Everything You Need to Know About Q-Factor - MyVeloFit (2024)

Q-Factor, or the horizontal distance between the outside of one crank arm to the outside of the opposite crank arm, is a critical yet often overlooked aspect of bike fit. This measurement directly influences your stance width on the bike, essentially determining how far apart your feet are (aka stance width) when pedalling.

This post will go over everything you need to know about Q-Factor and how it affects your riding experience.

Everything You Need to Know About Q-Factor - MyVeloFit (1)

Why is Q-Factor important?

It’s all about alignment. A correct Q-Factor helps align your hips, knees, and ankles, reducing the risk of injury and increasing pedalling efficiency. If the Q-factor is too wide or too narrow for your body’s natural stance (and mobility), you can experience strain in your joints (often your knees), resulting in discomfort and which can lead to long-term issues.

The importance of Q-Factor lies in its ability to match your bike’s geometry to your body’s natural alignment. An incorrect Q-Factor can lead to discomfort, decreased efficiency, and potential injuries over time. It affects how you sit on the bike, your pedalling mechanics, and ultimately, your overall riding experience.

Common Issues from the Wrong Q-Factor / Stance Width

Q-Factor issues are often overlooked, and can occur with both a Q-Factor that is too narrow or too wide. Here are a few of the most common issues you might be experiencing that are related to improper Q-Factor and stance width:

Pressure on the Outside of Feet

Too narrow a Q-Factor can lead to excessive supination, causing pressure along the outsides of the feet. Some riders will mistake this for their shoes being too narrow.

Medial Knee Pain

Pain on the inside of (usually both) the knees, can often be due to insufficient stance width. This is often accompanied with knees that track outwards (away from the centreline of the bike) over the top of the pedal stroke.

Lateral Knee Pain

Pain on the outside of (usually both) the knees, can often be due to excessive stance width. This can often feel like IT band related pain.

Saddle Discomfort

A Q-Factor that is too narrow can result in an unbalanced saddle interaction (rocking or listing), affecting comfort.

These points highlight the need for adjusting the Q-Factor to ensure a comfortable and efficient riding experience.

How to Adjust Q-Factor and Stance Width

Your Q-Factor and stance width are made up of 4 key elements:

  1. Bike/frame (BB width)
  2. Cranks
  3. Pedals
  4. Cleat/foot placement

For all but the most committed of riders, changing your frame is unlikely to be a step you take when trying to dial in the right Q-Factor. However, it is certainly worth considering when shopping for a new bike. For most riders, this difference will be the most apparent between disciplines, with track, triathlon and TT bikes having the narrowest Q-Factors, next with road bikes, then MTBs, and for anyone that’s ridden a fat bike the Q-Factor is immediately noticeable as much wider. In general the wider the tires of the bike, the bigger the Q-Factor needs to be to accommodate.

Cranks also play an important role in determining your bikes overall Q-Factor, though similar to frames, this is a change that requires considerable commitment. So in practical terms, most riders will have to take their q-factor as a given for their bike, and seek to change their stance width via their pedal system and cleat placement.

The most simple way to adjust your stance width on the bike you have is to adjust your cleats on your shoes.

  • Move the cleats towards the inside of your foot to increase stance width.
  • Move the cleats towards the outside of your foot to decrease stance width.

For a full guide on how to set up your cleats properly, check out our post Cleat Positioning 101.

Pedal Q-Factors

As if there weren’t enough factors to consider when choosing a new set of pedals, many pedal systems also have different (though similar) width. While technically Q-Factor is measured as the distance between the outside of each crank arm, the width of pedals that contributes to your overall stance width is often also referred to as Q-Factor. Simply enough, the measurements listed are the added distance from the face of the crank arm (where the pedal screws into the crank), to the centre of the pedal body (which aligns with the centre of the cleat).

These listed measurements should be used as a baseline, a with many pedal/cleat systems there is a +/-2.5mm or greater amount of lateral cleat adjustment on the shoe to further fine tune your Q-Factor.

To make things as easy as possible, we’ve assembled all the most popular pedals in 2024 and listed their Q-Factors as provided by the manufacturers.

Shimano Pedal Stance Width

SPD-SL Cleats

Pedal ModelStance width (mm)
Dura-ace PD-R9100

Dura-ace PD-R9100 (+4)

52mm

56mm

Ultegra PD-R8000

Ultegra PD-R8000 (+4)

52mm

56mm

105 PD-R700052mm
PD-R55052mm
PD-RS50052mm

SPD Cleats

Pedal ModelStance width (mm)
XTR XC RACE PD-M9100

XTR XC RACE PD-M9100 (-3mm)

XTR Trail PD-M9120

55mm

52mm

55mm

XT XC RACE PD-M8100

XT Trail PD-M8120

55mm

55mm

PD-M54055mm
PD-ME70055mm
PD-M52055mm

Look Pedal Stance Width

Pedal ModelStance width (mm)
Keo Blade53mm
Keo 2 MAX (Carbon)53mm
Keo Classic 3 (plus)53mm
EXAKT54.6mm

Time Pedal Stance Width

ICLIC Cleats

Pedal ModelStance width (mm)
XPRO 15/12/1051mm

53mm

57mm

XPRESSO 7/4/253mm

ATAC Cleats

Pedal ModelStance width (mm)
SPECIALE 12/854mm
XC 12/8/6/4/254mm
MX 6/4/254mm
DH 454mm
LINK54mm

Wahoo/Speedplay Pedal Stance Width

Pedal ModelStance width (mm)
Nano Road53mm
Zero53mm, 56mm, 59mm, 65mm
Comp53mm
Aero53mm
Powerlink Zero Single/Dual55mm

Crank Brothers Pedal Stance Width

Pedal ModelStance width (mm)
Mallet Trail/Enduro/DH57mm
Candy 11/7/3/2/152mm
Egg Beater 11/7/3/2/152mm

Garmin Pedal Stance Width

Pedal ModelStance width (mm)
Rally RS100/20053mm
Rally RK100/20053mm
Rally XC100/20053mm

Assioma Pedal Stance Width

Pedal ModelStance width (mm)
Assioma PRO MX-1/253mm
Assioma UNO/DUO54mm
Assioma DUO-SHI64mm

Additional Resources

Justin Goulding

+ posts

Justin is a lifelong cyclist that has spent the past 20 years in the bike industry across a variety of roles. His diverse work in sales, procurement, and instructing is all driven by a desire to help more people experience the wonders of cycling. He brings this breadth of experience to building MyVeloFit into a company and service that not only provides bike fits, but one that enables more people to get the most out of cycling.

Everything You Need to Know About Q-Factor - MyVeloFit (2024)

FAQs

How do you know if your Q factor is too wide? ›

Knees kicking out during the pedal stroke can indicate a stance width that is too narrow, knees dropping in can mean the stance width is too wide. However, poor knee tracking can be due to factors other than stance width.

How to determine q factor cycling? ›

Q-factor is the distance between the outside of one crank arm and the other, measured not diagonally, but laterally, through the midline of the bottom bracket. Picture your crankset from above.

Does Q factor really matter? ›

Why is Q-Factor important? Q-Factor, or the horizontal distance between the outside of one crank arm to the outside of the opposite crank arm, is a critical yet often overlooked aspect of bike fit.

What does Q factor tell us? ›

In physics and engineering, the quality factor or Q factor is a dimensionless parameter that describes how underdamped an oscillator or resonator is. It is defined as the ratio of the initial energy stored in the resonator to the energy lost in one radian of the cycle of oscillation.

What should my Q factor be set at? ›

For most mechanical or electrical circuits, a Q of 0.5 is considered to be optimally damped. A Q of 0.3 would be over-damped, and a Q of 0.7 would be under-damped.

What is the most accurate way to measure Q factor? ›

An accurate Q value can be obtained from Q-meter that utilizes precise inductance coils that correspond to a specific capacitance range.

What is the average Q factor? ›

The Q factor is determined by the bike's chainstay length, chainline guidelines and lower bracket size, which are not easily customizable post-production. The average Q factor ranges from 150mm – 170mm.

What is ideal Q factor value? ›

Good high-Q capacitors can have a Q factor value of over 10,000 at 1MHz and over 1,000 at 100MHz, while standard capacitors can have a Q factor as low as 50 at 1kHz. The difference between a high-Q capacitor and a standard capacitor is in the actual design of the capacitor, as as well as the materials used.

What is the advantage of a high-Q factor? ›

High-Q factor resonators offer several advantages in biosensors. They provide high sensitivity and accuracy in detecting biomarkers, making them suitable for diagnostic applications 2. Additionally, high-Q factor resonators can operate in a label-free fashion, eliminating the need for additional labeling steps.

What is the importance of Q factor? ›

Bandwidth: When the Q factor or quality factor is increased then the bandwidth of the tuned circuit is decreased. When bandwidth is decreased then losses through the circuit are decreased, and the tuned circuit becomes shaper, and now more energy is stored in the circuit.

What does Q-value tell you? ›

The q-value is defined as the minimum false discovery rate at which an observed score is deemed significant. Thus, the q-value attempts to control the percentage of false positives among a collection of scores.

What does the Q factor depend on? ›

Q factor depends on L, C, R. Note::-Quality factor decreases with increasing resistance .

What does a large Q factor indicate? ›

Q-factor is the ratio of the center frequency (f0) to the bandwidth. High Q-factor transducer indicates a narrow bandwidth and a long spatial pulse length with low damping and narrow bandwidth. This commonly used in doppler ultrasound where a narrow bandwidth is needed to accurately quantify flow rate.

What is a wide Q factor EQ? ›

Bandwidth is usually called “Q” (for esoteric reasons from filter theory). Higher Q values affect fewer frequencies, and we refer to this as a “narrow” filter. Low Q values, on the other hand, yield “wide” filters that affect many frequencies.

What is a high Q factor? ›

The quality (Q) factor of a resonance describes the damping of its oscillation. It is defined as the ratio of the resonance's center frequency to its half-power bandwidth. A high Q value indicates low damping and energy loss at a lower rate. In such instances, the resonance may be referred to as underdamped.

What do you know about bandwidth and Q factor? ›

Bandwidth: When the Q factor or quality factor is increased then the bandwidth of the tuned circuit is decreased. When bandwidth is decreased then losses through the circuit are decreased, and the tuned circuit becomes shaper, and now more energy is stored in the circuit.

References

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