Trek launch Domane SLR with front and rear IsoSpeed technology
Adjustable IsoSpeed offers 14 per cent improvement in comfort, according to Trek
Four years after the launch of the original Domane, Trek have introduced the Domane SLR, in both rim and disc brake versions. The SLR uses a second-generation IsoSpeed decoupler at the rear, while also introducing the comfort-boosting technology at the front of the bike, along with a new IsoCore handlebar.
Trek's road bike range is split into three clear divisions. With the super-light Emonda SLR launched in 2014, and the hyper-aero Madone coming in 2015, it's now the Domane's turn - but Trek's endurance bike has been overhauled, rather than simply updated. These are the headlines before we delve into the details and what Trek are saying about the new bike at the launch in Belgium.
- Rear IsoSpeed decoupler now adjustable, up to 14 per cent increase in compliance
- Front IsoSpeed introduced, claimed ten per cent improvement in compliance
- New IsoCore handlebar said to offer twenty per cent increase in vibration dampening over stock carbon 'bar
- Disc and rim brake versions, from £3,600 to £7,600
- 28mm tyre clearance on Domane SLR, 32mm on Domane SLR Disc
Back to the future
The original Domane was a genre-defining bike and one of the first in a new breed of endurance machines. The Tour of Flanders and Paris-Roubaix served as inspiration for the Domane, with Fabian Cancellara, who went on to win the Flanders-Roubaix double on the bike in 2013, as the test pilot.
If you're not familiar, the Domane 1.0 used a decoupler, dubbed IsoSpeed, to isolate the seattube from the toptube. It was a very smart piece of engineering, and undoubtedly an effective one - but its success was also, to some degree, its downfall, and gave Trek the impetus for the Domane SLR.
The Domane's plush rear end had a tendency to make the front feeler harsh; something Trek say they learned through press reviews and rider feedback. The Domane 2.0 concept was born, 33 ideas were brainstormed, and three frames, two forks and two handlebars fabricated before the production project was launched, and Trek's initial concepts were fine-tuned through a process of rider evaluations, structural testing and computer simulations to arrive at the Domane SLR.
Adjustable rear IsoSpeed
"Adjustable IsoSpeed really started when we were developing the original Domane," says Ben Coates, Trek's road bike product manager. "We developed a lot of different [carbon] laminates, a lot of different levels of compliance to test.
"We tested them with Fabian [Cancellara], we tested them with riders back in Waterloo [Trek HQ] and we tested them with other professional riders, and we found, in some instances, riders had different preferences. Fabian likes a really stiff bike, with a lot of compliance in it, while others riders on the team like a less stiff bike."
Trek say they've solved that problem by making the Domane's IsoSpeed decoupler adjustable. While at the seattube and toptube junction, the IsoSpeed decoupler looks similar to that on the original Domane, below it the seattube is effectively split into two. The rear is an extension of the seatmast, which effectively acts as a leaf-spring, and is connected to a fixed seattube by the pivoting IsoSpeed decoupler at the top and a bolt at the bottom, neatly integrated into the bottom bottle cage bolt. This allows the carbon blade to flex independently, with the slider used to adjust the level of fore-aft flex.
"You're using the seattube as the leverage point, just as you did in the original Domane, but now you have a level of adjustment," says Coates. "As you move the slider up, you reduce the compliance by using less of the seattube, and as you slide the slider down, you're increasing compliance by using more of the seattube."
The result, Trek say, is a 14 per cent increase in compliance compared to the original Domane, when the slider is on its lowest setting. "We found we were capable of having an adjustment range of over 30 per cent compliance - a range from Madone and Emonda-levels of compliance, all the way to 14 per cent more compliant than the original Domane," says Coates.
"That means that if you want a little more comfort out of your original Domane, you're going to get that here, or if you want it to be a little stiffer, you can still have all the other benefits of the Domane."
Those benefits include the front IsoSpeed, IsoCore handlebar and the Domane's endurance-focused geometry. All of which we'll come on to, but it's not all about comfort, of course - particularly on a bike ridden to victory on its race debut by Cancellara at the Strade Bianche earlier this year, and to second at the Tour of Flanders. As a result, Coates says the Domane has the widest downtube on the market and uses Trek's familar E2 headtube, as well as the firm's OCLV carbon fibre know-how.
While the adjustable rear IsoSpeed is a new take on an existing concept, the front IsoSpeed is completely new to the Domane SLR. "It's one of my favourite things we've ever developed," says Coates.
However, while the front IsoSpeed is a new development, it applies the same thinking as the original IsoSpeed. "By decoupling the steerer tube from the headtube, you can take advantage of the entire steerer tube flexing, rather than just above the headset," says Coates.
While the steerer tube is allowed to flex, resulting in a claimed ten per cent improvement in compliance over the original Domane, Trek have anchored it on both sides at the top, and they say this ensures there's no negative effect on the handling of the bike, or stiffness when sprinting. "It steers just like a normal Domane," says Coates. "We tested this time and time again as we're adding a technology that nobody's done before, and we wanted to absolutely nail it."
As well as testing prototypes of the new Domane on the cobbles of Flanders and Roubaix, Trek also built a 100m stretch of pave in their factory in Waterloo, Wisconsin, and ran repeatable tests on that.
Those tests showed Trek also had an opportunity to improve comfort through the handlebar, leading to the development of the IsoCore 'bar. It takes a number of features from Trek's existing IsoZone handlebar, including integrated padding, but now there's a proprietary, inter-laminar rubber pregnated into the carbon fibre, which, Trek say, helps dissipates road vibrations. The result is a claimed 20 per cent reduction in vibrations felt through the hands.
The difference between the front IsoSpeed and the IsoCore handlebar, Trek say, is the former deals with big hits dished up by the road, while the latter is focused more on high-frequency vibrations. Combined with the adjustable rear IsoSpeed, Coates says the Domane SLR offers "an incredibly balanced front and rear end feel."
Disc and rim brake options, additional tyre clearance
As you'd expect with an endurance bike - or, really, any road bike in 2016 - Trek have launched the Domane in rim and disc brake versions. The Domane SLR Disc adopts the flat mount caliper standard and uses 12mm thru-axles at the front and rear in a bid to improve stiffness and steering precision, while using a quick release-style lever to speed up wheel changes.
The Domane SLR Disc has stacks of clearance and is capable of taking 32mm tyres, while there's plenty of room in the regular Domane SLR, too, with clearance for 28mm rubber. Like the original Domane, both bikes also have hidden mudguard mounts - Trek say versatility is at its heart.
"The way people are riding bikes these days, they're riding wherever they want to go. When they go down the road and they see a dirt track on the left, they can take that dirt road and enjoy a little adventure, so we increased tyre clearance on the Domane substantially," says Coates, emphasising that the Domane offers that versatility while sticking with a road-focused geometry, unlike a gravel bike.
The Domane SLR will be offered in two geometries: Endurance and Pro Endurance. Trek describe the Endurance geometry as "stable but still racy, with a higher headtube for better control, handling, and responsiveness... perfectly tuned for most riders looking to put in the long miles."
The Pro Endurance geometry, on the other hand, is designed "to meet the demands of riders who prefer an aggressive out-front posture and require predictable handling over rough roads." What that translates to is a shorter headtube, while still retaining a longer wheelbase and lower bottom bracket, to keep that stable handling over cobbles and rough roads.
"It matches the fit of your Madone or Emonda," says Coates of the Pro Endurance geometry, "but it's a little more stable. You can get the exact same fit the professional guys are riding."
UK specs and pricing
Five versions of the bike will initially be available, three with rim brakes, two with disc brakes. The Domane SLR and Domane SLR Disc will both also be available as a frameset only. Here's the line-up:
- Trek Domane SLR 6 (Shimano Ultegra, claimed weight 7.46kg) - £3,600
- Trek Domane SLR 6 Disc (Shimano Ultegra, 8.3kg) - £4,000
- Trek Domane SLR 7 (Shimano Ultegra Di2, 7.49kg) - £4,400
- Trek Domane SLR 7 Disc (Shimano Ultegra Di2, 8.3kg) - £4,800
- Trek Domane SLR 9 eTap (SRAM Red eTap, 6.76kg) - £7,600
- Trek Domane SLR frameset - £2,400
- Trek Domane SLR Disc frameset - £2,550