What is the width of the pedaling posture, often called "stance width" ?

You've probably heard an experienced cyclist or coach suggest that a cyclist tuck their knees in while pedaling? Unfortunately, for many people, even athletes, simply pedaling too narrowly contributes to discomfort or decreased performance. At the top of the pedal stroke, the knee isn't under the same pressure and can naturally move outward to approach its ideal, comfortable position. The knee will then faithfully follow the foot into an uncomfortable position, forcing it inward to the 6 o'clock position. This blog post aims to explain the factors involved, the optimal timing for adjustments, solutions, and our recommendations based on years of experience in bike fitting. Before we go any further, make yourself a cup of coffee and let's review the terminology we'll be using in this article:

Stance Width

It's very difficult for me to fully translate the words "stance" and "width," but let's say it refers to the distance between the center of the right pedal's contact point and that of the left pedal. We could summarize it as the width of the pedaling posture.

Q Factor or Q Factor

The distance between the outer edge of each crank arm where the pedal is attached. This contradictory measurement is often too narrow on a road bike.
Q-factor on road bikes: Many Shimano cranksets have a 146mm diameter
Campagnolo 145.5mm
Q-factor on Mountain Bikes: the majority of Sram and Shimano cranksets are 168mm
Q-factor on a Fat Bike: 200-230mm
As you can see, this measure varies enormously depending on the discipline practiced.

Pedal axle length

Being largely uniform across the industry (like the q factor), this is the best place for posture width customization.

Let's look at some common road bike pedal axle widths:

Shimano Ultegra 8000 and Dura-Ace 9100 – 52mm (option + 4mm = 56mm)

Look KEO – 53mm (they have a 2mm longer thread area allowing the installation of spacers.

Speedplay – Zero Titanium – 50mm Zero Cr-Mo and Zero Stainless Steel – 53mm (Custom lengths available for Zero Stainless Steel: 50mm, 56mm, 59mm and 65mm)

Note that the Speedplay Zero is the pedal with the greatest range of adjustments on the market.

When do you need to change the width of your pedal stroke?

While no clear trend has emerged in the cycling industry, it's hard to believe that a majority of men and women of varying heights would be suited to a 252mm pedal pattern width (a measurement obtained by adding a Q-factor of 146mm to twice the axle length of the best-selling 53mm pedal). In our opinion, these "one size fits all" measurements are more akin to a few individuals than a majority. Without delving into the intricacies of rider positioning, a saddle height that's too low can accentuate knee protrusion during the upstroke. That said, if your knees protrude at the top of your pedal stroke and then cave inward at the end, you likely need to make adjustments to your knee alignment.

Stance Width: What are the possible solutions?

To resolve knee problems and achieve maximum comfort, the foot must be aligned with the knee – not the other way around. Therefore, the foot needs to be adjusted/repositioned. Here are some solutions:

1.) Longer pedal axle.

Don't hesitate to get pedals with longer axles, such as Ultegra +4mm or Speedplay with custom axles. However, it's strongly recommended to consult a professional bike fitter before making any changes, as this solution may not be sufficient.

2.) Push the wedges in as far as possible to allow the foot to move outwards.

This is an advantageous and low-cost solution, however it will only allow you to gain a few millimeters on each side and the weight exerted on the outside of the pedal can lead to discomfort on the outside of the foot if the cleats and/or pedals are slightly worn.

3.) 1.5 mm pedal spacer washers

These small spacers allow you to add between 1.5 mm and 3 mm to your pedaling width. We recommend adding a maximum of two if your cranks are made of alloy, and only one if your bike has carbon fiber cranks. That said, if you have Look pedals with longer threaded axles, feel free to install two.

4.) 20mm pedal extensions

Based on the previous equation with Shimano cranks, we get 292mm. Considering that the Q-factor of a mountain bike is 170mm, adding 40mm to a road bike is likely to help many cyclists achieve their desired comfort and alignment.

5.) A combination of the 4 previous solutions

Indeed, very often (read: 99.99% of the time), during your bike fitting session, several of these solutions will be used together to achieve perfect alignment and complete respect for your pedaling pattern. Take the example of a cyclist who might need to increase the axle length on the right but not on the left? The bicycle is a symmetrical machine, while the human body is not; moreover, we age, often lack coordination, or are unbalanced. Consequently, when we are attached to a symmetrical machine, problems arise, and each leg must be adjusted individually and independently of the other.

Conclusions and final thoughts

Our experience shows us that adjusting a cyclist's position is somewhat subjective. Therefore, what's perfect for cyclist A might be terrible for cyclist B. Pedaling pattern and stride width are worth examining for all cyclists. If you're out of alignment and pedaling at 85 revolutions per minute, you're making 5,100 pedal strokes per hour per leg. Considering that the average cyclist rides 6 hours per week, that's over 122,000 pedal strokes per month and over a million per year for each leg! With that many strokes, the pressure and stress on your joints, especially your knees, are considerable. Undoubtedly, your performance and comfort depend on properly adjusting your posture on your bike, but before booking an appointment with a bike fitter, ask them if they analyze your stride width and how they go about making the necessary adjustments. If you have any questions about the fit or width of the posture, please feel free to write or call us.

Note: It is strongly advised against attempting these types of adjustments yourself. To schedule an appointment with one of our experts…

 Enjoy the season!! - Yannick Perreault , Fitting Expert - Studio Cycle Maglia Rosa