Garmin-Cervelo's Tom Danielson Retul'd 

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After a disappointing time trial in the Tour de Romandie, Garmin-Cervelo cyclist Tom Danielson stopped by Retul Studios in Boulder, Colorado to have his position assessed before the Amgen Tour of California.

Danielson brought both his road and TT bikes so his biomechanical and fit coordinate data could be recorded.  The first step was to measure both bikes using the Zin, Retul’s 3D digitizing tool used to record bike setup. Because professional cyclists switch equipment so often, it is important to have an accurate history of positions and critical bike measurements to eliminate the chance for bike setup error by the rider and team mechanics over the course of the season.

Coming into the fit, Danielson’s biggest concern was that his TT position did not feel right. Upon measuring his road and TT bikes, we discovered their saddle heights were exactly the same.  This is not ideal because most cyclists come to the nose of the saddle when time trialing (as does Danielson), but remain rearward on the saddle in their road positions.  This is an issue because sliding to the nose of the saddle and rotating the pelvis to the anterior artificially creates a lower saddle.

An important note is that Danielson’s knee angle was the same on both road and TT bikes. Danielson was preserving his knee angle (from the road position) by dropping the heel (dorsi flexion) to try and get more knee extension in his TT position.  When rotated forward on the TT bike, a rider's range of max power production during the pedal stroke is also rotated forward.  Athletes often do not take this into consideration (forward rotation) and that same ankle angle will appear to be more open or toe down, when the angle is actually very similar or the same.  So, when the rider attempts to mimic the “heel down” orientation, he or she actually over compensates and misses out on the full range of max power production.

After reviewing the evidence with Danielson, his saddle was raised 5 mm, which allowed him to open up at the ankle (plantar flexion) and rotate his pelvis, giving better power distribution during his pedal stroke while time trialing.

On the front end of the bike, Danielson was too stretched out and uncomfortable trying to support himself in the aero bars. Typically the further away the rider gets from core, the weaker he or she becomes. A more compact, supported position would improve comfort for Danielson, and allow better posture to optimally produce power. Danielson’s aeropads were moved back 5 cm, and the stem was changed to a 90 mm -6 degree 3T stem (from a 100 mm -17 degree stem). Moving to an 80 mm -17 degree stem would be ideal, but this change can come later as Danielson fully adapts to supporting himself in the new position. After these changes were made, Danielson was able to lay across the front end of the bike in a very relaxed manner, using his skeletal system to support himself rather than his erectors (major back muscles).  His back angle increased by 2 degrees yet allowed him to relax and drop his head and reduce his frontal surface area. 

Another benefit occurred in Danielson’s hip angle at the top of the pedal stroke (“hip angle closed” on the Retul data sheet).  Danielson’s hip angle was opened by 3 degrees through the combination of the saddle and front end changes.  More “open” isn’t always better or riders climbing up steep gradients (where aerodynamics are not a factor) would be sitting straight up on their bikes. Instead, the riders decrease their hip angles by bending their arms and lowering their back angles in order to generate power to get up the climb.  When it comes to time trialing, a too open (obtuse) hip angle is not the problem and often times this angle needs to be opened to allow the rider better movement over the top of the pedal stroke. There is an optimal hip angle range that a rider will want to perform within.  In Danielson’s case, his hip angle, although ridable, was too acute for him and the changes were very beneficial.            

Without a high level of measurement accuracy and removal of human error, the necessary changes could not have been discovered. The adjustments made to Danielson’s saddle position Cervelo were under 5mm, and the resulting changes in his body angles were below 3 degrees. Although these numbers may sound subtle, the effects have been significant for Danielson.  See Danielson's post-Tour of California interview on NBC Sports.