Although we did a test bench a year ago on the DB28, which has a very similar case, we felt it would be useful to take a close look at some of the specific characteristics of this DB27 machined from grade 5 titanium, the only alloy of this metal enabling the creation of polished surfaces. The movement is housed inside a fairly simple ‘container’ in the shape of a cylindrical drum implying no particular production difficulties. The famous floating lugs, designed to ensure an ergonomic fit on each wrist, are both effective and technical in terms of their construction and their ‘openworking’ The pivoting points of the shafts at 3 and 9 o’clock led De Bethune to place the crown at 12 o’clock – an obvious technical choice that is also perfectly aesthetically justified thanks to the symmetrical effect it achieves. This choice nonetheless represents one of the rare weak points observed in appraising this timepiece. The effect of the floating-lug spring means that the leather of the strap rests against the fluted crown. Although the latter is screwed in and does not necessarily require handling in this position, one might be tempted to think that the wear and tear at this contact point may end up being visible on the upper side of the strap. The caseback has a conical shape echoing the brand’s main aesthetic signature feature. A small window at 6 o’clock reveals only the sprung balance and the atypical arms of the oscillating weight. The main exterior assets of this timepiece are doubtless the specific dial profile as well as the hands. The successful blend of hand-crafted tradition (silver-toned dial, flame-blued hands) and modern touches (shape of the hands, tamp-printed numeral fonts) is particularly appreciable.
Calibre S233 powering this DB27 is a self-winding movement with a six-day power reserve incorporating the main technological breakthroughs introduced by De Bethune: the twin barrels guaranteeing extremely reduced friction and the development of more constant forces ; the famous white gold and silicon balance-wheel, along with the brand’s characteristic balance-spring ; the triple pare-chute system reducing the influence of shocks on the rate of the watch and actively protecting the pivots of the balance; as well as the oscillating weight made of titanium (to enhance the lightness and rigidity of the plate) and platinum (to deliver an ideal mass/inertia ratio). In addition to showing the hours and minutes, this DB 27 also displays the date, by means of a central hand. The frequency of 28,800 vph in no way detracts from the comfortable power reserve and thus makes this Calibre S233 the ideal movement for daily use. In terms of decoration and finishing, Denis Flageollet has managed to preserve the consistent and balanced approach revealed in the exterior by combining an innovative design with time-honoured decorative standards.
When examining watches for which the manufacturers announce power reserves topping 72 hours, the first step to be taken is to observe the effective duration of their autonomy in order to see how far to measure the rates. It is a well-known fact that in most such instances, the last 24 hours of operation no longer yield acceptable results in terms of timekeeping, so it is scarcely worth looking for results during this final phase. De Bethune speaks of a six-day power reserve for this DB27 and our measurements actually enabled us to add another 21 hours. So what about the results for the first six days? The measurements were taken every 24 hours as the springs gradually let down. At maximum state of wind, the amplitudes ranged from 250° and 295°, while the rates of between +3 seconds/day and +9 seconds/day are worthy of high precision-timing standards. Although the results naturally weaken as the available energy is depleted, the amplitudes and the rates remain very acceptable until the fifth day of running. On the sixth day, however, they deteriorated to the extent that the mean amplitude dropped to 160° with a 53-second variation in rate. The chronometric performances are thus perfectly good in themselves, but it would doubtless be advisable to consider this as a movement with a five-day power reserve rather than six if one wishes to maintain a degree of precision timing that may be deemed irreproachable at this level of fine workmanship.
With this DB27 Titan Hawk, De Bethune delivery exactly what one expects from the brand. The quest for new solutions to the obstacles encountered by wristworn mechanical horology since it was first invented is a constant factor in the approach adopted by David Zanetta and Denis Flageollet. This titanium ‘bird of prey’ effectively reflects the philosophy cultivated by the brand of which the laboratory focuses on improving reliability and precision timing rather than on providing spectacular yet pointless demonstrations. Such is clearly the reasoning behind this DB27 model which, in terms of its intelligent construction, its advanced technological features and its functions, is a candidate clearly eligible for the status of best watch for daily use.