By Coach Rick Schultz
First off, getting a great bike fit is absolutely essential before we can start talking about correct pedaling style, pedaling efficiency and power. The reason is that it will put you in the right position for maximum power while minimizing a chance for injury.
I believe it’s important to get a bike fit from someone who looks at bike fitting from a kinesiology point of view. I work with several physical therapists and can relate our process.
Cleat placement is where I like to start. Correct cleat placement addresses toe-in/heel-in issues, Valgus/Varus foot angles, knee alignment (knees going straight up and down) and maximizing pedaling efficiency via knee placement directly over each pedal spindle.
Saddle placement is next. This is also important since it helps to maximize power while minimizing the stresses on your knees. You want the correct height so that you are not over-flexing or over-extending your knees. You will want the correct fore/aft placement so that, again, your knees are lined up straight and directly over the pedal spindles when you’re pressing down hard on the pedals.
Since your feet are locked into the pedals, they don’t move much. Neither do your hips. So the only part of the legs that are left free to take up any “slack” are the knees. When your knees go out at the top, you are applying a compression force on the inside of the knees (not a good thing). At the same time, you are also applying a distraction (separation) force on the outside of the knee (also not a good thing). In other words, correct vertical alignment of the knees is absolutely essential for continued knee health.
Saddle tilt is also important. If the saddle is pointed down too much (nose down), you end up sliding off the front. If it’s tilted up too much, you end up putting too much pressure on the soft tissue, causing other issues such as pain, possible erectile dysfunction, crushing of pudendal artery and/or nerves, etc. Saddle shape and saddle size is also important, i.e., you don’t want a saddle that is too narrow or too wide for you, either.
Cockpit placement is the third area to address. You want the right extension via the stem. Beware of fitters who determine that your bars are too far away from you and try to compensate by moving your saddle forward. Saddle placement is all about knee alignment and knee angle and NOT to compensate for a stem that is too long or too short or a frame that is too large or too small.
K.O.P.S. for road bikes. I know there are fitters who don’t like Knee-Over-Pedal-Spindle, but I do, and here’s why. It places your knees directly over the pedal spindles so that you are pushing tangentially at that point of the circle. This is the point at which you are applying the most force to the pedals. You want your knees to be pushing straight down at this point, not pushing forward or pushing backward.
The most efficient pedaling style is pedaling in a circle, just like a motor that applies the same force tangent to every point along the circumference of the circle. You want to do the same, or at least strive to do the same. So, for each leg, you want to push down along the entire front part of the pedal stroke (roughly 12 o’clock to 6 o’clock), then pull back and up along the entire rear part of the pedal stroke (roughly from 6 o’clock to 12 o’clock). You want your knees tracking straight up and down, not moving in or out at the top.
Foot position. Assuming that you have had a bike fit from a fitter who knows what they are doing, the correct saddle height should leave you pedaling a little flatter footed than “tippy” toe-down. The reason is that a majority of cyclists’ saddles that I have done bike fits for are too HIGH. Being too high in the saddle forces you to “reach” for the pedals, i.e., tippy toe-down. Cycling on a bike where the saddle’s height is perfect for you will flatten out your foot, but it also allows you to “ankle” (use your ankle to add a bit of force to the stroke).
So here’s a perfect pedal stroke. For this example, we will be showing the right leg. See diagram as a reference. Graphic Source: A qualitative analysis of the biomechanics of the proper pedal stroke, Grant Bullock, Davon Cabraloff, Jessica Hickman, Mark Mico, Laura Nethcher and Dan Ward, March 9, 2009.
Power/Pushing phase – from about 12 o’clock to 4 o’clock. This is where you are engaging all of your pushing muscles: glutes/hip extensors, quadriceps, etc. The pushing phase is divided between the hip extensors (glutes) and the knee extensors (quadriceps). The glutes are used from about 12 o’clock to about 3 o’clock, where, at this point, the quadriceps take over and are in use from about 3 o’clock to almost 6 o’clock.
Transition (BDC) = bottom dead center – i.e., after pushing but not yet pulling. This is where you are ankling. You use your ankles, which are fired by the calf muscles, to get you through this “dead spot” where neither the pushing muscles nor pulling muscles are engaged.
Recovery/Pulling phase – through the bottom of the pedal stroke, i.e., entering the pulling phase. You are now engaging some ankle dorsiflexors but primarily the knee flexors / hamstrings.
Transition (TDC) = top dead center – i.e., after pulling but not yet pushing. This is where you are ankling to place your heel down so that you can generate leverage early / as soon as you enter the power phase. The primary muscle group you are using during this phase is the ILIOPSOAS (PSOAS, aka hip flexors). This muscle group is used through the entire TDC transition phase.
I hope this helps with the understanding of the dynamics of a pedal stroke. Lots of different muscle groups are activated and de-activated during 1 revolution of the crankset. Now that you know what muscle groups are in use, it’s time to stretch and strengthen them.
Coach Rick Schultz is an avid cyclist who trains, races and coaches in Southern California. Rick is an engineer by trade, and in addition to being a coach, he’s a bike fitter and prolific product reviewer. He’s the author of Stretching & Core Strengthening for the Cyclist in the RBR eBookstore. Check his product reviews website, www.biketestreviews.com, and his coaching site, www.bikefitnesscoaching.com. Click to read Rick’s full bio.
It is nice to see K.O.P.S. defended here. It makes the most sense to me.
Another method to set fore/aft is the “hands-off” test. (With your hands on the drops, while pedaling, you see if you can take your hands off the bar and still be able to hold your upper body up. You set the saddle as far forward as you can while still being able to do that. If you can’t, the saddle is too far forward.) For me, that test places me pretty much KOPS.
Excellent article! When I started riding longer rides many years ago someone kindly recommended that I get a bike fit from a local physical therapist that was a former racer and now coach. The difference in my riding was incredibly. I could ride more comfortably for longer distances at a faster pace almost immediately. This was the best investment I ever made in cycling, far more important than the bike, group set, etc.
While you often see the “pulling” argument made for pedaling, I have seen numerous readouts from pedal-based power meters that show experienced professionals (and presumably the rest of us) are NOT pulling up on the pedals. The rising leg is resting and being pushed by the falling leg. Have I got this all wrong? I do occasionally pull up briefly on a climb when my cadence is low, but I’m very skeptical that anyone can “pull up” at 90-100 rpm.
Great article. When I get a new bike, I include the cost of a pro fitting in my budget. I recently moved to a new bike that had significantly different frame geometry and initialing set the bike up with the same measurements (Top of seat to center of bottom bracket, pressure point of the saddle to handlebar cross-piece, with my knees over the center of the pedal axle when at the 9 – 3 o’clock position. Basically a triangle. However the angles of the sides of the triangle had changed. After about 30 days of riding, I got in for my fitting. Garmin Power Meter was reporting L-R balances between 55% -45% to 52% – 48%. My previous bike was 51% – 49% to 49% – 51%. consistently. After flitting, new bike is back in the same power distribution range. In addition, my FTP went up almost 12%.
I have always been suspicious of the circular power application. Not sure the human body is designed to apply equal power around a circle for best efficiency. Clearly, lifting the trailing leg helps relieve the pressure of the leading leg allowing those muscles to contribute to forward motion more efficiently. But where is the documentation that says uniform power is the most efficient for the human body. In the 70’s and 80’s, “ankling” became a buzzword with more efficient cycling. But does it make sense to have the same pressure perpendicular to the crankarm for the full stroke. A stroke that allows the maximum muscle usage for that muscle at its point of engagement would seem to create a more efficient stroke than one that is uniform in a circular motion. This is not to suggest that the maximum number of muscles available should not be engaged, but they should be used to their best efficiency in the appropriate sector of the stroke. In my gut, I have a feeling that this will not result in a constant power throughout the stroke, but since we only have two legs, there may be more combined power from both legs applied in the 2 – 4 o’clock position of each leg in the stroke than the 10 – 2 o’clock position. Not suggesting that power is not applied in the 10 – 2 position, just not equal. Not a physiologist, just an engineer and have no empirical data to support this position Seems like the major muscles in the leg work best in an up-down motion.
Almost certain this was the premise of the development of elliptical chainrings, to promote optimum muscle utilization.