De Bethune DB28T (Tourbillon)

Launched in early 2011, the De Bethune DB28 model now comes in a tourbillon version.

The external features remain same: Dedicated shape of the case, crown at 12 o’clock, the dial that acts as a window onto the movement, polished and matt surface, the delta-shaped polished steel main plate and De Bethune “stripes” combined with a chapter ring and lastly the “floating lugs”, all remains same that of DB 28 model.

The case is entirely made in titanium. Instead of the spherical moon at 6’ o clock, this new watch features the De Bethune tourbillon, plus the power reserve indicator.

The DB28T is powered by Calibre DB 2009 a mechanical hand‐wound movement which is equipped with an ultralight 0.18 gram silicon/titanium tourbillon.

De Bethune thus undertook to rethink the tourbillon around this new wristwatch dynamic. The laws of physics are implacable: in order to compensate for the disorganized violence of wrist movements, the carriage must be as light as possible with as high a frequency as possible and a maximum rotation speed for a minimum mass and inertia.

Thanks to new technologies, De Bethune has therefore created a 0.18 g silicon-titanium tourbillon in a carriage spinning once every thirty seconds at its axis, and a balance oscillating at a frequency of 36,000 vibrations per hour. This tourbillon is the lightest on the market (classic counterparts weigh four times as much) and comprises 50 parts, of which the lightest weighs less than 0.0001 grams and the “heaviest” 0.0276 grams.

Technical details

Model: De Bethune DB28T (Tourbillon)

Functions
Hours, minutes, power reserve, tourbillon 30”

Movement
Calibre DB 2009 – mechanical hand‐wound movement
298 components – hand-decorated with circular-grained, snailed, chamfered and polished steel parts,
Côtes De Bethune
Self-regulating twin barrel
Silicon/platinum balance wheel with flat terminal curve
Ultra-light 0.18 gram silicon/titanium tourbillon
Triple pare-chute shock-absorbing system
Jewelling: 33
Frequency: 36.000 vibrations per hour
Power reserve: 5 days

Case
Classic round-shaped case 45 x 42 mm in diameter and 11 mm thick
Floating lugs in grade 5 titanium with pivoting system. Their springs follow the shape of the wrist and its movements – Available in short or long size
Crystal: Sapphire crystal, 1800 Vickers hardness with double anti‐reflective treatment
Crown: at 12 o’clock, setting in two positions
Case back: Solid “hunter-type” back inspired by pocket-watch, with horizontally controlled power-reserve indicator

Dial
Black polished stainless steel, tourbillon at 6 o’clock

Strap
Extra-supple alligator leather with pin buckle