For their SIHH preview, Roger Dubuis, the brand known for innovative materials used on sporty and skeletonized watches, announced two new timepieces – the Roger Dubuis Excalibur Spider Pirelli and the Roger Dubuis Excalibur Aventador S. Both watches further extend the Excalibur line, stay true to the brand’s penchant for skeletonization, and further the brand’s new relationship with Lamborghini.

As part of the Roger Dubuis Excalibur Spider Pirelli collection, both watches have the familiar, aggressive case design and identical proportions at 45mm wide and 14mm thick. The Excalibur Aventador S has a more complex case with various bits made of titanium, carbon fiber, and rubber. The bezel is pink gold, with black markings that give it the aggressive appearance. Even the crown is pink gold with a rubber sleeve or covering. The Excalibur Spider Pirelli chooses to be a little more restrained, and opts for a monochromatic look with plenty of titanium (with black DLC) and rubber.

The use of rubber bits in the crown improves ergonomics significantly, particularly for the hand-wound Excalibur Aventador S. But it can be one of those items that becomes a pain, or impossible to replace after it has worn through. The Roger Dubuis Excalibur Spider Pirelli watches are rated to 50m of water resistance, which is plenty adequate. The whole “Pirelli” portion of the Excalibur Spider Pirelli is in the strap which has a Pirelli motorsport tire inlay and a tire pattern. I’ll confess that I’ve never seen the appeal in this, but it is why the watch is co-branded with Pirelli.

The primary difference between these watches is in the movement and their functions. The Excalibur Aventador S is arguably the more interesting of the two, mechanically, as it features the caliber RD103SQ, which was developed in collaboration with Lamborghini Squadra Corse (the racing arm of the supercar manufacturer) and features double sprung balances linked by a differential. It also has the signature bridge and power reserve indicator inspired by Lamborghini engine blocks. I recommend David’s article on previous Aventador S variants for a more detailed read on the movement.

The caliber RD103SQ is a high-frequency movement, beats at 57,600bph, and is hand-wound with a 40 hour power reserve. To show off the accuracy of the high-beat movement, the brand says it opted for a jumping seconds complication. While the movement is quite impressive and interesting, legibility seems to have fallen to the wayside, unfortunately.

The pink gold seconds hand and black coated minute and hour hands with pink tips camouflage quite easily with the black and pink gold finishing of the movement. The luminous tips salvage legibility to some extent. One could argue that you’d wear this watch simply to enjoy the movement while watching the two balances in action, but it is likely to dissuade buyers who insist that form follows function.

The Roger Dubuis Excalibur Spider Pirelli, the more humble of the two pre-SIHH offerings, features the automatic caliber RD820SQ with a micro-rotor. The skeletonization on this timepiece is more striking at first glance as it doesn’t suffer from the blockiness of the engine-like bridge on the Aventador S. The movement has a monochromatic finish for the most part, with the only color provided by the jewels and the balance. The RD820SQ beats at a more familiar 28,800bph, offers 60 hours of power reserve, and is a time-only piece with hours and minutes – no seconds hand. Like the Excalibur Aventador S, legibility is likely to be an issue here as well.

Like all Roger Dubuis watches produced these days, both the Excalibur Aventador S and the Excalibur Spider Pirelli carry the prestigious Poinçon de Genève certification. I highly recommend reading this extensive article that attempts to discuss the Geneva Seal and Roger Dubuis’ manufacturing process for more information.

If you’ve made it this far into the article, then you’re likely a fan of the aggressive and bold designs that Roger Dubuis is known for. These watches are definitely polarizing and you either get it or you don’t and I think that’s the brand’s approach to watchmaking in general.