Disc brakes and thru-axles plus even more tire clearance
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Trek has added two disc brake-equipped variants of its outstanding Domane endurance bike. The top-end Domane Disc 6.9 shown here costs US$7,899 / £6,000 and weighs just 7.52kg/16.58lb(Image credit: Jonny Irick)
The new Bontrager Affinity Elite Disc TLR wheels use the company's so-called 'stacked' spoke lacing pattern that supposedly boosts wheel stiffness by pushing the spokes further apart(Image credit: Jonny Irick)
Coming with the Trek Domane Disc 6.9 are new Bontrager Affinity Elite Disc TLR wheels wrapped with 25mm-wide Bontrager R3 tires. Internal rim width is 17mm(Image credit: Jonny Irick)
The Shimano Dura-Ace Di2 9070 rear derailleur moves the chain across a wide-range 11-28T cassette(Image credit: Jonny Irick)
Cable routing is fully internal (save for the front brake). The derailleur routing is convertible between electronic and mechanical drivetrains(Image credit: Jonny Irick)
Fender mounts are discreetly hidden throughout(Image credit: Jonny Irick)
The top-end Trek Domane Disc 6.9 comes with Shimano's outstanding R785 full-hydraulic disc brake setup(Image credit: Jonny Irick)
The rear disc caliper is neatly tucked away in between the stays(Image credit: Jonny Irick)
The seat stays are pushed further rearward to make room for the disc brake caliper(Image credit: Jonny Irick)
160mm-diameter rotors come standard on the Trek Domane but both ends are compatible with 140mm discs(Image credit: Jonny Irick)
Sitting at the base of the flared and ovalized seat tube is Trek's integrated chain catcher. Note the generously proportioned 90mm-wide bottom bracket shell, too(Image credit: Jonny Irick)
The head tube surrounds a 1 1/8-to-1 1/2in tapered steerer(Image credit: Jonny Irick)
The IsoSpeed fork uses unusually forward-swept blades, which provides more of a leaf spring effect on bumps. The dropouts reach slightly rearward, however, in order to maintain a standard offset(Image credit: Jonny Irick)
There's no need for a brake bridge with the addition of disc calipers, which increases tire clearance(Image credit: Jonny Irick)
Since its inception, the defining feature of all Trek Domane endurance bikes has been the IsoSpeed 'decoupler'. This allows the seat tube to pivot independently of the top tube and seat stays and makes for a remarkably comfortable ride(Image credit: Jonny Irick)
Front brake hose routing is functionally without fault but could be a little prettier to look at(Image credit: Jonny Irick)
Trek have announced the release of two new Domane endurance bikes, both with the same fantastic bump-eating ride of the original series but now with disc brakes and thru-axles at both ends. The changes will of course add a little bit of weight but also superb all-weather capabilities plus additional tire clearance, too.
The top-end Domane Disc 6.9 (US$7,899 / £6,000 / AU$9,499) uses Trek's upper-end 600-series OCLV carbon fiber blend, an integrated no-cut seatmast, and a premium parts blend that includes a Shimano Dura-Ace Di2 9070 electronic transmission, Shimano R785 STI Dual Control levers and hydraulic disc brake calipers, a carbon fiber Bontrager bar and saddle, and Bontrager's brand-new Affinity TLR Disc alloy clincher wheelset.
The far less expensive Domane Disc 4.0 (US$2,099 / £1,600 / AU$n/a) subs in Trek's 400-series carbon fiber formula and a standard telescoping seatpost (which adds weight and firms up the ride quality). Of course, the parts spec is more budget friendly as well with a Shimano Sora 9-speed transmission and STI Dual Control levers, TRP HY/RD mechanical-to-hydraulic disc brake calipers, alloy Bontrager cockpit components, and a more basic Bontrager wheelset.
We don't expect many (if any) buyers will do so but if so inclined, both the 142x12mm rear and 100x15mm thru-axle dropouts on both bikes are convertible for use with standard quick-release disc wheels. The fork tips can also be swapped from left to right so that users can decide for themselves on what side of the bike they'd prefer the lever to reside.
With the switch to disc brakes – and the resultant omission of the brake bridge on the seat stays – the frames will now have room for even bigger tires than on the standard Domane, too. Both bikes will come stock with 25mm-wide rubber but by our measurements, tires as big as 30mm might fit depending on the make and model.
Otherwise, both bikes carry over features from the standard Domane carbon chassis, including the superb IsoSpeed 'decoupler' at the seat cluster and matching IsoSpeed extra-curved carbon fork, convertible internal cable routing, a tapered 1 1/8-to-1 1/2in front end, the 90mm-wide BB90 bottom bracket shell with directly pressed-in bearings, an integrated chain catcher, keenly hidden fender mounts, and a pocket in the non-driveside chain stay for Bontrager's DuoTrap wireless speed and cadence sensor.
We recently received a Domane Disc 6.9 sample here at BikeRadar's Colorado office so expect a more in-depth review soon. Actual weight for a 52cm sample without pedals is an impressive 7.52kg/16.58lb.
That said – and especially given the UCI's stated intentions on disc brakes in the pro ranks – we expect that a disc-equipped Madone isn't far behind, even if it's made available to the public before being widely adopted by seasoned professionals.
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