Trek Domane SL6 review

IsoSpeed front- and rear-equipped sportive bike that's one of our Endurance Bike of the Year 2020 contenders

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Our rating 
4.0 out of 5 star rating 4.0
GBP £3,200.00 RRP | USD $3,800.00 | EUR €3,599.00 | AUD $5,000.00
Trek Domane SL6 red road bike

Our review

Versatile, quick, and very smooth endurance machine
Pros: Ride quality, assured handling, smoothness throughout
Cons: It carries a bit more weight than its rivals
Skip to view product specifications

For 2020, the Trek Domane’s front and rear IsoSpeed suspension-equipped chassis has undergone a major overhaul. It’s lost a little weight, gained further aero shaping and, now that the design is disc specific, it’s opened up tyre clearance to a massive 38c size.

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The geometry’s been tweaked too, to a short reach at 380mm, with a mid-height 611mm stack for a 58cm-sized endurance bike.

What hasn’t changed, though, is the key to the Domane’s continued success – its palmarès includes wins at Paris-Roubaix and the Tour of Flanders – and that’s the quality of the ride.

Bike of the Year 2020

The Trek Domane SL6 is part of our annual Bike of the Year test.

Head to our Bike of the Year hub for the full list of winners, categories and shortlisted bikes, as well as the latest reviews – or read our behind-the-scenes feature on how we tested Bike of the Year 2020.

Trek Domane SL6 03
The Domane SL6’s IsoSpeed decoupler.
David Caudery / Immediate Media

Trek Domane SL6  frame

At the heart of this is its IsoSpeed decoupler. Simply put, it maintains the diamond-shaped geometry but ‘decouples’ the seat tube from the top tube, allowing the seat tube to flex with the lay of the road.

Trek has done a great job in reshaping the Domane and the bike now looks super-clean with little in the way of exposed cables anywhere, adding to the aerodynamic appeal.

Trek Domane SL6
The bike has a clean look with the front-end cables routed under the bar and through the frame.
David Caudery / Immediate Media

The front-end routes the cables under the bar and stem and around the steerer tube, entering the frame just behind the head tube in a similar fashion to how Cervélo routes cables on its long running S-Series aero bikes.

The new Domane frame also includes quite a neat little surprise under the down-tube bottle bosses. There you’ll find a compartment with a quick-release lever with enough space to store a spare tube, C02 cartridge and multi-tool. Inside there’s also a custom-sized tool wrap to stop any rattles or shakes.

It’s a neat idea and one I really like because it keeps your jersey pockets free of stuff and the bike looks cleaner without a grubby, mud-splattered saddle pack.

Trek Domane SL6
This neat little compartment should lighten the load on your jersey.
David Caudery / Immediate Media

Trek Domane SL6 kit

Trek’s choice to specify 32mm tyres is certainly at odds with most endurance bikes and elevates overall weight to the 9.5kg mark, which is more in line with a gravel bike than a road-ready rig.

However, the SL6 doesn’t feel heavy when you’re riding it and the R2 tyres are impressive, featuring durable all-weather tread and hard-case protection that covers the roughest ground smoothly – everything from roughly chipped tarmac to frost scarred lanes and even light gravel – which makes up for carrying a few hundred extra grams over its rivals.

I’ve been impressed by their grip and puncture protection too, during plenty of winter test miles.

They sit well (and wide) on the Paradigm Comp 25 wheels. The Paradigms have an alloy rim that’s seriously broad at 25mm wide internally, which shapes the R2 tyres with a smooth, constant radius that boosts confidence when cornering.

Those wheels are beautifully put together with a build comprising serviceable brass nipples that hold the aero-bladed spokes in place, while the Rapid-drive, 54-tooth rear picks up quickly and spins smoothly. At 1,775g, they’re not the lightest wheels but they’re damn tough.

Trek Domane SL6
Shimano Ultegra with 50/34 gearing and a wide 11-34 cassette.
David Caudery / Immediate Media

Unfortunately, unlike the Paradigm wheels, the tyres aren’t tubeless-compatible, so should you want to get the benefits of an inner tube-free ride, more versatility on tyre pressure, the elimination of pinch punctures and an ever-widening range of tyre options in the larger sizes the Domane can handle, you’ll need to replace them.

Just like pretty much every bike out there in this price range, Ultegra is the order of the day and the kind-to-your-knees 50/34 gearing is matched to a wide 11-34 cassette.

This equipped me with a low enough gear to attack the steepest of inclines knowing that a one-to-one bottom gear was there in reserve.

Trek Domane SL6
Bontrager’s Arvada Comp saddle.
David Caudery / Immediate Media

Trek Domane SL6 ride impressions

In an ideal world, the Domane would be a little lighter because it doesn’t share the same sprightly upward momentum as its lightweight endurance rivals, such as Canyon’s Endurace or Cannondale’s Synapse, but it boils down to a trade-off between class-leading comfort or climbing prowess.

Downhill, though, the Domane is a supreme partner. The IsoSpeed-equipped chassis sits down and grips where plenty of bikes can skit and skip across the road surface, especially when the surface is less than ideal.

Trek Domane SL6
The Domane feels stable and is good place to be on longer rides.
David Caudery / Immediate Media

Paired with excellent Ultegra brakes and Ice-tech rotors, the SL6 is one of the most enjoyable descending companions out there.

The Domane’s handling feels very stable and, despite that short 380mm reach and mid-height 611mm stack, doesn’t feel cramped or particularly upright or pedestrian. It’s just a very good place to spend lots of hours in the saddle.

Trek Domane SL6 overall

The SL6 has a huge amount going for it. The ride quality never fails to impress and it handles with assured stability without being dull.

If I was looking for a bike for a big challenge on sub-optimal roads then the Domane would be the first bike on that shortlist.

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Trek Domane SL6 geometry

  • Sizes (* tested): 44, 47, 50, 52, 54, 56, 58*, 60, 62cm
  • Seat angle: 73 degrees
  • Head angle: 72 degrees
  • Chainstay: 42.5cm
  • Seat tube: 54.8cm
  • Top tube: 56.7cm
  • Head tube: 19.5cm
  • Fork offset: 4.8cm
  • Trail: 6cm
  • Bottom bracket drop: 7.8cm
  • Wheelbase: 1,022mm
  • Stack: 61.1cm
  • Reach: 38cm

With thanks to…

BikeRadar would like to thank 100%, Q36.5, Lazer, Garmin and Facom for their support during our Bike of the Year test.

Product Specifications

Product

Price AUD $5000.00EUR €3599.00GBP £3200.00USD $3800.00
Weight 9.53kg (58cm)
Brand Trek

Features

Available sizes 44, 47, 50, 52, 54, 56, 58, 60, 62cm
Handlebar Bontrager Elite Isozone VR-CF
Tyres Bontrager R2 hard case lite 32mm
Stem Bontrager Blendr
Shifter Shimano Ultegra
Seatpost Domane carbon
Saddle Bontrager Arvada comp
Rear derailleur Shimano Ultegra
Front derailleur Shimano Ultegra braze-on
Bottom bracket Praxis
Frame OCLV 500 series carbon
Fork OCLV 500 series carbon
Cranks Shimano Ultegra, 50/34
Chain Shimano Ultegra
Cassette Shimano Ultegra, 11-34
Brakes Shimano Ultegra hydraulic disc, 160mm rotors
Wheels Bontrager Paradigm Comp 25