Foot Function in Cycling: A Deep Dive into Biomechanics and Insoles with Neill Stanbury

In bike fitting, we often talk about saddle height, reach, crank length or cockpit setup. But beneath all of that lies a foundation that directly connects the rider to the bike: the foot. As the main point of force transfer, the foot plays a crucial role in how stable, controlled and symmetrical a position on the bike can be.

Foot shape, arch behavior, cleat setup and support structures inside the shoe are all part of a system that can influence not just comfort, but also function. And yet, the foot is a complex area with less visual feedback than pelvis or knee movement, and often requires a trained eye to interpret subtle patterns.

To take a closer look at how the foot functions in cycling and how support needs can be assessed, I sat down with physiotherapist and experienced bike fitter Neill Stanbury. In this conversation, we explore how foot mechanics interact with the rest of the body, how support can be adapted over time, and why foot-related issues sometimes show up in places you wouldn’t expect.

NK: The foot plays a central role in overall stability, power transfer and posture on the bike. That’s why I always include a detailed foot assessment in every fitting, not only looking at length, width, mobility and asymmetries between left and right, but also at foot shape. Whether the forefoot is more pointed or square, whether the metatarsal heads are prominent, and whether there are any anatomical abnormalities such as a developing hallux valgus. Still, I often feel that the foot gets less attention than other areas like saddle position or cockpit setup.

How do you see the role of the foot in the overall fitting process, and how do you approach foot-related assessments in your own work?

NS: Your approach mimics mine closely. The foot is easily the hardest part of the bike fit complex to get really nailed down to perfection, with the huge individual variation in foot types, shapes, structure and function, it can be a nightmare to get the foot setup perfect for each individual rider. This area is probably the single most challenging in bike fitting in my experience, there is a lot going on in a foot that you can’t see, neurological dominance, different levels of reliance upon arch support, first ray load, lateral arch stability and so on for each individual rider that it makes for a sometimes very difficult puzzle to solve. Then there are the riders who can wear pretty much any shoe, with no arch module of any type, and they have zero issues! Such is the variety of the human experience. 

I tend to look for the same types of issues in the feet, shape, structure, asymmetry and so on, but I will add two more that really stand out to me:

1. Rearfoot stability. This one is really, really poorly understood and poorly managed by most fitters. In particular, rearfoot laxity due to inversion sprains can widen the ankle mortice, leading to lateral and longitudinal instability in the talo-crural and subtalar joints. Apart from the obvious mechanical implications of rearfoot eversion at heel strike, this process seems to destroy a lot of the sensory acuity of the rearfoot complex, with severely diminished proprioception being the outcome. These riders will often drop one hip or sit assymetrically on the seat due to poor sensory perception of the location and orientation of their affected foot, with consequences significantly further up the kinetic chain often being the outcome. The solution is usually twofold: A very tight, stable heel cup on the shoe helps a lot, as does heel wedging in 1-4 degree increments.
2. Plantarflexed or dorsiflexed first rays. This inclination of the first ray to “sit up” or “sit down” as viewed from the front of the foot when non weight bearing can be a really tricky trigger of higher-order asymmetry in the rider. If the first ray is plantarflexed, often the leg will drive into varus, pushing the knee away from the top tube of the bike and vice versa with the (much more common) dorsiflexed first ray deviating into valgus and pulling the knee inwards. These are solved well with 1st ray cutouts or posts in the orthotic building phase of the fit session, but often they are missed and the resultant asymmetry frustrates the fitter along the way. 

I therefore tend to look primarily for these two big issues when chasing down problems with pedal stroke control and asymmetry. A comprehensive foot assessment at the start of the session can help prevent a lot of problems further down the line!

"The foot is easily the hardest part of the bike fit complex to get really nailed down to perfection, with the huge individual variation in foot types, shapes, structure and function, it can be a nightmare to get the foot setup perfect for each individual rider."

Neill Stanbury, Professional Bike Fitter

 

NK: I definitely agree. Rearfoot stability and first ray position are key factors that are too often missed, yet can have a major impact further up the kinetic chain. From my experience, wedging is a highly effective way to address these issues. Anyone who's curious to explore the rabbit hole of wedging, we've put together an article on it's purposes and benefits.

You can check it out here.

In cycling, the foot doesn’t experience a natural gait cycle. There’s no heel strike, no midstance and no toe-off, largely to the stiff carbon or hard-plastic sole of the cycling shoe. As a result, the typical mechanisms that activate and stabilize the arch, like the windlass effect, don’t really come into play. It is important to take a close look at how the foot behaves under load, not just statically, but dynamically within the constraints of the cycling shoe. Some riders, despite stiff soles, show clear signs of medial arch collapse during pedaling due to hypermobility or reduced muscular control.

How do you think about foot function in this context when you're evaluating support needs?

NS: You are once again correct in all regards here, no arguments from me. If the rider has particularly mobile ligament systems, poor neuromotor control and single leg balance, or a history of major ankle sprain/injury then the importance of these factors is magnified. There are also those riders at the other end of the spectrum with rigid, solid arched feet who can function in just about anything without seemingly any consequences!

I like to start with an arch module that supports the entire arch, potentially with a small bias towards the rear of the arch curvature. It should feel solid, almost too heavy for the rider upon initially jumping on the bike after fitting them. If the rider forgets about the insoles after 15 mins of riding, you know you have done a good job with the arch support level, they should feel solid and stable but not painful or intrusive.

The importance of the heel cup is not to be under-estimated. In my experience there is no possible way you can have too much heel cup stability on a cycling shoe, there are only positives to come from really stabilising the back half of the foot significantly. This concept was really driven home to me in the last 12 months using the Lore1 and Lore2 custom shoes from the USA. These are by far the most rigid cycling shoe ever made, and the heel cup is custom made and printed to match a 3D scan of your foot. The rearfoot stability is so incredible in these shoes that no arch module is required at all, all of the stability comes from the rearfoot, they are very impressive. In a normal shoe with some heel cup laxity, an arch module that matches the foot cleanly and stabilises the forefoot and midfoot is a necessity for a huge majority of riders.

I tend to look for the subtle signs of unusually high pelvic rock, and medial “whip” of the knees at the bottom of the stroke towards the midline of the bike as the primary visual cues of insufficient or improper arch/rearfoot stabilisation. Resultant compensatory asymmetry is pretty much standard operating procedure when the feet aren’t “right” so this is another thing to look out for – unexplainable asymmetry!

NK: Custom-made insoles are often seen as the gold standard when it comes to tailored arch support and in many cases, that’s absolutely valid. But from my experience, they’re only truly effective if they’re reassessed and refitted regularly, since the foot can change due to training, injury, footwear habits or altered neuromuscular control. I find that many athletes hesitate to invest in repeated custom refits, even when it would be biomechanically ideal. Cost becomes a limiting factor, especially for those without chronic issues or access to medical reimbursement.

That’s one reason I often work with modular systems like G8 Performance insoles. They allow for ongoing adjustment as the athlete evolves, without requiring a completely new insole each time. This adaptability makes them a practical and accessible solution in many settings. Nevertheless, the choice of the right cycling insole is highly individual and should always be determined on a case-by-case basis, whether a standard insole, a modular system, or a fully custom insole is the best solution depends on the rider’s specific needs and foot mechanics.

How do you navigate this balance in your own practice? In which cases do you find modular systems like G8 sufficient, and when do you feel a fully custom or even clinical orthotic solution is necessary, despite the challenges around long-term cost and compliance?

NS: I would tend to generally agree with this, I see feet that have changed significantly year-on-year relatively regularly. The G8 style module is great for this, you can move the arch module around, and change the height of it as needed. You can also snip parts away with scissors, or add small layers of EVA foam to the underside to alter the pressure through various sections of the orthotic as needed. Great if you like tinkering with your bike setup!

The flip side of the coin is that the arch module does tend to collapse over time and require replacement fairly regularly, effectively meaning a new set of orthotics every 1-3 years depending on how aggressively the rider destroys them. I often think that an insole with a 5-10 year lifespan which can be modified lightly here and there with foam additions for example is a better bet in terms of cost-benefit ratios for the majority of people. In addition, feet most of the time don’t change huge amounts, there are the outliers which can change a lot, but mostly they are static enough in a 3-5 year time range that the majority of people should be OK to run the same insole set for that length of time. 

A full custom insole can also be tweaked and altered by the podiatrist who created them, additions, wedging, metatarsal domes and the like can all be altered and the machined arch module re-covered with relatively low cost, so there are pros and cons to each method. The only way to navigate these issues is on an individual basis, if the rider starts to feel something has gone “off” in the insole setup over time, we get them back in the clinic for a follow-up and see what needs to be altered.

"Subtle changes in foot posture can trigger compensations further up the chain, especially when combined with factors like poor cleat positioning, missing wedging, or a lack of appropriate spacers."

Nils Kehrberg, Professional Bike Fitter

 

NK: In many of my bike fits, riders don’t report any discomfort in their feet. No pain, no hotspots, no numbness. Instead, they struggle with symptoms like lateral movement or instability on the saddle, asymmetric knee tracking, or general difficulty maintaining a balanced and efficient position. In these cases, I often find that the root cause lies in insufficient foot support, particularly a collapsing medial arch or rotational instability during the pedal stroke. These subtle changes in foot posture can trigger compensations further up the chain, especially when combined with factors like poor cleat positioning, missing wedging, or a lack of appropriate spacers.

How do you approach these kinds of indirect symptoms in your own fitting practice? What are some of the clearest indicators that a rider might need arch or midfoot support, even if the feet themselves feel fine? And when riders don’t have access to a full fit session, what would you consider as a simple way they can assess foot mechanics and make an informed decision between a neutral, modular, or custom insole?

NS: Again, this closely mimics my experience in general terms, hence why we spend so much time and effort getting the shoe and insole setup perfect at the start of the fit session, and adjusting it as we go along through the fit session to assess the effects of various changes. 

The clearest indication of insufficient or improper arch support is pretty much always unexplainable asymmetry. Typically this will involve the rider dropping their right hip forward and down, and their pelvis twisting assymetrically on the saddle to favour their dominant leg. The resultant pelvic asymmetry will dramatically improve when the arch support, cleat wedging, heel wedging and such is all optimised. 

A secondary indicator is the classic medial femoral “whip” that riders get at the bottom of the stroke as the arch pronates through the power phase of the stroke, you will often see medial arch collapse leading to the knee whipping across towards the top tube on one or both sides. This is often a dead giveaway that something isn’t right, however you can get the same effect from other sources as well.

Pro-Tip @home:

If you are attempting to sort out your own insole setup, you can take a short video of yourself with a high-resolution camera phone. Walking towards, and away, from the camera whilst the phone is held at ground level will give you a good idea if your rearfoot is everting, the arch pronating or the midfoot collapsing for example. You should also be able to spot moderate amounts of asymmetry in the foot plant when walking and then set up some good quality insoles themselves, something like a G8 can be great for this as you can play around with the arch modules’ setup themselves to get it just right.

The most critical thing to look for in general terms is rearfoot pronation. If the calcaneum is everting/pronating seriously at heel strike, and the line of the achilles is tilted inwards into a valgus-style deviation as viewed from behind, then you will almost always do better with strong rearfoot and midfoot stabilisation, and heel wedging.

You can also get your significant other to hold your foot at rest and sight down along the long axis of the foot to determine if there is a marked forefoot varus. This is easy to do and if the heel and forefoot are drastically out of plane with each other, you can consider cleat wedging or first ray posting as something simple to test themselves at home. 

If you see an extremely unusual level of asymmetry in the foot plant, or you have serious trauma to one foot (in particular, Lis-Franc fracture/dislocations are problematic) then a custom insole is not a bad move, the podiatrist who makes the insole will be able to make a much more accurate judgement call on your foot mechanics, it’s pretty hard to assess your own feet if you have no prior experience with feet!

 

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Thanks to all co-authors: