February 6, 2020
Last modified: February 6, 2020

How To Find the Best Flat Pedal Size for You and Your Bike

For riding off-road, it seems that the modern-day masses have named flat pedals as king, queen and everything in between. They offer more support and freedom to adjust your footing at will, making them perfect for off-road touring, tough rocky climbs, or nasty root-crossed descents.

That said, the introduction of alternative pedal sizes has complicated things a bit, sparking debates about the best size for flat pedals. Some people say bigger is always better, while others insist a small platform that provides maximum clearance is ideal. So how do you determine the best flat/platform pedal for you?

At a Glance:

Before identifying your flat pedal size, it’s important to ask yourself a few questions about how you’ll use your flat pedals:

  • What terrain do you typically ride?
  • What size are your shoes?
  • How wide is your stance?

Why Pedal Size Matters

These considerations matter because there is no one-size-fits-all pedal for every rider. You have limited contact points with your bike, and just a few square millimeters of pedal space can make a massive difference — pedal size directly impacts how you and your bike perform together, and how comfortable and confident you feel while riding.

Larger Pedals

A larger pedal proves mandatory for folks with big feet, sure, but what about the rest of us? A giant platform provides the greatest stability and support for your shoes, which means comfort and control. However, bigger is not better for everybody! As the pedal gets wider, the likelihood of ground clearance concerns increases — you’ve got a greater chance of striking obstacles or dragging your pedal in the dirt around tight turns.

Small Flat Pedals

For a long time, people with smaller feet didn’t have many options for quality flat pedals. In fact, for some small-footed folk, big platforms reduce traction, because their smaller shoes don’t contact all the pins. And, as mentioned above, for those folks concerned with rock strikes who like to ride the berms at full speed, a smaller pedal gives greater margin for error with regard to ground clearance.

So for any rider, your choice in flat pedals should balance your riding style with the size and shape of your shoes.

Your Pedal Options with iSSi

At iSSi, we offer a selection different-sized flat pedals to help fit different types of riders. No matter what kind of riding you’re gonna do, getting solid footing from your flat pedals is the key to safety, control and effective power transfer. As a result, all of our flat pedals are designed with a central concavity that your feet can easily sink into. This spreads out your weight across the pedal’s entire surface area and helps the pins secure your footing from every angle.

The concave dip in the center of the Thump S.
All iSSi Stomp and Thump pedal models have center concavity

If the pedal doesn’t fit, however, you’ll find your feet either sitting on top of the pins and slipping off or sitting between them and sliding around inside the cavity; neither outcome is ideal. Finding the right pedal size can be difficult if you’ve never tried them before, but fortunately, there are a few ways to find your pedal size before you buy.

What kind of terrain do you typically ride?

Knowing how and where you’ll be riding will be the best compass to help you find the right flat pedal for the trip. When comparing different pedal options, you should consider what kinds of obstacles you might encounter and how you will approach them.

For downhill-like applications, the bigger is better mantra still holds some weight. Going big or racing down rough terrain requires big pedals with big traction. Consider a pedal like the Stomp XL for these types of scenarios — it’s one of the biggest flat pedals on the market.

If your riding leads you to a lot of off-camber trail, rocky climbs, or off-kilter situations in general, a more compact pedal like the small Thump with replaceable pins might be a better option.

What’s your foot / shoe size?

The first step toward finding the right flat pedal size is to compare them to your own shoes. Picking the recommended pedal for your shoe size will help optimize bike control and comfort without taking up extra clearance space.

iSSi flat pedal surfaces and pin placement. Millimeters matter!
iSSi flat pedal surfaces and pin placement. Millimeters matter!

Each of our flat pedals suits a range of shoe sizes:

  • Thump S: US Men’s 9 / Women’s 11 or under
  • Thump: US Men’s 9 / Women’s 11 and above
  • Stomp: US Men’s 9 / Women’s 11 or under
  • Stomp XL: US Men’s 9 / Women’s 11 and above

It is pretty simple on its face, but for those who fall on the borderline between each of these pedals, going one level deeper might help.

What’s your pedal stance width?

Finding where your feet naturally fall on the pedals can further refine your pedal fitment. Generally speaking, without getting into nuanced biomechanics, the balls of your feet should sit just forward and to the inside of the center of the pedal. Your knees should line up directly above your feet at the top of each pedal stroke.

An example of the ideal pedal stance width.
An example of the ideal pedal stance width.

A professional bike fitting from your local shop used to be the exclusive realm of clipless pedals and road bikes, but in recent years, some shops have started offering mountain bike specific fittings. They can help with stance width, but if you already have a pair of pedals that feel good on a bike that you like, you can use those to get an estimate. To do this, simply measure the distance from the outside of the crank arms to the center of each pedal and combine it with that bike’s Q-Factor (the distance between the outside of each crank arm). This will give you the number that you’ll be shooting for.

The effective Spindle Length measurements of the Stomp XL, Thump and Thump S.
The effective Spindle Length measurements of the Stomp XL, Thump and Thump S.

Spindle Length x 2 + Q-Factor = Stance Width

The overall size of each of our pedal designs slightly changes where your feet should rest on them. The way it’s measured is from the middle of the pedal to the crank arm.

  • Thump S is 59mm
  • Thump is 61mm
  • Stomp is 57mm
  • Stomp XL is 65mm

Once you’ve found the right-sized flat pedal for you, you might be interested in exploring your different pin options. Then all that’s left to do is choose the color that fits your own personality. But we don’t really know anything about that. We just make pedals.