Ever more manufacturers are adding features to road bikes to deal with bumps and vibration. Here’s a look at the technology that’s out there to help you make the right buying decision.
Comfortable is fast: by reducing the fatiguing bumps and bangs that get through to your body, shock-absorbing bikes can keep you going faster for longer
Eschewing the sliding forks and suspension with pivots and shocks that add weight to mountain bikes, most shock-absorbing road bikes use clever frame design and materials to dissipate shock
Bikes like the Specialized Roubaix and Pinarello Dogma K10S use super-minimal mechanical shock absorbers that nevertheless keep them looking and riding like road bikes
Many shock-absorbing bikes use flexible seatposts to improve comfort, a trick you can also use on your own bike
We’re not talking about suspension when it comes to road bikes. At least, not suspension in the mountain bike sense with several inches of travel at both the front and rear. No, when it comes to road bikes we’re talking about design features that are intended to soften the ride just a touch.
Why would you want that? First of all, for comfort. Everyone wants to feel comfortable when they’re riding their bike, right? Life’s just better that way.
Second, you can have more control over your bike if you’re not being jolted around or bounced out of the saddle. As well as adding safety, that can lead to increased speed: “smoother is faster”, as Specialized is fond of reminding us.
Third, and kind of related, all those little bumps can gradually lead to fatigue over the course of a long ride, sapping your energy.
So what bump-taming features are out there?
Specialized has been in the vanguard of the bump-absorbing road bike trend for quite a few years now with the Roubaix series bikes. Endurance bikes to the core, Roubaix models feature a fork shock absorber Specialized calls Future Shock and the bump-taming S-Works Pavé seatpost.
Future Shock is essentially a spring inside the headset that allows the bars and stem to move up and down. There are interchangeable springs for riders of different weight. It can give up to 20mm of travel.
As of the 2020 model year there are two variants of the Future Shock. The more expensive Roubaix models get the new Future Shock 2.0, with on-the-fly adjustment and a hydraulic damper while the Comp and Sport get the Future Shock 1.5, with a lighter and more progressive spring than the first Future Shock and new bottom-out and top-out bumpers to improve the control.
When he took it for a spin over the cobbles of the Paris-Roubaix road race, Dave Arthur found "Over the ferocious pavé of the Arenberg and other key sectors that make up the classic route, the new Roubaix was deeply impressive. It was comfortable, shielded my body from the brutal impact forces, and above all was fast."
And it was the same story on Britain's weather-ravaged lanes. " The Future Shock works overtime to smooth out the wrinkles, cracks and holes that are abundant on my local roads, and which on a stiff race bike can lead to a bumpy ride," Dave wrote.
Under your bum all the new Roubaix bikes provide you with an S-Works Pavé carbon fibre seatpost, which Specialized says provides as much shock-absorbing movement as the old CGR post but is 80g lighter and looks like a regular seatpost.
The Dogma K10S features what Pinarello calls its eDSS 2.0 shock between the seatstays and the seat tube, with travel that relies on flex in the chainstays. It's an evolution of the previous K8S, with the addition of some clever electronics to control the suspension behaviour, and disc brakes to handle the all-important job of slowing you down.
The centimeter of available suspension travel, achieved via an elastomer spring and hydraulic damper, can be locked out for smooth road sections and activated when the going gets rough. The previous bike offered adjustment but not on the move. As well as simply locking and unlocking the suspension, you can also choose between a firm or softer setup to suit the road conditions.
We’d say that this type of suspension is really only suitable for something like cobbles (which is what Pinarello have in mind) or gravel roads. It would be overkill for decent Tarmac.
Trek has been including an IsoSpeed decoupler in its Domane endurance bikes for a few years. For 2020, Trek has turned it up to 11, with a more tuned version of Isospeed on the high-end SLR models, and whopping amounts of tyre clearance so you can go for even more cushioning and grip.
What the hell is an IsoSpeed decoupler? If you have a couple of minutes (a minute and 45 seconds, to be precise), this video from the time it was launched tells you everything you need to know.
In short, the seat tube isn't welded to the top tube/seat stay junction. The IsoSpeed itself consists of a bearing on either side, with a bushing forming the mechanical attachment between the top and seat tubes; this allows the whole length of the seat tube to flex under load, reducing the amount of road shock that gets transferred up to the rider.
When we reviewed the carbon fibre Trek Domane SLR 6, we said it was " incredibly smooth, filtering out the most severe vibrations on all sorts of rough roads, gravel tracks and cobblestones..”
The most affordable Domane with Isospeed in Trek’s 2020 lineup is the carbon-framed £2,100 Domane SL4. There are cheaper Domane models with aluminium frames, but they don't have the Isospeed decoupler and we think Trek is a bit cheeky to bill them as Domanes without it. At the other end of the scale there's the £9,650 Domane SLR 9 Disc eTap P1 with SRAM eTap electronic shifting and Project One custom paint.
Trek has transferred the IsoSpeed decoupler technology over to the Madone. You don’t get as much movement at the saddle as you do with a Domane but the difference from a standard road bike is appreciable.
We said, “If you're familiar with riding a full suspension mountain bike, it's nothing at all like that. Not in the same county. But the IsoSpeed system does smooth over the lumps and bumps to an appreciable degree. The effect is subtle, but it is noticeable.”
The problem is, the cheapest Trek Madone bike, the Madone SL 6, is priced at £3,900 (there are a few 2019 Madone SL6s around for less, but they have rim brakes). Look away if you're of a squeamish nature: the top model Madone SLR 9 Disc eTap will set you back £10,500.
Lapierre incorporates an elastomer into the top tube of its Pulsium endurance bike that’s designed to improve comfort with a set of features that Lapierre calls Shock Absorption Technology (SAT).
The elastomer comes in the form of a ring in the lower of the two joints between the top tube and the seat tube. Lapierre says that it acts as a shock absorber to dampen vibration from the road. The frame’s carbon-fibre layup is also designed to absorb shocks and vibration.
Lapierre says that the curved top tube flexes more easily than a straight one while the curved and narrow seatstays act like leaf springs for better impact and vibration absorption at the back end.
“It does actually smooth out the bumps on washboard surfaces and broken tarmac with very little in the way of spongy rebound when it's not wanted,” said our reviewer Stu Kerton. “The upper section of top tube works like a brace especially for the lateral forces from pedalling and cornering. A few times you put the hammer down and it feels a little soft but that's few and far between.”
Lapierre offers four versions of the Pulsium starting with the £1,799 RRP Pulsium SL 500 with a Shimano 105 groupset.
Bianchi has taken a totally different approach with its CounterVail Vibration Cancelling Composite Technology, or CV for short.
The CV is a viscoelastic material embedded within the carbon layup of certain areas of the frame. Bianchi claims it has 75% more vibration-cancelling capacity than other (traditional, if you like) carbon frames.
CV isn’t designed to deal with larger bumps – it is by no means a suspension system. Rather, it is intended to damp the high frequency vibrations that you get from a typical road surface, and the effect is subtle.
Bianchi says that the key benefits to using CV are reduced muscle fatigue and increased energy savings, improved handling and rider control, and increased rigidity and peak power output over long distances.
Bianchi first introduced CV on its Infinito CV endurance bike, and has since used it on the Specialissima lightweight race bike.
The claims might sound like PR hocus pocus but when we reviewed the Bianchi Infinito CV we said, “You still get plenty of feedback from the road surface through the controls, but the CV simply removes the harshness, damping the vibrations and delivering a smoother ride.
“The benefit of the CV technology is that it's always working. Even out of the saddle on the climbs, the frame is muting vibrations. An area where the CV really shines is on fast and steep descents with an unpredictable road surface.”
We were so impressed that we made the Bianchi Infinito CV our road.cc Bike of the Year in 2013-14.
Loads of bike manufacturers say they make their seatstays flexible so as to provide plenty of comfort. That’s often just a case of making them skinny and thin walled, although some brands go further.
Volagi, for example, used what it called Longbow Flex Stays “to isolate the rider from harsh road vibrations and impacts and provide up to 6mm of movement at the saddle”.
We reviewed the Volagi Liscio frameset here on road.cc and said, “The Long Bow flexes just enough to take the sting out but not to the extent you feel any loss in the performance stakes.”
Sadly, Volagi suspended operations after co-founder Robert Choi was hit by a driver and subsequently fell into a coma.
Merida uses Flex Stays on many of its bikes, where “the profile of the seat and chainstays and the lay-up schedule of the carbon [are adapted] so the rear end works like a flat spring, absorbing surface bumps and reducing vibrations”.
Many other brands do something similar although Merida is unusual (but not unique) in that it also incorporates organic flax fibre between the individual carbon layers, the idea being to filter high frequency vibrations. It’s used in the lightweight Scultura.
Cannondale uses what it calls SAVE Plus Micro-Suspension on its carbon fibre Synapse endurance bikes. It stands for Synapse Active Vibration Elimination. There are several aspects to SAVE Plus, one of the claims being that the seatstays bend and compress under load like a spring.
Cannondale also says, “The Synapse's carbon layup was designed to maximise something called ‘inter-laminar shear dissipation’. Basically this means that the fibers are oriented in such a way that vibrations get caught up in the layers and are diffused before they can make it to rider. This helps tune out that energy-sapping road buzz and keeps you fresher.”
A slim seatpost provides more movement at the saddle. Cannondale goes super-skinny at 25.4mm, but don’t underestimate the difference a 27.2mm seatpost can make over a 30.8mm, for example.
When we reviewed the Cannondale Synapse Carbon Ultegra Disc we said, “It's smooth enough for the harshest roads and comfortable for the longest rides, yet never holds you back when you want to get a shift on.”
In this article we’ve concentrated on frame features that are designed to deal with bumps and vibration, but there are many other ways to make your existing bike more comfortable; you can fit wider tyres, switch your saddle, change your bar tape, and so on.
For more ideas on adding comfort go to our article: 9 ways to make your bike more comfortable.
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Mat has been in cycling media since 1996, on titles including BikeRadar, Total Bike, Total Mountain Bike, What Mountain Bike and Mountain Biking UK, and he has been editor of 220 Triathlon and Cycling Plus. Mat has been road.cc technical editor for over a decade, testing bikes, fettling the latest kit, and trying out the most up-to-the-minute clothing. We send him off around the world to get all the news from launches and shows too. He has won his category in Ironman UK 70.3 and finished on the podium in both marathons he has run. Mat is a Cambridge graduate who did a post-grad in magazine journalism, and he is a winner of the Cycling Media Award for Specialist Online Writer. Now pushing 50, he's riding road and gravel bikes most days for fun and fitness rather than training for competitions.