Julien Absalon on dropper post and Di2 in Cairns

Dousing himself in water after practising the humid and technical course at the first World Cup round of 2016, Julien Absalon is quite nonchalant about his use of a dropper seatpost.

Casual he may be, but it’s a rather significant component choice and sign of the times regarding cross-country's ever more demanding courses. Absalon, a two-time Olympic gold medallist and five-time world champion is a true veteran of the racing format and yet his bike is a showcase of the industry’s latest trends – a surprising fact given how stubborn to change cross-country riders typically are.

Riding 'Jacob's Ladder' in Cairns, Absalon was clearly making use of his dropper post on the steep and rocky descent

Glen Jacobs – Cairns local and owner of trail building company World Trail – had told us back in 2014 that he designed the Cairns world cup cross-country course in hope of seeing many of the world’s best take to dropper posts. While he was disappointed back then, it seems his wishes have come true and there are few riders in the world more influential than Absalon himself.

Fourstroke with extra carbon

For much of the season, we’re told Absalon will pick the 100mm travel BMC Fourstroke 01 over the TeamElite soft-tail. This full-carbon frame is without question one of the more premium dual suspension race options on the market, and there are no team-only tricks here. Just as he did to win the 2014 World Championships, Absalon rides a standard medium frame.

Using BMC’s long-proven APS suspension system, the 29in-wheeled Fourstroke offers a full list of the latest trends: 142x12mm rear axle, carbon Shimano press-fit bottom bracket shell and plenty of asymmetry.

A peak at a prototype carbon rockerlink on absalon's race bike. it has 'impec' printed on it, which refers to bmc's own swiss-based carbon manufacturing facility: a peak at a prototype carbon rockerlink on absalon's race bike. it has 'impec' printed on it, which refers to bmc's own swiss-based carbon manufacturing facility

Prototype carbon rocker link in testing

Where the frame may be something you can by off the shelf, Absalon’s race bike provides hints of what may be to come. There’s a prototype carbon rocker-link on his main bike, just a small part but something that likely saves weight without loss in rear end stiffness. It’s clear this part isn’t quite perfected just yet, as his spare/training bike (as photographed) still has the stock alloy piece.

Shimano and Fox zap together

Absalon was one of three in the world to first race Shimano’s XTR Di2, and two years on is still riding the flagship electronic group. Offering insanely precise and reliable shifting at the easy push of a button, Di2 isn’t affected by mud, clutch-induced shifting resistance or a stretched cable and so makes plenty of sense for mountain biking. Such benefits certainly carry a significant price penalty for the non-sponsored rider, however.

While Di2 is still unusual off-road, the integration with Fox’s iRD electronic lockouts is even rarer. Here, the Fox system is built to Shimano’s E-tube wiring standard and even shares the Di2 battery.

Plenty happening at the left, note the 'south paw' dropper post remove and fox ird switch: plenty happening at the left, note the 'south paw' dropper post remove and fox ird switch

No worrying about front shifting, but those levers have just been replaced with others

Due to his preferred single-ring setup, Absalon’s left hand is kept free to control his suspension and dropper post. Sitting between the grip and brake lever is a little trigger to lock both front and rear shocks in conjunction.

That suspension in itself is rather trick, with the front fork being the just-released 32 Step-Cast, Fox’s lightest fork to date and something designed specifically for cross-country racing.

Fox’s new 32 Step-Cast fork hits the XC sweetspot

Tucked into the base of the steerer, there’s a clever custom expanding wedge used to keep control of the Di2 wires coming from the fork and shift control unit. This then feeds on to the down tube.

Typically the Di2 battery is wedged into the base of the seatpost, but the use of a dropper complicates this greatly. To overcome this, Absalon’s mechanic Sylvain Golay got creative and taped the battery directly to the dropper post's internal cable.

Another view of that special carbon chainguide made by bmc, for bmc : another view of that special carbon chainguide made by bmc, for bmc

Prototype chainring and a carbon chain guide

Looking to that single ring and Absalon seems to be riding an early prototype from the Japanese company. Shimano has just released an update to its original and short-lived single-ring design and so Absalon’s use of a pre-production ring is not unusual.

Ensuring the chain doesn’t leave its ring, Absalon’s bike has a BMC-made carbon chain catcher. It’s an item that bolts directly to the Fourstroke’s down tube on a proprietary mount.

Back to that seatpost

Now that's a first at a world cup. absalon on a ks lev ci dropper seatpost. pictured is a standard lev in a 100mm for his training bike: now that's a first at a world cup. absalon on a ks lev ci dropper seatpost. pictured is a standard lev in a 100mm for his training bike

A longer travel 100mm LEV for Absalon's training bike

Absalon’s use of a KS LEV CI dropper is no small deal. We believe it’s a first for a rider of this level to race with a dropper post in a World Cup. Both his training bike and race bike were equipped with remote-activated KS seatposts, although the former featured a standard LEV 100mm version with the latter using the lighter and shorter 65mm drop LEV CI.

This relatively new carbon dropper seatpost is built for this exact purpose in mind and claimed to be the lightest on the market at 436g. Still, at this level every gram counts and that’s about 250g more than a lightweight rigid post.

The stealth-routed post links up to a KS Southpaw lever at the bar, which works much like a thumb shifter.

Bolt-up axles built for speed

Front and rear, absalon's bike uses bolt-up thru-axles which are made by ôshift-upõ. such an item is popular in cross country for saving crucial grams : front and rear, absalon's bike uses bolt-up thru-axles which are made by ôshift-upõ. such an item is popular in cross country for saving crucial grams

Low profile and made for the torque of an impact driver

Quick wheel removal speed and bolt-up thru-axles don’t often go together, but Absalon’s bike features special alloy axles made by Shift-Up. Most unique is the 8mm hex keyhole, which is said to allow for easier entry of a hex wrench compared to a more common 5mm bore. The bigger size is also built to withstand the forces from an extremely quick impact gun – allowing for F1-like wheel changes.

Being secretive

When it comes to pro-bikes, logos are only ever missing if they conflict with existing sponsorship agreements. Such is the case with Absalon’s wheels, which clearly lack branding.

Sponsored by Shimano, Absalon has access to the race-specific and impressively light XTR tubular wheels. Unfortunately, this wheel choice would likely conflict with options from another sponsor – Continental.

So therefore Absalon is left with the XTR M9000 tubeless wheels. These carbon/alloy hybrid wheels do plenty things right, but as we’ve pointed out in a recent review, they’re just not weight-competitive at this level. And so unfortunately this type of situation typically forces the rider to upset a sponsor in order to gain every edge possible.

These unbranded rims carry a rather recognizable profile. our guess is stan's race gold: these unbranded rims carry a rather recognizable profile. our guess is stan's race gold

Familar looking rims sit without labels

Based on the external profile, we suspect the rims are Stan’s Race Golds – one of the very lightest available. These are laced with bladed spokes (either DT Swiss Aerolite or Sapim CX-Ray) and then wire tied for additional stiffness. The rear hub is clearly a Shimano XTR, however we’re unsure on exactly what the front is.

All up, we weighed Absalon’s race bike at 10.18kg (22.44lb). Some may have expected lighter for a bike of this level, but consider the dropper seatpost, fairly ‘normal’ tyres and all the electronics and this is an impressive figure with little compromise to reliability.

Absalon is set to retire at the close of this season, certainly expect big things as this fast and friendly Frenchman looks to earn his third gold medal come Rio.

Complete bike specifications

Frame: BMC Fourstroke 01, size Medium, prototype carbon rocker
Rear shock: Fox Float DPS Factory iRD
Fork: Fox 32 Step-Cast iRD
Headset: Sealed bearing
Stem: 3T ARX II Team, 100mm, -6 degree
Handlebar: 3T ‘BMC Team Issue’ carbon, 680mm (swapping to 700), flat
Grips: Lizard Skins DSP
Front brake: Shimano XTR M9000, Race pads, 160mm IceTech centerlock rotor
Rear brake: Shimano XTR M9000, Race pads, 160mm IceTech centerlock rotor
Rear derailleur: Shimano XTR Di2 9050
Shift levers: Shimano XTR Di2 M9050 right
Cassette: Shimano XTR M9000 11-40T 11-speed
Chain: Shimano M901
Crankset: Shimano XTR M9000, 175mm, 34T chainring
Bottom bracket: Shimano pressfit
Pedals: Something French (BMC requested we don’t publish specifics)
Front wheel: Custom – Misc 15mm front hub, Sapim CX-Ray spokes (wire tied), Stans Race Gold 29 rim (assumed)
Rear wheel: Custom – Shimano XTR M9000 142x12mm rear hub, Sapim CX-Ray spokes (wire tied), Stans Race Gold 29 rim (assumed)
Front tyre: Continental Race King 29x2.2in, setup tubeless
Rear tyre: Continental Race King 29x2.2in, setup tubeless
Saddle: Fizik Antares R1 braided
Seatpost: KS Lev CI, 65mm (race), (100mm version for training)
Bottle cages: Elite Paron carbon
Other accessories: Custom ‘Shift-up’ bolt-up thru-axles

Critical measurements

Rider's height: 1.8m (5ft 11in)
Rider's weight: 68kg (150lb)
Saddle height from BB, c-t: 741mm
Saddle setback: 67mm
Seat tube length (c-t): 460mm
Head tube length: 100mm
Top tube length (effective): 610mm
Weight: 10.18kg (22.44lb)

Note: many photos in the gallery depict Absalon's spare/training bike which was also brought to Cairns. To our knowledge, his race bike is only different from its shorter and lighter dropper seatpost and the carbon rockerlink.