Arch Support and Cycling Shoes: The Overlooked Foundation of Power Transfer

Introduction

In discussions of cycling biomechanics, we spend a great deal of time on the knees, hips, and spine, yet we often overlook the starting point of power transfer—the foot. Every watt of pedaling power must pass through the foot to the pedal, and the structure and support of the foot directly affect the efficiency and stability of this transfer. A well-fitted pair of cycling shoes paired with the correct insoles may be the most underestimated performance enhancement available.

Foot Arch Anatomy

The Three Arches

The human foot has three arch structures:

1. Medial Longitudinal Arch

• Composed of the calcaneus, talus, navicular, cuneiforms, and the 1st-3rd metatarsals
• The highest and most prominent of the three arches
• Primary function: shock absorption and elastic energy storage
• Key supporting structures: plantar fascia, posterior tibial tendon, spring ligament

2. Lateral Longitudinal Arch

• Composed of the calcaneus, cuboid, and the 4th-5th metatarsals
• Lower and stiffer
• Primary function: provides a stable weight-bearing platform
• The primary pathway for weight transfer during walking

3. Transverse Arch

• Formed by the transverse arrangement of the metatarsal heads
• Most pronounced at the level of the metatarsal heads
• Primary function: distributes forefoot pressure
• Directly bears the pressure of the pedal spindle during pedaling

Arch Types

Arch height varies from person to person and can be broadly divided into three categories:

Type	Medial Longitudinal Arch Height	Plantar Contact Area	Characteristics
High Arch (Pes Cavus)	High	Small	Stiffer foot, poor shock absorption
Normal Arch	Medium	Medium	Optimal balance of shock absorption and stability
Flat Foot (Pes Planus)	Low or absent	Large	Softer foot, poor stability

Foot Mechanics During Pedaling

Power Transfer Pathway

During pedaling, the power transfer pathway is:

Hip Musculature → Thigh → Knee Joint → Lower Leg → Ankle Joint → Foot → Cleat → Pedal → Crank

In this chain, the foot is the final biological link. If the foot’s structure is unstable, power transfer “leaks” at this point—some energy is wasted on excessive deformation of the foot rather than being efficiently transferred to the pedal.

Foot Pressure Distribution During Pedaling

Studies using in-shoe pressure sensors have measured plantar pressure during pedaling:

Power Phase (1-5 o’clock):

• Pressure concentrated in the 1st-3rd metatarsal head region
• Peak pressure can reach 300-500 kPa
• The big toe and second toe bear significant pressure

Transition Phase (5-7 o’clock):

• Pressure shifts toward the heel
• Overall pressure decreases noticeably

Upstroke Phase (7-11 o’clock):

• Lowest pressure
• Mainly distributed across the instep (at the strap/closure area)

The Role of the Arch During Pedaling

During the power phase of each pedal stroke, when large forces are transmitted through the forefoot, the arch plays a critical role:

Stable Arch: Force is efficiently transferred from the rearfoot through the midfoot to the forefoot with minimal energy loss.

Collapsed Arch: The midfoot collapses medially and downward, absorbing some pedaling energy. Additionally, foot pronation propagates upward through the kinetic chain, affecting knee alignment.

Excessively Rigid Arch: While power transfer efficiency is high, adaptability is lacking. During prolonged riding, plantar pressure becomes overly concentrated, easily leading to hot spots and numbness.

Cycling Shoe Design Considerations

Sole Stiffness

The most distinctive feature of cycling shoes is their extremely stiff soles. This contrasts sharply with the flexible soles of running shoes, for the following reasons:

• Maximizing power transfer: A stiff sole prevents the foot from deforming during pedaling, ensuring nearly all muscular force is converted into pedal thrust
• Even pressure distribution: A stiff sole disperses the concentrated pressure of the pedal spindle over a larger plantar area
• Eliminating arch collapse: The rigid platform directly prevents excessive arch deformation

Sole stiffness is typically quantified using a Stiffness Index or Flex Rating. Top-tier race shoes typically have a stiffness index of 12-15 (out of 15), while entry-level shoes may range from 6-8.

But stiff does not equal better. For recreational riders and long-distance cyclists, moderate flexibility can:

• Provide better walkability
• Reduce plantar pressure concentration
• Increase comfort during long rides

The Importance of the Last

The last is the three-dimensional shape model of the shoe that determines how well it fits the foot. Cycling shoe last considerations include:

Forefoot Width: Shoes that are too narrow compress the metatarsal heads, causing nerve compression (Morton’s Neuroma) and forefoot numbness. During cycling, the forefoot bears sustained pressure, making width sensitivity even greater than in running shoes.

Heel Cup: A secure heel wrap ensures the foot does not slide inside the shoe. Heel slippage not only wastes energy but also alters the effective position of the cleat.

Toe Box Height: The toes need some room to move during pedaling. A toe box that is too low compresses the toenails and toe joints.

The Science of Insoles

Problems with Stock Insoles

Most cycling shoes come with stock insoles that are flat, thin foam pads. They provide almost no arch support, with the rationale typically being “the stiff sole itself is the support.”

But this logic overlooks an important fact: a stiff sole limits arch collapse from below but does not fill and support the arch space from within. The result is that the arch hangs suspended between the sole and the foot, requiring muscles and ligaments to work continuously to maintain the arch structure.

Advantages of Custom Insoles

Professional cycling insoles (such as those from Superfeet, Solestar, Sidas, and other brands) or custom-made insoles provide:

1. Medial longitudinal arch support: Fills the space beneath the arch, reducing the stabilizing workload of muscles
2. Metatarsal support: Provides elevation behind the metatarsal heads, helping to maintain the transverse arch
3. Heel cup: Stabilizes the calcaneus, improving overall foot alignment
4. Integrated forefoot wedging: Some insoles incorporate forefoot varus/valgus compensation

Research Evidence

Research on the effects of insoles on pedaling efficiency has yielded somewhat mixed results:

• Jarboe & Quesada (2003): Arch-support insoles reduced peak plantar pressure by 11%, but had no significant effect on power output
• Bousie et al. (2013): Custom insoles improved knee stability in the frontal plane
• Koch et al. (2013): Semi-custom insoles reduced perceived fatigue during a 45-minute ride

Overall, the primary benefits of insoles may not be a direct increase in power, but rather improved comfort, reduced injury risk, and maintained pedaling quality during prolonged rides.

Common Foot Problems and Solutions

Hot Foot (Forefoot Numbness)

This is the most common foot problem among cyclists, typically appearing 30-60 minutes into a ride.

Causes:

• Excessive pressure on the metatarsal head region, compressing the interdigital nerves
• Shoes that are too tight (especially in the forefoot area)
• Cleat positioned too far forward
• Lack of arch support leading to concentrated forefoot pressure

Solutions:

• Use insoles with a metatarsal button to shift pressure from the metatarsal heads to the metatarsal shafts
• Ensure the shoe has sufficient forefoot width (the foot swells slightly during riding due to increased blood flow)
• Move the cleat back 5-10 mm
• Check whether the closures are fastened too tightly

Plantar Fascia Discomfort

Causes:

• Insufficient arch support, causing excessive stretching of the plantar fascia
• Stiff soles lacking cushioning, subjecting the plantar fascia to direct impact

Solutions:

• Use insoles that provide good medial longitudinal arch support
• Perform self-massage of the plantar fascia before riding (using a golf ball or massage ball)
• Stretch the calf muscles to reduce tension on the plantar fascia

Achilles Tendon Area Discomfort

Causes:

• The shoe’s heel counter irritating the Achilles tendon
• Cleat positioned too far forward, causing excessive involvement of the calf muscles

Solutions:

• Choose shoes with a lower heel design that does not press on the Achilles tendon
• Move the cleat backward
• Strengthen the Achilles tendon with eccentric training

Bunion (Hallux Valgus)

Causes: Structural issue, but narrow shoes worsen the symptoms.

Solutions:

• Choose shoes with sufficient forefoot width (some brands offer wide-last versions)
• Use toe spacers
• In severe cases, consider localized heat molding of the upper

A Deeper Look at Forefoot Tilt

Forefoot Varus

This is the most common forefoot structural variation, with approximately 80% of people having some degree of forefoot varus. It manifests as a medial tilt of the forefoot relative to the rearfoot.

Impact on pedaling:
During pedaling, the medial side of the forefoot (big toe side) cannot make stable contact with the sole, forcing the foot to pronate to compensate. This pronation propagates upward through the kinetic chain, causing tibial internal rotation and knee valgus collapse.

Compensation methods:

• Medial wedge shims beneath the cleat
• Forefoot lift designs built into insoles
• Severe cases require custom orthotic insoles

Forefoot Valgus

Less common, but equally requires attention. It manifests as a lateral tilt of the forefoot.

Impact on pedaling:
The foot tends toward supination, causing pressure to concentrate on the lateral side of the foot, and the knee may drift outward.

Compensation methods:

• Lateral wedge shims
• Lateral lifts in custom insoles

Insole Selection and Customization Process

Semi-Custom Insoles

Semi-custom insoles available on the market (such as Superfeet’s different arch height options) offer a cost-effective solution:

1. Determine arch type: Through a wet footprint test or professional foot scanning
2. Select the corresponding arch height: High arches choose high-arch support, flat feet choose medium arch height
3. Test ride: Ride with the new insoles for at least 2-3 sessions, gradually increasing ride duration
4. Fine-tuning: If discomfort occurs, try different brands or arch heights

Fully Custom Insoles

Fully custom insoles are typically provided by professional bike fitting studios or foot specialists:

1. Foot assessment: Static and dynamic foot measurements, including arch height, forefoot tilt, and rearfoot angle
2. Molding: Using foam impression, plaster casting, or 3D scanning to capture the foot shape
3. Fabrication: Creating bespoke insoles based on individual foot shape and riding needs
4. Trial fitting and adjustment: Test riding after installation, with fine-tuning based on feedback

Fully custom insoles typically cost between NT$3,000 and NT$8,000, but for riders with persistent foot issues, this may be one of the most worthwhile investments.

Practical Shoe Selection Advice

1. Try shoes in the afternoon: The foot is typically slightly larger in the afternoon than in the morning, closer to its state during riding
2. Bring your own insoles: If you already have custom insoles, you should use them when trying on shoes
3. Forefoot space: Toes should be able to move slightly, but the foot should not slide inside the shoe
4. Heel lock: The heel should have no sensation of slippage inside the shoe
5. Test the closures: Try different tightness levels to ensure you can find a comfortable yet secure setting
6. Short test ride: If possible, do a 10-15 minute test ride before purchasing

Conclusion

The foot is the foundation of the cycling power transfer chain. A well-fitted pair of cycling shoes paired with appropriate arch support can not only improve pedaling efficiency but also prevent a range of problems from the soles of the feet to the knees and even the hips. If you have never taken the insoles inside your cycling shoes seriously, now is the time to re-examine this overlooked component. After all, a tall building rises from the ground—powerful pedaling output begins with stable feet.

Related Reading

• Flat Feet and High Arches: Their Different Effects on Running and Cycling, and General Principles of Insole Adjustment
• The Foot Is the Foundation of Your Sport: A Complete Coach’s Guide from Foot Function, Flat Feet, and High Arches to Insoles
• Running Insoles and Arch Support: How to Choose the Right Insoles for Yourself
• Running Arch Morphology and Plantar Pressure Distribution: A Kinetic Comparison of High Arches vs. Flat Feet