Trek Domane 4.3 Disc review

1 Mar 2017

The Trek Domane 4.3 Disc is the future, and it only takes one ride for you to realise it

Cyclist Rating: 
Geometry is perfect
It is not a lightweight set up and will quickly be superseded

When Trek launched the Domane back in 2012, it was intended as a Classics season cobble gobbler, tailored to the talents of Trek’s superstar rider of the time Fabian Cancellara. With two Tour of Flanders wins and one at Paris-Roubaix, it clearly worked for him. But with the move to disc brakes, does it work for mere mortals too?

The frame

Where to start? Trek isn’t known for breaking moulds, but a quick glance at the Domane tells you this is no ordinary bike.

The big talking point of the Domane has always been the IsoSpeed decoupler, which allows the seatstays and seat tube to move independently of each other in the vertical and fore-aft planes.

Trek claims the system allows for as much as 35mm of compliance, perfect for rough roads, just like you get in the Classics.

In 2012, when the Domane was first released, IsoSpeed was a pretty out-there concept. But now, with bikes like the Giant Defy and Cannondale Synapse, compliance is less of a USP.

What is unique is the Domane’s geometry. The lower the bottom bracket is, the more stable the bike feels, and while we’re used to seeing bottom bracket drops (the distance the centre of the BB is below the wheel axles) of around 70mm, the Domane has a huge 80mm of drop – in fact, we measured it at 82mm on our size 54.

That translates to a feeling of riding low between the wheels, and huge cornering confidence. Compounding this measurement is the wheelbase which at over 100cm, is huge for a 54cm bike.

Again, more length equals greater stability, and more room for manoeuvre when speeds go up, or you start getting tired. Add bolt-thru hubs front and rear to increase lateral stiffness, and you’ve got a bike that handles like no other road bike we’ve ever ridden, with pin-point precision downhill.

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Have we told you how much we like Shimano’s 11-speed 105? Shame Shimano doesn’t make hydraulic brakes at 105 level – Trek has gone for the Hy/Rd, which use cables to actuate a hydraulic calliper.

Those callipers end up a bit bulky as a result but they work, and offer a good compromise – braking power that’s not quite as full-on as full hydraulics, but definitely more powerful than cable discs.

The Bontrager finishing kit is all good gear, including the carbon seatpost, but the 90mm stem is a little short for us and the bars an odd shape with more reach than most.


One of only two bikes on test with bolt-thru axles, we’re definitely of the opinion that they’re a good thing, keeping the brake rotors in just the right place between the pads to stop rubbing. But jeez, are they ugly.

The wind-up ratchet axles on the Saracen are tiny compared to the quick-release levers used here – yes, you flip a lever and then unwind the whole axle. This is a design that has come direct from mountain bikes and in this application, seems like overkill.

The Bontrager wheels are tubeless-ready and a decent everyday wheelset, as are the R1 Hard-Case tyres – you’ll want to upgrade to something lighter, more supple and grippier eventually, but these are a decent start.

The ride

We like to talk a lot about numbers at Cyclist, and while that could be perceived as boring, it really does inform what you’re able to feel on the road. As soon as we saw the Domane’s geometry we were excited to see just how fast we could corner on it.

The long, low-slung layout of the bike is incredibly forgiving – a world away from skittish, fast-handling race bikes that need to be tamed by a steady pair of hands.

The IsoSpeed definitely works and takes the edge off big hits and road buzz, but don’t expect an armchair ride – the Domane is still very much a road bike with efficiency and power transfer at its core.

And despite being mid-pack when it came to weight, we didn’t feel the Domane was sluggish once up to speed – in fact, the stiff bottom bracket area really encourages you to jump out of the saddle and sprint.

We had doubts about the TRP Hy/Rd brakes but the combination of comfortable 105 shifters and powerful but controllable hydraulic braking actually proved an unexpected hit.

It’s not a lightweight set-up and technologically, it’s likely to be superseded in the next year or two, but for the moment, it’s a good compromise. As we discussed in the introduction, we came into this test with an open mind, looking to see what is possible when you combine disc brakes and road bikes.

With the Domane Disc, Trek has produced a bike that genuinely breaks the mould and rides faster, and with more confidence than any rim-braked road bike we’ve tested. Is the Domane a glimpse of the future? We think so.

Frame - Long wheelbase + very low bottom bracket = the future - 10/10
Components - Nice mix of Shimano, TRP and Bontrager kit - 8/10
Wheels - Decent tubeless-ready wheels with bolt-thru axles - 8/10
The ride - A fast, exciting mould-breaking ride - 9/10


Geometry chart
Claimed Measured
Top Tube (TT) 542mm 538mm
Seat Tube (ST) 500mm 505mm
Down Tube (DT) 604mm
Fork Length (FL) 382mm
Head Tube (HT) 160mm 160mm
Head Angle (HA) 71.3° 71.3°
Seat Angle (SA) 73.7° 73.4°
Wheelbase (WB) 1,010mm 1,015mm
BB drop (BB) 80mm 82mm


Trek Domane 4.3 disc

400 Series OCLV Carbon, IsoSpeed, Trek IsoSpeed carbon disc fork with 15mm bolt-thru axle


Shimano 105


TRP Hy/Rd cable/hydro disc


Shimano RS500, 50/34


Shimano 105, 11-32


Bontrager Race Blade VR-C


Bontrager Race Lite


Bontrager Carbon


Bontrager Tubeless Ready disc


Bontrager R1 Hard-Case Lite 25mm


Bontrager Paradigm 1



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