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Road bike suspension

Suspension systems promise a softer ride, but are they an innovation too far for road bikes?

Cyclist comfort
Stu Bowers
30 Dec 2015

Traditionalists will spit cake crumbs across the cafe at the mention of suspension on road bikes. They’re only just recovering from choking on their tea over wide tyres and disc brakes, and the idea of added suspension seems like another step closer to turning road bikes into mountain bikes.  

The only way the sceptics will be won over is if bike manufacturers can convince us that their innovations will provide real improvements in performance for us all. Pinarello’s new K8-S, with a suspension unit at the top of the seatstays, has become the ride of choice for Team Sky at the cobbled Classics, but most of us aren’t racing over the jagged roads of Roubaix. Shock absorbers are less necessary for the average Sunday club run, so will suspension bikes remain confined to the niche of pros racing over cobblestones, or is this technology that we can all benefit from? 

Shock revelations

Pinarello’s K8-S might be big news now, but it’s certainly not the first to bring suspension to road racing. Gilbert Duclos-Lasalle won Paris-Roubaix in 1992 with Rockshox suspension forks fitted to his Z-Team Peugeot bike. Bianchi took things a step further and produced a full-suspension machine for Johan Museeuw’s 1994 Roubaix bid but it broke during the race, robbing him of a potential victory. That was the demise of the project and was perhaps responsible for the subsequent lull in mainstream manufacturers pursuing any similar designs. Fast forward a decade and George Hincapie lined up for the 2005 Paris-Roubaix aboard a carbon Trek Madone with what Trek called SPA (Suspension Performance Advantage), an elastomer-based shock absorber positioned at the top of the seatstays, providing 13mm of rear suspension travel. Hincapie placed second – his best ever Roubaix result – but again the bike never made it to market. 

Johan Museeuw Paris-Roubaix 1994 Bianchi suspension road bike

Over the past ten years attention has moved away from shock-based suspension systems, although the goal of marrying comfort to speed has remained. Manufacturers such as Specialized, with its Roubaix, and Trek, with
its Domané, have been working with the properties of carbon fibre by honing lay-ups and tube shapes to significantly improve compliance, such that an actual shock absorber was deemed unnecessary. 

Moots, a custom titanium framebuilder based in Steamboat Springs, Colorado, was an early pioneer of integrating a shock absorber into the rear stays of a road bike, something it was producing as far back as the early 1990s - see Moots history

‘The market was not ready for a rear suspension road bike at that time,’ says Moots’ Jon Cariveau. ‘We developed the idea off the back of the success of our soft-tail mountain bike, which used the same in-built elastomer shock. We utilised the flex in the titanium chainstays rather than a pivot so the design was very simple, with few moving parts so it added very little weight, was reliable and needed very little maintenance. We’re only a small company so knew it would take a bigger name with the marketing budget to really get the public to accept it and for suspension road frames to take off.’ 

Johan Museeuw Paris-Roubaix 1994 Bianchi suspension road bike

Craig Calfee, technical director at Calfee Designs, another bespoke US framebuilder with a firm belief in the benefits of integrating suspension in road bikes, agrees: ‘We’ve been ready to go with a rear suspension road frame for over five years already and we’re working on a front suspension system too, but we’ve been kind of waiting for someone with more mainstream presence to give it the green light. Trek launching the Domané in 2012 was a sign that perhaps the market was ready to accept more radical changes to road bike design.’ 

Cariveau adds, ‘The consumer landscape is getting younger and more accepting of change. It’s not so much about the old dyed-in-the-wool roadies. This new wave is more engaged with new technology. Cyclists are accepting now
that they can ride longer and more efficiently if they are comfortable, and they are more willing to experiment with stuff.’

What goes around…

Another key development is the recent UCI rule changes that now forbid brands from producing ‘one-off’ bikes for pro riders, so when Pinarello developed its K8-S for Team Sky, assisted by Jaguar Land Rover’s engineers, it was well aware it would have to make the bike commercially available. Projects can no longer disappear without trace as so many have in the past. Bradley Wiggins apparently described the K8-S as a ‘game changer’ after he rode it to 18th place in the 2015 Paris-Roubaix, and Pinarello has brought the concept into the mainstream. The company insists that the K8-S is not just for pros on cobbles. 

Cyclist comfortable

‘You can adjust a bike’s comfort up to a point – bigger tyres, different saddle, thicker bar tape – but there is a limit,’ says Fausto Pinarello, the company’s owner. ‘We knew there was so much more scope to increase comfort by manipulating the frame. Yes, first and foremost, we tried to make the best bike for Team Sky, but now I’d say 99% of cyclists would be comfortable riding this bike. We developed the suspension unit to be as light as possible. It weighs less than 100 grams [the K8-S complete frame weight is a claimed 990g], it’s adjustable and easy to maintain. The seatstays have been heavily reshaped, flatter vertically and wider to take the flex allowed by the suspension, but still offer the same levels of lateral rigidity as the Dogma F8. This makes the bike really versatile. Sky riders can ride it in the Classics as well as Grand Tours if they want. OK, maybe not for elite level sprinters, but for everyone else there is no sacrifice in performance, it is a true evolution.’

Calfee echoes Pinarello’s sentiment, saying, ‘In our tests [to prove the suspension was more benefit than detriment] we’ve found a small margin of performance gain. It was only about 2% faster, but we know small gains count for a lot and just a few percent could be hugely significant. Handling is much improved, particularly at high speed, and we even found it climbed better. But we know the public will be nervous to accept trends like suspension. Basically people will want to know that there is no loss of performance, but our tests actually show the complete opposite. You will not be giving up anything. We can achieve the same level of lateral frame stiffness and with the shock unit only adding about 20g extra weight.’ 

Calfee is so confident in suspension in the road market, he boldly predicts that in less than five years all the pros will be on it. ‘Even the sprinters,’ he says. ‘The rear shock helps to keep the back of the bike more planted in sprints, stopping it from bucking around.’

Pinarello Dogma K8-S suspension

Cariveau is a touch more cautious, saying, ‘Whether actual rear suspension designs come to fruition or not, this is definitely a mark for the industry. A softer ride to reduce vibration and fatigue is becoming the norm. People want a good experience and if it’s too harsh it’s not fun.’

One thing we can be sure of is that it won’t be long before more manufacturers want a piece of the action. We expect next season’s spring Classics to be a launch pad for a glut of new designs in the wake of the K8-S. There seems
to be growing evidence that the benefits of having suspension extends to everyone, not just the pros. We’ll have to see what emerges in the next few months, but keep an eye out for the full review of the Pinarello K8-S.

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