Do road bikes need suspension?
More new road bikes are coming fitted with some form of suspension unit. Is this marketing gone mad or a vision of the future?
‘We enlisted the help of Mclaren to understand if making the ride smoother is actually faster and, using their simulation technology, we were able to prove that it is’
hy would I want suspension on a road bike?
It’s not such a new concept. Greg Lemond used a Rockshox suspension fork while racing on cobbles in 1991, before Gilbert Duclos-lassalle won Paris-roubaix using the system in 1992 and 1993. But, these days, some manufacturers see enough potential gains in comfort and speed that they’re introducing it to normal road riding.
‘When we first thought of suspension for road bikes, we wanted to give the rider a little more comfort, but we’ve also seen gains in speed too,’ says John Cordoba, road product manager at Specialized. As a result, the company’s Roubaix and Diverge bikes include Futureshock – a tiny suspension unit, sitting above the head tube, that allows the stem up to 20mm of vertical travel.
Trek also believes speed and comfort gains are to be had from suspension, going as far as installing its Isospeed decoupler system in its aerodynamic race machine, the Madone.
How does suspension make me faster?
By smoothing out the bumps. ‘We enlisted the help of Mclaren to understand if making the ride smoother is actually faster and, using their simulation technology, we were able to prove that it is,’ says Specialized’s Cordoba.
This is partly down to the fact that it reduces fatigue. ‘Suspension takes those road vibrations away from the hands, neck, forearms and triceps and, as a result, we’ve seen people be able to go longer,’ says Cordoba.
On perfectly smooth roads, this wouldn’t be an issue. But on the rutted and potholed roads we all know and love, the reduction of road buzz – provided by suspension – helps the rider conserve energy. ‘Suspension, on any platform, helps preserve momentum over obstacles, to keep your speed up,’ Cordoba adds.
There is also an element of traction added by the introduction of suspension – it can improve grip and handling on less-than-smooth terrain.
How is road suspension different?
‘On a mountain bike you obviously have much bigger obstacles – big drops, big rocks – but you’re still using the suspension for momentum and comfort,’ says Cordoba.
Brands such as Specialized, Pinarello and Trek have devised new, lighter weight units instead of retrofitting existing systems.
‘Pedalling efficiency and frame stiffness are more important on a road bike than on a mountain bike, while the terrain requires less suspension,’ explains Gerard Vroomen, co-founder of Cervélo and owner of Open Cycles. ‘This means you will need to find a system that sacrifices nothing (or very little) in pedalling efficiency and frame stiffness.’
What sort of system works best on road bikes?
Suspension can be at the front or back, in the form of springs, hydraulic cylinders or compressible polymers. Manufacturers are taking different approaches.
‘With “smoother is faster” in mind, we wanted to focus on the front end,’ says Cordoba. ‘Essentially, when the front wheel hits an obstacle, you want the bike to move over it without losing speed.’
Specialized has its Futureshock, Trek has its front Isospeed decoupler, which allows the steerer tube to move within the head tube, and Fox has produced air-sprung suspension forks specifically for road/gravel bikes (see p19). But some manufacturers have focussed on the back of the bike. Wilier has its Actiflex system, and Pinarello has the DSS 1.0 unit that sits between the K10S’S seat tube and seatstays.
‘Usually on rough terrain, pro riders shift their weight onto the rear wheel, unloading the front wheel,’ explains Massimo Poloniato, R&D engineer at Pinarello. ‘Considering that, we chose to work on the rear of the bike.’ Which is best? As Vroomen puts it: ‘The bottom line is that for MTB this has all been figured out already; for road it has not.’
Are there any disadvantages?
Keen-eyed tech nerds will notice some brands have trialled suspension systems with pros, only for riders to revert to conventional frames.
‘Suspension or no suspension is always a balance between the added weight of the system, the decrease in pedalling stiffness due to the system – meaning the flex in the links and pivots – and decreases in pedalling efficiency as it interacts with the suspension,’ Vroomen explains.
‘I think all riders want to make sure this new technology doesn’t take away from the other performance aspects that they want from a road bike,’ says Cordoba. For now, even though Specialized’s research suggests there are speed gains to be had on tarmac, the pros will likely use suspension only on rough terrain.
Will all road bikes have suspension one day?
‘I think that we’re going to start seeing more and more brands coming out with different kinds of suspension on road bikes,’ says Cordoba.
That said, Vroomen argues that there may be a simpler solution. ‘Get bigger tyres,’ he says. ‘That’s a form of suspension – it weighs little, the frame stiffness remains the same, and it has added benefits in grip and handling.’
The future is springy, but, as for the form it will take, we’ll have to wait… in suspense.