Trek Emonda SLR Disc Project One review

When Trek launched its first Émonda SLR, just prior to the start of the 2014 Tour de France in Yorkshire, it was at
the time the lightest production road bike in the world.

Since then much has changed in the bike industry, starting with the introduction of disc brakes, and so too has the Trek Émonda. 

The first thing to mention is the weight. It was a pretty big deal for the manufacturer to go sub-700g (690g) for a production road frame back in 2014, so it’s an even bigger deal that this disc brake frame comes in substantially lighter at a claimed 665g for a U5 Vapour Coat-painted (Trek’s 5g paint finish) 56cm frame.

As a side note, the new SLR rim brake frame is a further 25g lighter at a claimed 640g. 

I’ve not pulled it to bits to verify the weight, but the complete bike with the latest Dura-Ace Di2 9170 hydraulic disc groupset and Bontrager’s Aeolus 3 TLR D3 wheels and carbon Bontrager finishing kit graced the Cyclist scales at a feathery 6.65kg, so there’s no reason to distrust Trek’s figures. 

That’s the lightest production disc road bike we’ve had through our doors so far, and by a good margin too, beating even the Cannondale SuperSix Evo Disc with Sram’s Red eTap hydraulic disc set-up at 6.90kg.

It means Trek’s pro team riders could happily flirt with the UCI minimum weight limit, even with disc brakes.

New beginnings

The previous Émonda SLR was a bike I rated very highly, being not only light but also an incredibly good ride.

If you were looking for a bike with an aggressive race geometry that flies up hills and feels stable yet nimble on the way back down, it was a bike I often recommended (I get asked this question a lot). 

Since the leap to disc brakes, though, the landscape has changed. Many bikes I thought were great in their rim brake guise disappointed on some level once discs were added.

Apart from perhaps the aforementioned Cannondale and also Specialized’s Tarmac Disc, few have left a really positive impression. 

That’s because keeping the weight down is only part of the challenge. The best bikes are those that can trim the fat while maintaining sublime handling, responsiveness and sufficient comfort too.

And that’s exactly what Trek’s director of road, Ben Coates, suggests has been the primary target with the latest 700 OCLV carbon lay-up developed specifically for the new Émonda. 

‘For this bike we changed absolutely everything and made improvements across the board. It was a new start from the ground up,’ he tells Cyclist.

‘We’ve evolved it, finding new fibres and ways to improve the laminate schedule, and the carbon fibre pieces are even smaller and more precise – optimised for the jobs they have to do.’ 

The result, according to the data, is a frame that’s stiffer in all the key places – bottom bracket and head tube especially – while also being more vertically compliant.

Of course, we’re not just going to take Trek’s word for that, and I was fortunate to be able to fully test the new Émonda just days after its official launch, at the week-long Haute Route Rockies event in Colorado.    

The toughest test

It doesn’t take long in Colorado before you find yourself on a dirt road, and one of the first things that struck me with the Émonda SLR was the high level of comfort.

A combination of 28mm tyres inflated to 80psi, the appreciable flex in the seatmast and a frame that was capable of taking the edge off the road shocks meant it was as much a pleasure to push hard across the gravel stretches as it was the smoother tarmac. 

That’s a huge boon for a bike at this weight. It was never skittish on loose surfaces and offered precise feedback through the front end to guide it at high speeds through the many hairpins I encountered on both dirt and paved descents, plus a rather panicked avoidance of a scampering marmot while at full tilt. 

Climbing always forms a hefty chunk of every ride in the Rockies, and if you’re not properly acclimatised the altitude can quickly sap energy.

That’s when you appreciate every bit of help, and the Émonda did a great job of preserving my precious watts.

It felt extremely taut in its lower half as I laboured to the summit of many 3,000m peaks (and one above 4,000m), with no hint of anything being lost to flex – whether I was grinding my way upwards seated or dancing out of the saddle. 

Any gripes I had were minor. The seat tube bottle cage is a little too high up, which not only raises the bike’s centre of gravity but also means it’s a fight to get a 750ml bottle in and out around the top tube. 

I’d have liked removable thru-axle levers to clean up the fork dropout, and I feel the cabling is a bit messy.

I appreciate that Trek has not internalised the front brake hose in the fork leg in order to save weight, but with Bontrager as an in-house brand it’s surprising that the company hasn’t developed a handlebar specifically
to make the most of the latest Di2 junction box and charge port encapsulated within the bar plug.

This would eradicate the unsightly under-stem box. But none of these issues really undermines what is a truly outstanding machine.

At the time of writing I haven't had the chance to ride the Émonda SLR Disc Project One much on my local routes, but if I feel like a bit of Strava chasing in the coming days and weeks, I know for sure which bike I’ll be reaching for.

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