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An endurance road bike with a truly innovative frame design...

New week, new bike... just arrived here at the road.cc HQ is the Trek Domane 2.3, a £1,200 endurance bike designed to offer plenty of comfort.

The Domane (pronounced doh-mah-knee) bikes, introduced last year, feature Trek’s innovative new IsoSpeed technology. You might remember that we reported on this when it was first launched. To explain it in Trek’s own words:

IsoSpeed isolates the seat tube from the rest of the frameset, doubling compliance and comfort with zero performance drawbacks.

How do they manage that? They use an IsoSpeed decoupler, of course. Essentially, the seat tube is no longer attached rigidly to the top tube or the seatstays so it is free to pivot back and forth. 

The idea is that you get more of our good old friend vertical compliance to increase your comfort and reduce fatigue. It’s designed to keep your rear wheel in better contact with rough roads too, rather than skittering and bouncing up, so you get improved traction. Trek also reckon that it’s laterally stiffer than their Madone.

Clearly, that’s a bonus if you’re hitting the cobbles of Flanders or Paris-Roubaix. If you’ve ever ridden the pavé you’ll know that anything that can help smooth the road surface has to be good news. But this bike isn’t intended just for rough roads, it’s also intended to add comfort on long rides without sacrificing efficiency.

So, there you go, that’s the IsoSpeed system. We’ll go into it in a bit more detail when we write our review.

Although the higher end Domanes are built around carbon-fibre frames, the 2 Series bikes – the most affordable ones – are aluminium. That’s Trek’s 200 Series Alpha Aluminium.

The frame is built to Trek’s Endurance geometry which means that the top tube is a little shorter than you get on Trek’s standard road bikes (even compared to their fairly relaxed H2 fit) and the head tube is a touch longer. The differences aren’t massive but you’ll get a slightly more upright ride position on a Domane.

Trek also build in more stability by increasing the length of the chainstays and adding more fork offset to extend the wheelbase, and by increasing the bottom bracket drop. A couple more frameset features worth noting are that the Domane comes with mounts for full mudguards and that the carbon legged fork is SpeedTrap compatible – you can mount a computer sensor inside the fork rather than having one stick out on the side.

The key groupset components come mostly from Shimano’s mid-level 105 range – the shifters, mechs and brakes are all 105. If you’ve been hanging out at road.cc for long you’ll know that we’re big fans of 105. It delivers an excellent level of performance for the money. The chainset is a non-series Shimano R565 with 50/34-tooth chainrings and the only other downgrade is the 12-30-tooth Tiagra cassette.

Most of the other components come from Trek’s in-house Bontrager brand, including the shallow drop VR-C bars and the carbon seatpost.

The Domane 2.3 is available in seven different sizes ranging from 50cm right up to 62cm. That one comes with a maximum seat height of 87cm. We have a 58cm model here and it weighs in at 9.27kg (20.4lb), and now we’re heading out the door to find out how that IsoSpeed technology performs on the road. We’ll let you know soon.

Mat has worked for loads of bike magazines over the past 20 years, and been editor of 220 Triathlon and Cycling Plus. He's been road.cc technical editor for seven years, testing bikes, fettling the latest kit, and trying out the most up-to-the-minute clothing. We send him off around the world to get all the news from launches and shows too. He has won his category in Ironman UK 70.3 and finished on the podium in both marathons he has run. Mat is a Cambridge graduate who did a post-grad in magazine journalism, and he is a past winner of the Cycling Media Award for Specialist Online Writer.

15 comments

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Matthewjb [75 posts] 3 years ago
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Quote:

Trek reckon that the Domane design offers 35mm of give at the back end.

Really? Or should that be 3.5mm?

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jackh [121 posts] 3 years ago
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Seems very competitively priced at £1200 with 105, I wonder if the aluminium frame lives up to the carbon offering.

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andyspaceman [246 posts] 3 years ago
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That's a lot of travel to build into an essentially rigid structure, but I can believe it.

What interests me is the particular alloy they've used for this application. Obviously steel and titanium have a much higher elasticity than aluminium, with the latter (in it's raw form) tending to fail much more readily when frequently flexed to material limits at a given point.

I've ridden high end scandium frames that have as much 'give' in them as good steel offerings. I wonder if Trek have had to use a specialist alloy for this frame in comparison with other offerings at this price point, or whether the flex is distributed widely enough throughout the frameset to ensure that maximum movement is well within the limits of their widely-used alloys?

Trek know what they are doing better than most, so I don't doubt that it's safe.

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CliveB [15 posts] 3 years ago
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Will 28c tyres fit in there?

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Mat Brett [626 posts] 3 years ago
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CliveB wrote:

Will 28c tyres fit in there?

Yeah, I think so. 25s fit easily. 28s with mudguards? Not sure. We'll try to remember to check this out before we run the review.

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Kapelmuur [335 posts] 3 years ago
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With regard to worries about the aluminium frame suffering stress failures, don't Trek offer a lifetime guarantee on the frame?

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BigDummy [314 posts] 3 years ago
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Pleeeeeeeease can you do a Domane -vs- Softride head-to-head test?

 36

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TrekBikesUK [128 posts] 3 years ago
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Nope. That's not a typo. It's 35mm.

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TrekBikesUK [128 posts] 3 years ago
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Hi Spaceman,

The key component of this frame is the weld beneath the decoupler. There were several test iterations of this frame, and we found that the placement of that weld there was vital to achieve both the compliance we expected from the frame, and the fatigue life we needed to ensure. It wasn't necessarily a matter of completely changing the alloy composition.

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TrekBikesUK [128 posts] 3 years ago
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Hi Crosshouses,

Yes, we do indeed offer a lifetime warranty on the frame.

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stealth [254 posts] 3 years ago
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Flexi-Aluminium??? For god's sake! 12 stone of mamil perched on top of a 1metre long stick that can flex by 35mm sounds like a recipe for disaster to me! Certainly wouldn't buy a 2nd hand one.
Just a technical point but vertical compliance could only be measured at the back wheel or saddle, what I should imagine this frame has is longitudinal compliance as I cannot see a suspension seat-post...
Sorry to be picky

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Mat Brett [626 posts] 3 years ago
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stealth wrote:

Just a technical point but vertical compliance could only be measured at the back wheel or saddle, what I should imagine this frame has is longitudinal compliance as I cannot see a suspension seat-post...
Sorry to be picky

Be as picky as you like, the saddle moves backwards and down.

From Trek: "Trek engineers designed a decoupler that allows the seat tube to rotate independently from the top-tube-to-seatstay junction, increasing vertical compliance to twice that of our nearest competitor, without compromising pedaling efficiency."

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Jon [33 posts] 3 years ago
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I share stealth's concern - if it's aluminium alloy, fixed to the bottom bracket at the bottom and can move 35mm at the top, how is that not a recipe for metal fatigue? Or does it flex along the whole length of the tube so the stress is well distributed? I can see the bulge of the weld near the top but a long enough seatpost would remove any flex from this section.

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Chris S [44 posts] 3 years ago
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Sorry to be late on this discussion, but you need to look at how the frame overall behaves, not just the seat tube/top tube joint. With a metal/'rubber' joint at the top tube/seat post, when the bike goes over a bump, the back wheel moves up, the rider tries to move down. So his/her weight now applies load at the bottom bracket rather than the top tube (depending just how flexible the rubber in the sandwich is). So the down tube/rear fork sags, and the top tube/chainstays move up relative to the seat post and put the rubber in shear. The critical aspects of the design are, how good is the bond between the rubber and the metal, or paint if the frame is painted before the rubber is bonded in, and how strong is the rubber when loaded in shear. I have ignored the fore/aft movement of the seat tube relative to the top tube, as this is a secondary effect. End of stress engineering lecture!

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cllr hodgen [41 posts] 3 years ago
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"Real world version of Fabian Cancellara's favourite bike"  39 39

... as he's given them for free & paid to ride!  13 4