Tour de France tech: Creeping saddles and shortening crankarms
The quest to minimize aerodynamic drag has driven the majority of equipment changes in pro racing, from airplane-like frames and wheels, to bullet-like helmets and skin-tight clothing. We’ve already seen the move to narrower handlebars in recent years for the same reason, and now we’re seeing two more positioning trends designed to help riders move more efficiently through the air: shorter crankarms, and saddles with less rearward offset.
Aero equipment unquestionably lets today’s racers move faster than non-aero gear. At typical racing speeds — and even on shallower climbs — the vast majority of a rider’s energy is spent overcoming air resistance, and so it’s completely logical to want to reduce the weight of that anchor as much as possible. But while all of that fancy equipment certainly helps, it’s still the rider who comprises the biggest line item in the equation, and so it’s even more logical that the most attention should be paid there.
But whereas designers have plenty of liberties when shaping down tubes, rims, and helmets, altering the human body isn’t so simple. Riders can’t do much to change the way they’re shaped, after all, and changes in position made in the aim of aerodynamic efficiency still have to be balanced with physiological efficiency.
One of the biggest limitations in that sense is a rider’s hip angle, or the angles the upper leg makes with the lower torso when the pedal is at the 12-o’clock and 6-o’clock positions, and it’s critical to maintain a fairly narrow window in both of those extremes for proper pedaling mechanics. Lowering a rider’s handlebar might reduce frontal area and drag, for example, but if doing so brings the legs too close to the torso, the rider can’t pedal or breathe properly, thus negating any aerodynamic gains with losses in power.
Saddle setbacks have long held their customary positions for a variety of reasons, including (but not limited to) postural balance, muscle group activation, and just plain tradition. But as strong a motivation as tradition may be, that still pales in comparison to the prospect of going faster.
Two men’s teams that have embraced this philosophy are Quick-Step Floors and Trek-Segafredo, both of whom are running less saddle setback relative to several years prior. The change is more visually dramatic with Quick-Step, with at least half of the road bikes of this year’s Tour squad sporting a zero-offset seatpost and saddles that are positioned relatively far forward on the rails — quite the departure from the huge offsets once considered to be “pro.”
Some riders, such as Trek-Segafredo’s Jasper Stuyven, have also switched to shorter cranks, too.
According to Trek Precision Fit program manager Matt Gehling, shortening the crankarms and moving the saddle forward means the rider’s legs aren’t coming up as high at the top of the pedal stroke, which then allows riders to drop down lower up front for better aerodynamics, all of which can be done without losing power.
“The big reason the team wanted to try it, and this was at first focused on time trial bikes, was to get their front ends lower,” he said. “A time trial position is the worst thing you can do on a bike for your hip angle, and that is why triathlon bikes come with steeper seat tube angles and shorter cranks; both of these things open the hip up more.
“Trek-Segafredo riders are limited by UCI rules so we can’t slam the seat forward, but shorter cranks are a decent option to try if we’re trying to get the athlete more aggressive.”
That said, old habits still die hard, even if there are real performance gains to be made, and especially when you’re talking about professional riders who have spent tens of thousands of kilometers in a position they already know well. The Quick-Step and Trek-Segafredo riders seem to be adapting to the more forward positions without too much objection, but there’s clearly a bigger hurdle with the shorter crank lengths.
“Adaptation is a real thing,” Gehling said. “You need to spin faster to maintain the same wattage since you’re spending less time in the pushing phase with shorter cranks. Some riders are able to adapt; some aren’t. [Trek-Segafredo technical director Matt] Shriver has found some interesting feedback from some riders that at certain wattages (around 350W), the cranks feel fine, but they don’t feel as good at the big efforts (400W+). This is likely because it is harder to maintain a high cadence at those higher efforts.
“When they are really suffering and want that extra leverage at the lower RPMs, they prefer the longer crank arms,” Shriver added. “So we have been back and forth. Some riders have stayed on the shorter arms, but most have crept back to longer cranks. Jasper Stuyven [who stands at 1.86m / 6ft 1in in height] has switched from 172.5mm to 170mm on his road bikes. He is having his best season yet. I believe it’s because he committed early on and adapted to the change.”
It perhaps goes without saying that this sort of thing is nothing new to triathletes, who adopted those more forward positions ages ago. And Lotto-Soudal rider Adam Hansen has used this sort of position (and unusually narrow handlebars) at least as early as 2013.
Is this the start of a bigger trend? It’s too early to say, but given how things often go in the pro peloton, my guess is that we’ll soon see more riders moving in this direction. If history is any indication, all it takes for widespread change in those circles is for a handful of key influencers to make the move, and then the rest will follow.