Ride Quality
With its proprietary IsoSpeed Decoupler system—pseudo-suspension where the one-piece top tube/seatstay are not connected to the seat tube, allowing the seat tube to flex freely, which they say doubles compliance—the ride quality on the Trek Domane 6.9 Disc is outstanding. Bumps, potholes, gravel and yes, cobbles, are no longer an energy sapping nuisance. They become fun challenges to be welcomed, not feared. This is combined with fully separate, narrow seatstays that further enhance ride quality. But lest this become too “bouncy” in the rear, Trek wisely uses their adjustable seatmast system with a standard 27.2mm post, which keeps the seat post from over flexing as in other bikes. Compliance occurs lower in the rear triangle and is therefore less noticeable than in the seat post, and less disturbing to pedaling rhythm. Carbon bars also keep the vibration down in the hands and arms, although the alloy rims don’t help—another reason carbon wheels would be better on this bike.  

Stiffness-to-Weight/Power Transfer
Considering its excellent ride quality, one might expect the Trek Domane 6.9 Disc to suffer in this area, but that’s not the case. The bike comes in at a decent 17 pounds, a bit on the heavier side, but combined with a stiff, responsive lower section, the bike can accelerate and climb impressively. The head tube length (175mm) and angle (71.9-degrees) are not extreme and provide a good balance of comfort and stiffness, so even out-of-the-saddle sprints and climbs don’t result in major flex in the front end. However, extra weight in the not-so-light rims can affect acceleration, and seat tube flex under heavy load reduces efficiency compared to traditional frames.  

Climbing/Efficiency
Like many in the endurance category, the rider position on the Trek Domane 6.9 Disc makes it a very comfortable climber, especially on long sustained climbs at lower gradients. This one also has the benefit of very stiff, responsive bottom half, with only slight give in the front end under heavy torque situations like stand-up efforts and sprints. Again, a lighter wheelset would help here, as the bike comes in a full pound heavier than the lightest in our test, but otherwise this is an excellent climber.

Descending/Handling  
The solid front end and thru-axles keep this bike steady through tight turns and hard braking. Endurance geo means more of an arcing turn and less immediate initiation—for better or worse, depending on your preference—and the carbon bars mean even more stiffness, especially when diving into a turn in the drops and hammering out. The Trek Domane 6.9 DiscfeaturesShimano BR785 brakes which are not noticeably better or worse than Ultegra, but lack the IceTech cooling fins on the caliper (on the RS785 version) which could mean diminished performance on longer, sustained descents like you might find in the West. And the IsoSpeed Decoupler helps take the sting out of hard bumps in the rear.

Components: Drivetrain, Shifting and Brakes   
Usually I have a fairly easy time differentiating between similar groupsets like Dura Ace and Ultegra, but in the case of the latest iteration of Di2, the difference is nearly unnoticeable. Except in the wallet. The weight difference is negligible for all but the most serious gram counters—around 200 grams extra on the Ultegra. And the performance is even closer: Ultegra shares the incredibly smooth, quiet shifting and game-changing brake performance. While modulation might be slightly better on DA, overall stopping power is similar, and both generally use Shimano’s IceTech rotors, which help shed heat. Unfortunately the Shimano RS785 set on this bike lacks Shimano’s IceTech fins. There’s precious little difference in shifter levers too, both sharing ergo carbon levers with convenient reach adjustments. All this for around $1000 less.  

Wheelset
As mentioned above, the wheelset on the Trek Domane 6.9 Discis not as high end as we’d like to see at this price point. Other bikes feature carbon rims and often aero profiles, but the Affinity Elite—while a perfectly good all-around wheelset—is neither, and it’s not even Bontrager’s best Affinity wheel. It’s light enough and stiff enough for decent performance in varied riding conditions, but not stiff enough for heavy power output and not light enough to be an outstanding climber or sprinter. On the bright side, it’s tubeless ready and comes with everything you need to go tubeless.

Value
While cost is not the only factor in value, high price should mean minimal trade-off (if any), and for the most part the Trek Domane 6.9 Disc accomplishes this. But not quite. Again the wheels are definitely a compromise, and the DA addition simply drives up cost too much for the benefits. At $1000 cheaper, with Ultegra and a better wheelset and this would be the best in the test. But for $8k we think you can get a better value elsewhere.