Cleat spacers in bike fitting: millimeters that make the difference

For the first 45 minutes of our bike fitting, we're not on the bike at all. Instead, I look at the pelvic position, the spine, the shoulder girdle, the legs, and the feet to detect any abnormalities. We feel and poke our way through the body, and what we discover is by no means always pathological. Leg length discrepancies, for example, are not uncommon and are often functional rather than anatomical. So, the bones aren't different lengths; rather, poor posture such as pelvic tilt causes the legs to be displaced relative to each other. We discover such a leg length discrepancy in about every third or fourth bike fitting. Cleat spacers are an important and very helpful element. They help to compensate for asymmetries caused by leg length discrepancies and other abnormalities and to optimize the connection between rider and bike.

What exactly are cleat spacers?

Cleat spacers are millimeter-thin, cleat-shaped plastic plates. They are inserted between the shoe and the pedal plate system (cleat), thus changing the distance of the foot to the pedal spindle. The decision as to whether or not cleat spacers are useful depends largely on the rider's seating position and compensation strategies.

When are cleat spacers used in bike fitting?

During a bike fitting, we use cleat spacers when certain structural or functional issues are present. Common applications include:

1. Compensate for leg length discrepancy

Even a few millimeters of leg length difference, whether anatomical or functional, can lead to one-sided strain and a shifted saddle position. Over time, this can cause knee, pelvic, or back pain. Saddle problems are also often related to leg length discrepancies and the resulting asymmetrical sitting position on the saddle. A cleat spacer under the shorter leg helps to compensate and restore the system's equilibrium.

2. Asymmetrical kick or pelvic tilt

If the pelvis visibly rotates or tilts to one side while pedaling, a spacer under one side can help stabilize the hip and harmonize the pedal stroke. In combination with other setup adjustments, this can effectively compensate for pelvic misalignment.

3. Foot misalignments or pressure problems

A spacer can also be useful in cases of structural peculiarities such as flat, hollow or splayed feet or in cases of sensitive soles of the feet, for example to improve the pressure distribution under the foot or to correct the angle of the foot position.

Use with various pedal systems

We use cleat spacers in various pedal plate systems, both in road bike systems such as Shimano SPD-SL, Look Keo or Speedplay and in MTB and gravel bikes like Shimano SPD or Look X-Track. The key is always the combination of the right shoe, the right pedal, and a well-thought-out fit.

On road bike shoes, the mounting surfaces are often large enough for the spacers to fit securely. In MTB and gravel bikes, we pay particular attention to the security and stability of the screw connection. Spacers that are only mounted under MTB cleats are often very unstable and can also hinder clipping in. Sideways tilting of the shoe on the pedal can also be an unintended consequence of cleats in MTB and gravel bikes. One system that solves all of these problems is the Walkable system from Form in the UK. Thank you, Ronan, you little Gyro Gearloose, for solving this huge problem of the past few years!

Here you can find the MTB/Gravel Spacer System

Here you can find the road bike spacer system

This is how the bike fitting process works

A cleat spacer should always be used only after a thorough analysis of the musculoskeletal system and the individual bike position. Therefore, during our bike fittings, we always begin by carefully analyzing movement patterns and complaints.

Among other things, we check:

• Pelvic position and movement when standing, moving and kicking
• Visible and/or measurable leg length differences
• Saddle position
• Knee position
• Previous injuries or limitations
  

Only after all relevant factors have been considered do we test the use of cleat spacers in small increments, closely monitoring the effect. For very significant leg length discrepancies, such as several centimeters, adjusting with cleats often requires several sessions, with weekly intervals between individual sessions, to avoid overtaxing the body with overly drastic changes.

Conclusion: Small but effective

In the right cases, cleat spacers can be a crucial component for increased comfort, symmetry, and efficiency on the bike. If you regularly experience discomfort on one side only, your pedal stroke feels uneven, or you already know you have asymmetry, it's worth taking a closer look.