Cycling Science in the Tour of Flanders – Cobbles & Breakaways
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I hope your Sunday is free, one of the most eagerly-anticipated races in professional cycling, the second of the five monuments and the biggest Flemish race of the year – the Tour of Flanders is upon us (Sunday 6th April). And if that wasn’t enough its followed next weekend with Paris-Roubaix, or the ‘Hell of the North’, cycling’s hardest one day race – both featuring adamant amounts of ‘Grit, determination and a stoic acceptance of physical pain’.No region is as closely associated with professional cycling as Flanders, and to make a FA Cup final comparison (for the cycling beginners out there) this is it. It is truly one of cycling’s great spectacles with the locals flock to the roadside every year to see the world’s best classics riders.
If you ever wanted to see a summary of David Millar’s, a five-time TdF stage winner, quote – “What makes one cyclist better than the other is simply the ability to suffer more” – this two weekends are it.
And one huge factor on all these statements is one race factor – the cobbles. Punishing, long stretches of stone that cause pain, suffering, punctures, broken wheels, cursing, cracked frames, mangled collarbones and more suffering. If the Sufferfest videos – enemy/training partner of any indoor enthusiast – was in a metaphorical form, it would be the deprived abuse of riders thigh as they climb the cobbled slopes of the Belgian bergs.
[If you have been living under a rock & need to catch up on the European race season up to this point, check out the ‘Race-Fest’ article put on pezcyclingnews.com].
The favourites for the race will be Fabian Cancellara (Trek) and Peter Sagan (Cannondale) and Tom Boonen (Omega Pharma-QuickStep) [who is seeking a record breaking fourth win, and these days focuses his season almost exclusively around this race & next weekend’s Paris-Roubaix]. Victory for Cancellara would draw him level with Boonen on three wins, while the much talked about Peter Sagan is desperate to claim his first ever monument. For those fans of Team Sky, their preparations for the races has been dealt a blow with the withdraw of Ian Stannard – who had looked so impressive in winning Het Nieuwsblad a month ago, and now is replaced by the Paris-Roubaix focused Bradley Wiggins – but teammate Geraint Thomas is it great form with his third place in the E3 Harelbeke at the end of March.
Although the final, traditional pairing of the Muur & Bosberg climbs have been replaced by further laps of the Oude Kwaremont & the Paterberg (critics citing corporate reasons because they are hospitality friendly) I have no doubt we will see a very tactical & aggressive race……tragically we won’t see this escape from Cancellara (skip to 2:39 to see how climbing in the saddle & breaking away is done)…..
I wanted to look briefly today at some of the gear & science behind professional racing on the Tour of Flanders & Paris-Roubaix; no doubt this weekend you will be bombarded with snapshots of the latest bikes being rolled out across the Belgian countryside.
As you will see from this Bicycling.com 2013 article on ‘Bike Tech on Display at the Classics‘, the cobbled races are unique in drawing out technology that matches comfort with speed. Many of the classic machines have a more aggressively sloped top tube, taller head tube & longer wheelbase, to provide a more stable geometry & better tire clearance from the grit & muck. Peter Sagan’s Cannondale Synapse H-Mod has a 3cm taller head tube than his Evo, as well as a shorter top tube. It combines the top tube of a 58cm frame with the head tube and seat tube of a 54cm. This allows him to get stretched out, and the handlebars low. It’s the same position as he has on his SuperSix Evo.
As we known from our TT bikes, high frame stiffness is one of the most important parameters for a racing bike, with huge gains in steering stability & less demand for pedalling power due to little frame deflection. However for the ‘cobbled classics’ of the Tour of Flanders and Paris-Roubaix, success is determined by the ability to ride on the ‘stones’ efficiently to save energy & skillfully avoid crashing. Furthermore, on top of some mild discomfort the Tour of Flanders also has the fabled hills – Koppenberg, Patersberg and Oude Kwaremont – being particularly memorable for their steepness (20+ percent grade) and difficulty. With the sport & its investment becoming even more intensive in the last few years – with riders put into sprinter, climber & domestiques catergories – Belkin Pro Cycling Team has gone so far as to recruit a former Cyclo-cross world champion, Lars Boom, into their Classics roster.
Of course to be a winner in these races, riders have to learn this proficiency. Stuart O’Grady, who won Paris-Roubaix in 2007, agrees. “I remember when I started out and tried to follow [Andrei] Tchmil and [Peter] Van Petegem in Flanders. My objective for the whole day was just to follow those guys. Be their shadow. It was impossible. I couldn’t believe it. One minute I am there behind them and the next minute I am in 80th and they are sitting in the first five. I was asking myself ‘how the hell do they do that?'”
If we are to compare elite bikes on the cobbles – specifically for comfort – the lab studies data from two specific tests – 1. Torsional stiffness test: which stimulates pedaling load & measures the bike’s stiffness at the bottom bracket, head tube & seatpost; 2. Using accelerometers measure how much vibration is transmitted up through the bike from bumps on the road.
Pro teams are obsessed with configuring state of the art bike technology to improve rider performance in this April baptism of fire. You may recall last year that Bianchi introduced on its Infinito CV, with U.S.-based Materials Sciences Corporation, the “Countervail Vibration Cancelling technology,” which includes a visco-elastic material included in the lay-up of the frame and fork. Europcar even used the Colnago Prestige Cyclo-Cross bikes
In 2014’s edition of the race this innovation and passion for technology continues (I suppose if you are going to inflict this meet on your riders race calendar you have to show you care….). If we look at maintaining lateral & torsional stiffness (while maximizing vertical compliance) BMC has introduced the ‘Tuned Compliance Concept’ which internal testing claims gives a 20% stiffer bottom bracket than their flagship bike the SLR01.
It seems that suspension & comfort (Merckx must be thinking man-up) is prominent in the note pads of cycling R&D teams, with several of the Pro Team releasing classic perspective bikes. The Lapierre Pulsium saw its first race at the Grand Prix E3 and the teams joins only a few other companies on the roster offering a bike with borderline rear suspension using an elastomer ring to soak up the bumps. A Power Box design, allows the bottom of the bike to be super stiff for power transfer, while the upper section of the bike is designed to be as flexible as possible.
The Trek Racing Team has released the Classic edition of the Trek Domane – a bike which introduced the IsoSpeed decoupler ; a new technology to bring suspension to the performance road bike by separating the rider from the bumps at the seat tube/top tube junction. This progression in bike innovation was demonstrated in the literature back in 2013 by among others a group of Gent University material science researchers (as you would expect Belgian scientists have been at the forefront of experimental mechanics into ‘cobble science’). Following on from their paper on ‘Instrumentation of a racing bicycle for outdoor field testing & evaluation of the cyclist’s comfort perception‘ Vanwalleghem et al naturally investigated in 2013 new approaches in evaluating vibrational comfort when riding on a ‘rough surface’ . In this study, outdoor tests on cobblestones roads concluded that cyclist’s comfort was not only quantified in terms of acceleration but also in terms of force & velocity at the bicycle-cyclist contact points.
In parallel with bike attributes, tyre pressure can make a huge difference in optimum performance on race day. Team Giant-Shimano recently went out with their new Giant Defy Advanced SL bikes to test their new Vittoria tyres on the cobbled streets. As you will see more & more with race team set ups today, team coaches – in this case Tom Davids (Technical R&D Expert), Adriaan Helmantel (Trainer) & Marc Reef (Coach) – go out with equipment specialists so the riders can give instant feedback on the bike set-up. For example, the new Giant bikes were matched up with either 25mm or 27mm Vittoria tyres at different pressures.
This is a great behind the scenes look at Tom Boonen’s Paris Roubaix bike from the 2013 edition – note the Rolf’s reference to tire pressure & even the ‘little’ things like double handlebar tape.
Frankly, is it all about the breakaway?
As we have seen from the Cancellara video at the beginning, the terrain of the Tour of Flanders allows the strong riders to make a clean breakaway from the chasing pack. Interestingly this race plays havoc on the traditional ‘science’ of the breakaway. Tim Olds 1998 paper on ‘‘The mathematics of breaking away and chasing in cycling‘ [you find loads of random articles when you put your mind to it] found that the critical factors affecting the likelihood of success include; the distance remaining in the race, the speed of the breakaway group, the number of riders in the chasing & breakaway groups, how closely riders in each group draft one another; the grade; surface roughness, as well as head- and cross-winds. When you consider these elements in the punishing, crash-prone competition in Belgium this weekend, compared with say the Tour de France – where breakaways are very unlikely to succeed – you can see why the Tour of Flanders (and its twisting, technical route) is a highlight of the racing calendar.
Of course with all of this talk on innovation & breaking away you may ask ‘why not just ride on the road side & away from the cobbles?’.
Which Stuart O’Grady’s answers: “The best way is to ride straight down the middle of the road. It is the hardest, but it is the best. When riders start getting a bit tired or a bit desperate they dive off into the sides or into the dirt because it is a little bit easier ride, but that is where the rocks get flicked into and all the punctures are going to happen. The guys riding down the center of the road generally are the guys who are going pretty strongly.”
And finally if all of that was just a bit too much information at one time, GCN provides a fantastic overview on how the pro teams prepare their bikes for Paris-Roubaix:
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