Announced in March for the Classics, the Trek Domane 6-Series carbon endurance road bike line increased with 5-, 4- and 2-series models recently.
Aimed at the cobblestone races in Europe, the Domane uses a unique IsoSpeed Decoupler at the seat tube/top tube junction to separate the rider from bumps. Up front, the IsoSpeed fork uses thinner legs with rearward-set dropouts to absorb vibrations and bumps without sacrificing steering precision. Combined, they do an admirable job of smoothing out rough roads, gravel paths and cracks in the pavement.
We borrowed a Project One build from our local Trek Store Greensboro (thanks Chris!) for a few rides. While we had it, we also de-coupled the decoupler just to see what was inside, weighed it and put about 150 miles on it in both rain and blazing heat…
FRAME DETAILS
We tested a size 60 with a complete Bontrager cockpit, saddle, tires and Aeolus5 aero wheels with Dura-Ace Di2 (first gen). It also came equipped with the DuoTrap speed/cadence sensor and a rather nice Bontrager computer.
The Domane’s frame is big. For a bike that claims to be comfortable over the rough stuff, all of the tubes have substantial diameters and shaping that looks to favor stiffness over flex. Indeed, the entire lower half of the bike from the head tube through the downtube/BB/chainstays to the rear dropouts is called Power Transfer Construction and is designed to maximize, um, power transfer and keep the frame laterally stiff.
Part of the stiffness, and, we suspect, steering precision, comes from the ridges and shaping of the down- and top tubes combined with the tapered headtube. What you can’t see is Trek’s E2 asymmetric steerer tube, which is wider side-to-side than front to back. The frame is the same whether you’re running a mechanical or electronic drivetrain, you simply use different plugs.
Bottom bracket is PF92, which is essentially the widest internal bearing set up you’ll find. Non-driveside crank arm sits flush against the frame, and the seat tube comes all the way to the edge. On the driveside, there’s room for the front derailleur and Trek’s built-in chainguide.
Behind the BB is a small fender mount bolt. The ANT+ DuoTrap speed/cadence sensor is cleverly integrated into the chainstay.
At the back, small fender/rack bolts are all but invisible. These debuted on the Gary Fisher road bikes and we’re glad to see they’ve continued on. A large opening at the rear of the chainstay makes routing cables and wires to the rear derailleur easy.
At the heart of the Domane’s USP is the IsoSpeed Decoupler. The top tube splits just in front of the seat tube and continues around it to become the seat stays. The seat tube floats between them, pivoting on an axle:
Remove the cover (top left) and you’ll see two sealed cartridge bearings (top right, bottom left), which separate the frame from the axle. The axle serves as a pivot point for the seat tube, which allows it to essentially act as a leaf spring. Combine that with a good amount of flex built into the seatmast and seat stays and you have the makings of a very comfy bike. Here, we made a video:
Pedaling is intentionally high cadence with an exaggerated bounce. The first part of the video really shows the seatmast flex. Once it zooms in, you can notice subtle flex in the seat tube. Once pedaling stops and I bounce on it, notice the wide range of flex in both the seat tube and seat stays. Hit HD and full screen for best viewing results, and if you really wanna geek out, hold the edge of a paper inline with the seat tube and watch the magic happen.
Under normal pedaling in a cadence of 80-102rpm, my usual range, I didn’t feel any unwanted “bounce”. Get the cadence up a bit higher and you’ll notice it a bit, but it’s actually more pleasant than the usual bouncing up and down on the saddle that occurs when cadence gets abnormally high. Also note the lack of frame flex when I stand up and bounce, which is by design. There are no concessions for flex when the riders’ weight isn’t on the saddle. Except at the fork, it’ll do it’s job regardless.
ACTUAL WEIGHT
Actual weight is 15lbs 15oz on our scale with uncut steerer tube, computer and Bontrager XXL bottle cage. Pretty good considering a) it’s a size 60, b) it has aero wheels and c) it’s holding a two-bearing-equipped axle that no other road bike has.
RIDE REVIEWS
Tyler – I did four rides on the Domane – one 45 minute sprint interval workout, one 55 minute time trial in the rain and two normal rides, each about three hours. The sprint workout showed the bike could get up and go. It’s plenty stiff when you stand up and crank. It doesn’t feel as light and tight as a pure race bike, but it doesn’t really leave you wanting either.
On my rainy time trial, there were sections of John Anderson (part of the famous Loop ride) in Ormond Beach with an inch or so of standing water, which tend to hide that road’s abundant cracks and ridges. Where most bikes would keep a wider line away from the side of the road to avoid the chatter, the Domane plowed through rough patches seen and unseen without breaking stride. And I could absolutely power through it all, which, I like to imagine, is how Cancellara felt aboard the Domane training for this year’s Spring Classics (before he broke his collarbone).
There are three things I really like about the Domane. First, it perfectly smooths over any bump or crack under half an inch, and up to an inch is entirely manageable. Where a crit bike would skip and hop over every bump, requiring constant attention, the Domane lets you relax and just point it where you want to go. Second, you can rail into sketchy corners and maintain both traction and your desired line. Third, it just rides really well.
The result is a bike that I could ride fast all day, over any type of road, and still feel relatively fresh.
Colin – I only took the Trek out on one ride, a blistering hot 35 miler, and wish I had more time to get to know the bike better. But all in all, on a short ride, the first thing that’s noticed is the sponginess (in a good way) in ride quality. Trek’s IsoSpeed Technology in the seat tube absorbs bumps to a huge extent. There’s a serious “wow” factor on hitting potholes and such. Jarring terrain becomes very manageable. Although I was concerned of energy dissipation from this feature, I don’t feel like the frame robbed any of my power.
The Domane’s handling is relaxed and stable. It’s big, built for cobblestones, and handles that way. But I wouldn’t limit the Domane to pavé. When on the streets it rides the same as many road bikes while slightly more relaxed. Surprisingly light at sub-16lbs, I’m not sure what else I’d ask for in a weekend rider. Durability, stability, ability to ride on rough terrain, racy, light. Trek packs a ton of awesome features into the Domane that might make it a worthy investment even if you don’t race the Classics, particularly with the design already trickling down to models that should start well under two grand.
