved fuel tank and the huge back wheel.

But most impressive of all is the tank’s opulent accessories.

On the left hand side is an armoured glass dome shielding a retractable safe containing a 5.40ct diamond six-prong Heaven solitaire ring by Bucherer Fine Jewellery.

And on the other side is a custom-made Carl F. Bucherer watch based on the Patravi TravelTec II. Its holder – a cage made from silicon rings – also works to keep the watch fully wound even when the motorbike is not being used.

The one-off bike, which has been built to display the best of both manufacturers, will also be supplied with a second watch, featuring design elements of the Blue Edition custom Harley on the dial so that, Bucherer says, “even when not riding the motorcycle, the buyer will therefore always have a piece of the pinnacle of Swiss watchmaking at his or her side.”

This latest addition to the Bucherer Blue Editions collection is offered for 1.89 million Swiss francs (£1.4 million), which appears to be more than any motorcycle has sold for before.