Trek Domane SLR 9 2020 review

The original Domane redefined the endurance road sector. Trek’s innovative IsoSpeed concept – a pivoting decoupler that isolates seat tube flex from the rest of the frame to offer more vertical compliance without impairing rigidity elsewhere – broke new ground on its release in 2012.

The resulting marriage of outstanding comfort and race-level performance helped Fabian Cancellara win the punishing Strade Bianche race on the bike’s first professional outing.

In 2016, Trek brought adjustability to the rear IsoSpeed and employed a similar ‘decoupling’ ideology to the head tube to temper impacts up front, too. Again it received high praise, including in my own review in issue 52 [see page 2 of this review]. This third generation 2020 version, then, has a lot to live up to.

New directions

‘We’ve really seen big changes in the way people ride road bikes,’ says Trek’s director of product for road bikes, Jordan Roessingh. ‘They want to ride on a variety of surfaces so we’ve really embraced that, focussing on versatility and making sure the rider can do as much as possible on this bike.’

To that end, there are a number of new features on the Domane SLR. Firstly, it now shares the same L-shaped, top tube-braced IsoSpeed as used on the most recent Madone, the company’s aero race bike.

This is an improvement because it not only offers more comfort, but is also easier to adjust. I also prefer its higher position on the bike, well away from the grit and filth flung from the rear tyre.

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Trek claims the new IsoSpeed gives the Domane SLR 27% more rear-end compliance. To give that some context, that would make the new frame almost as compliant in its firmest setting as the outgoing model was in its softest.

I think that figure is over-inflated, and oddly I’d say I found the latest Madone a touch plusher when comparing the models in the softest setting. That’s not to say the Domane isn’t a very comfortable bike. It feels slightly less adept at dealing with small-amplitude impacts compared to the older model, but still absorbs larger hits exceptionally well.

Buy the Trek Domane SLR 9 from Trek for £8,750

Trek has also added a modicum of rebound-damping into the new IsoSpeed system, which makes it feel more controlled and less bouncy, although one gripe I have is the way the nose of the saddle can tilt up as the seat tube flexes.

It’s less noticeable in the firmest setting, but at the other end of the scale I found there was a persistent prodding at my nether regions. This can be overcome by setting the nose of the saddle down a fraction, but it’s something to be aware of.

The front IsoSpeed, which is unchanged from the previous iteration, continues to serve the Domane well. It’s just enough to take the edge off jarring impacts and, with assistance from Bontrager’s vibration-damping IsoCore carbon handlebars, the front end feels acceptably smooth.

Importantly, the comfort doesn’t come at the expense of performance. In fact the latest Domane has upped its game in terms of speed.

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‘Everyone wants to go fast, regardless of how they ride, so there is a much greater aero emphasis for this new frame,’ says Roessingh. ‘It’s certainly not fully optimised like the Madone, but we’ve made some pretty big improvements at “real-world” speeds [30-35kmh].’

Trek hasn’t quantified those aero gains, and I can’t provide any hard evidence, but I can say this new frame, aided by Bontrager’s excellent Aeolus XXX 4 wheels, offered a noticeable step up in terms of pace over my regular test routes.

I was sufficiently impressed with the bike’s race credentials to consider whether it was beginning to encroach into the Madone’s territory. Ultimately it doesn’t quite, but what was once a very distinct line between them in performance terms is getting blurrier.

Of course, the Domane is still the more upright choice, based around Trek’s ‘endurance fit’, which allows even my creaky old spine to run with a slammed stem.

Tyred out

One feature that clearly sets the Domane apart from the Madone is its tyre clearance. Despite this test bike coming with relatively skinny 25mm tyres, the new Domane has room for some fairly beefy rubber, Trek suggesting up to 38mm.

It could potentially take even wider tyres if you ignore Trek’s advice to maintain 4mm of space around the tyre, and there’s no issue pairing wide (32-35mm) tyres with full-length mudguards, for which the Domane has some neatly concealed mounts.

It’s all part of the versatility that Roessingh talked about, and we haven’t even got to the Domane’s most unique feature yet…

Called BITS – Bontrager Integrated Tool Storage (thank goodness they didn’t call it Trek Integrated Tool Storage) – it’s a compartment in the down tube accessed via a quick-release cover, onto which the water bottle cage mounts. Inside is a purpose-designed pouch providing stowage for an inner tube, tyre levers, CO2 canister with head and a multitool, plus by my reckoning there’s also room to stuff an emergency gilet in there.

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It’s a nice idea, allowing the rider to avoid over-stuffed jersey pockets, but I do have some concerns about it. The cover is not a totally locked-in fit and with a full water bottle and cage mounted to it there is visible movement as you ride, particularly on imperfect surfaces. It didn’t actually rattle during my test rides, but my worry is that over time it will wear and will inevitably start rattling in the frame.

‘There will be a little bit of relative movement between the cover and the frame with a full bottle but we don’t expect the cover to get loose over time,’ Roessingh says. ‘In the case that something did go wrong, though, we do stock replacement covers and it’s a relatively easy piece to replace.’

Trek did send me a new cover and it was slightly better, but some clearly visible movement remained. It’s not a big problem, but I found myself wondering how I would feel if I had bought a new Porsche and discovered the glovebox wobbled. Should I accept it on a bike costing nearly £10k?

It’s a small blemish on an otherwise shining example of how good and how versatile the Domane platform continues to be. So I congratulate Trek for its innovation, which is, after all, what made the Domane such a success in the first place.

Buy the Trek Domane SLR 9 from Trek for £8,750

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Spec

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Trek Domane SLR 9 2016 review

The original Trek Domane was a bold move that has stood the test of time, but what does this audacious revamp have in store?

Remember twanging rulers on desks at school? The shatterproof plastic ones were best. You could create some great comedy noises, altering the pitch by how far along you held it and even sliding it mid-twang for a different kind of sound altogether.

Why, you might ask, am I wittering on about schoolboy classroom antics? Well, oddly that’s what comes to mind when I think of describing the way Trek has designed the seat tube of its new Domane in order to offer tuneable comfort. 

For the record it doesn’t make any twangy noises, but the seat tube is split in two below the IsoSpeed decoupler (where the seat tube bisects the top tube), with a movable wedge sandwiched in between. Loosening the clamp bolt, which also doubles as one of the bottle cage mounts, allows you to reposition the wedge further up or further down the seat tube, effectively altering the anchor point according to your comfort requirements. At its lowest fixed point – nearest the bottom bracket shell – you get the maximum vertical compliance, like having more of the ruler overhanging the desk. Trek claims this provides 14% more vertical flex than the old Domane. Slide it all the way to the top and you get a noticeably less forgiving back end.

Softly softly

Having tested two previous versions of the Domane myself – the original release and the disc brake version - I’m in a strong position to assess this new design and make direct comparisons. I would start by contesting whether the new design is only 14% more vertically compliant. I would have said it was at least 20% better. It’s a visible difference to the old Domane, and when you’re in the saddle and hammering over rough ground it’s an appreciable benefit that’s a real boon for this new bike.

Everything from even the slightest road buzz feels better dissipated, but it’s the really big thuds where I was truly wowed. Hit a sharp-edged crease in the road surface or a speed bump at pace and you can feel the seat tube flex beneath you when on the softest setting.

The difference between the two extremes is really noticeable, and I’d agree that you can set this new bike stiffer than the old model. And of course you have everything in between to fine-tune to your heart’s content. I even kept a 4mm hex (with preset 5Nm torque key) in my jersey pocket on some rides to be able to quickly pull over and make a change, which, since you ask, takes only a matter of seconds.

But I found myself wondering – why bother? I’d put the wedge into a firmer setting and pedal off, but no sooner had I noticed the stiffer sensation than I would be inclined to stop again and switch it back to the softer end of the scale. The reason is simple: why pass up the chance to have a lovely smooth and comfy ride feel when there seems like absolutely no real downside to running in such a soft setting? While Trek claims the stiffer setting marginally preserves power, it doesn’t feel squidgy, like you’re sat on an exercise ball, and as I said, you only really notice it working when you’re thankful for it. All the while, pedalling performance seems to be almost entirely unaffected. It’s a real triumph in terms of design. 

OK, the Domane doesn’t whip up to speed quite as quickly as the Emonda (Trek’s super-svelte racer) or whizz along with the poise of the Madone (Trek’s aero road beast) but it’s no slouch and I was never left wanting. Our 56cm test bike was a smidgen over 7kg, partly thanks to Sram’s super-light Red eTap wireless shifting, which was flawless throughout this test.

Bontrager’s Aeolus 3 D3 wheels are also superb, bringing another significant positive to the build, although it was disappointing that Trek didn’t see fit to make the most of their tubeless compatibility in that the bike came fitted with standard clinchers - I’ll come back to the tyres later. Overall, it’s hard to fault the Domane’s performance, especially given it leaves both its forebears out of sight in terms of comfort. 

Back to front

While all discussion thus far has been focused on the rear end, there’s a lot going on up front too. Where the old model was criticised (and I agree) for feeling disjointed, in that the front end comfort couldn’t match the compliance of the rear, Trek has really worked on a solution for this new bike.

The IsoSpeed decoupler that has proved so successful in facilitating only the desired amount of flex at the rear of the bike has been re-engineered slightly to apply the same ideology up front. 

In short, the decoupler at the front end cradles the upper headset bearing to allow the steerer tube to flex front to back while maintaining lateral support. I’ll start by saying it’s nowhere near as effective as the rear, so
there remains some disparity, plus its effectiveness does seem to be dependent on the stem length (a longer stem has a lot more leverage, so will flex the steerer tube more), but it’s a step in the right direction.

In any case I’m not sure I would want the bars to feel as fluid as the seat tube does, given the potentially disconcerting feel that could arise with too much movement. It’s already enough that the design means there’s always a slight sensation akin to the presence of a loose headset and the occasional audible clunk to get your head around.

However, it does take the sting out of impacts and the handlebars themselves add to the vibration-absorption with newly developed technology from Bontrager. The Pro Isocore bar has a thermoplastic elastomer layer sandwiched between the carbon layers, which it claims reduces vibration by 20%.

The combined effect of these two new features up front is a noticeable step up in comfort compared to the old Domane, but I feel this area still needs a little refinement. Just as the second generation of the bike’s rear has moved on for the better, I think Trek will gradually be able to improve how the front end reacts too, and who knows – maybe even make this user-adjustable at some point in the future too.

Trek recommends a maximum 28mm tyre width (fitted as standard), but I was able to squeeze in a 30mm Challenge Strada Biancha open tubular. Admittedly clearance was tight under the Bontrager direct-mount brakes, but it was acceptable for all but a horribly grubby ride where dirt did start to accumulate and rub.

Running with 30mm tyres at 85psi made this bike the closest thing I have ever experienced to the magic carpet ride that many manufacturers have touted in their marketing blurb but few, if any, have ever delivered. 

I don’t like – or agree – with the term ‘do it all’ bike (who only wants to own just one bike anyway?), but Trek has at least realigned my thinking a bit, and certainly sets the bar high with the new Domane. There wasn’t much this bike couldn’t do. I even rode it on rocky mountain walking trails in the Dolomites up to over 2,000m (which you can read about soon). As I write, industry rumours are afoot of a response from Specialized, most likely with a revamp of its renowned Roubaix model (as yet unconfirmed), but I think even ‘the Big S’ will have its work cut out to top this Domane.

Spec

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