As any cyclist knows, setting up the bike correctly is vital for efficient and pain-free riding. Among the things to consider are saddle height, angle and fore/aft position and stem/handlebar height and stem length.
This of course assumes that the size geometry of your frame is reasonably matched to your body dimensions in the first place. Of all these aspects, saddle height is probably regarded as the simplest and least troublesome adjustment to make – just loosen the Allen bolt, adjust and retighten.
And maybe that’s a good thing because new research by Spanish scientists suggests that getting your saddle height absolutely spot-on is even more important for efficient cycling than was previously believed.
Researchers set out to investigate the effects of small changes in saddle height on the movement of the limbs during the pedalling action and the gross efficiency of cycling. Gross efficiency or ‘GE’ basically refers to how much energy in terms of forward movement is created per calorie of energy expended by the cyclist when pedalling.
The higher the gross efficiency, the more effectively a cyclist can convert his or her expended energy into forward motion – an important part of determining endurance performance.
In the study, 14 well-trained cyclists performed a sub-maximal pedalling test where they rode at 70-75 per cent of their maximum oxygen uptake capacity (moderately hard), while sustaining a pedalling cadence of 90rpm.
Each cyclist performed three separate six-minute blocks where they rode at their preferred saddle height, two per cent higher than preferred and two per cent lower than preferred. These six-minute blocks were also performed in random order so that the GE measurements in each saddle position wouldn’t be skewed by increasing levels of fatigue.
In addition to measuring the GE of each cyclist in each saddle position, the researchers also measured the movement at the hip, knee and ankle joints to see how saddle height affected the actual pedalling motion.
In a nutshell
The first finding was that GE was significantly lower when the saddle height was raised two per cent above preferred (GE dropped from 20.4 per cent to 19.9 per cent). Also, the cyclists required more oxygen to sustain the sub-maximal pace in the two per cent above preferred height position – oxygen consumption rose from 42.8ml per kg per minute to 43.8ml per kg per minute.
Dropping the saddle height below the preferred position also reduced GE, though the reduction was smaller.
Overall, a drop of 0.8 per cent in GE was observed when comparing the saddle heights where the best and worst GE was obtained.
When looking at movement of the joints, the scientists discovered that either raising or lowering the saddle height away from optimum increased the range of movement in the hip, knee and ankle joints by an average of one, three and four degrees of movement respectively.
These results suggest that having the saddle height out by as little as just 1-1.5cm can make a very big difference in your cycling efficiency.
And although interim heights between optimum and +/-2 per cent weren’t tested, there’s every reason to believe that smaller height differences of as little as 0.5cm could still make a significant difference. The reason for this seems to be that when the saddle height is not optimised, unnecessary and inefficient movement is created at the hip, knee and ankle joints.
The study suggests that setting the saddle height too high is worse that setting it too low. If you have access to a heart rate monitor and an accurate power meter you’ll find that your optimum saddle height will be the one that produces the lowest heart rate for a given sustained power output!
This article was first published in the August 22 issue of Cycling Weekly. Read Cycling Weekly magazine on the day of release where ever you are in the world International digital edition, UK digital edition. And if you like us, rate us!