One thing that has stood out in both the Tour de France and the US Pro Challenge this year is the extreme descending position adopted by many riders on steep descents. Instead of using the traditional method of sitting on the saddle with the hands next to the stem and pedals horizontal, daring riders have taken to sitting on the top tube.
Although several pros have tried this in the past few years, I suspect that because Tinkoff-Saxo’s Peter Sagan got lots of camera time in the Tour while squatting on the top tube, the technique has gone mainstream.
I can’t figure out why.
First, it’s dangerous. Bikes are designed for the rider’s weight to be on the saddle, not a foot forward on the top tube. Seeing BMC’s Rohan Dennis wobble down the Moonstone Road descent in the time trial stage of the US Pro Challenge highlighted how shifting weight in this way could lead to a potentially deadly shimmy.
And it’s hard to get back into the saddle without snagging shorts on the saddle nose. The results could be not only painful but embarrassing.
Also, I’m not at all sure that the new position, dubbed the “super tuck,” is more aero than the traditional posture. While they are sitting on the top tube, riders’ backs are slanted upward which looks to me like it negates any advantage from the lower profile.
And squashing the upper body in the cramped area between the seat post and the stem results in a hunched back — bad for smooth airflow. I suspect that quite a few teams will hit the wind tunnel this winter to determine if there’s really an aero advantage to the super tuck.
Finally, some pros even pedal while straddling the top tube. It makes my knees (not to mention my, um, pelvic region) ache to watch. Why pedal in such an awkward posture? If you’re going slow enough to pedal, it’s better to get the most out of each pedal stroke.
Teams spend hours and big bucks to get saddle height perfect for maximum power output. I can only imagine how many fewer watts a rider puts out with such an extreme bend in his knees. Far better to take a chance on losing 10 or 20 watts to the aero disadvantage of the traditional position (ifthere is one) compared to gaining those aero watts in the super tuck but losing 75 watts due to inefficient pedaling.
Of course, pros will grab any perceived advantage to go faster. And their outstanding bike handling skills will often enable them to get away with the super tuck. Not so with recreational riders who are generally less skilled bike handlers and in some cases have quite a bit more bodyweight to cram in the limited space of the top tube.
The usual advice pertains here — don’t try this on your home roads. The extra second or two you might gain per mile of steep descending isn’t worth it unless a big paycheck is on the line.
It’s almost certainly not worth it for even the most skilled pro. One gruesome crash by a top rider on TV in a big race and we will probably have seen the end of the super tuck.
Coach Fred Matheny is an RBR co-founder who has four decades of road cycling and coaching experience. He has written 14 eBooks and eArticles on cycling training, available in RBR’s eBookstore at Coach Fred Matheny, including the classic Complete Book of Road Bike Training, which includes 4 eBooks comprising 250 pages of timeless, detailed advice and training plans. The Complete Book is one of the many perks of an RBR Premium Membership. Click to read Fred’s full bio.