SPD vs SPD-SL: Understanding the Binding Standards

Differences Between Shimano SPD and SPD-SL

Shimano’s SPD-SL is designed for road bikes, while SPD is tailored for mountain bikes (MTB), each reflecting a different design philosophy.

SPD-SL, developed specifically for road riding and racing, focuses on maximizing pedaling efficiency over comfort or ease of walking. In road racing, once clipped in, riders usually don’t unclip for several hours unless there’s an issue—so SPD-SL prioritizes power transfer over walkability.

In contrast, SPD, designed for MTB and cyclocross, assumes that riders will occasionally put their feet down or even dismount and carry the bike in tough conditions. Thus, SPD balances retention force with easier engagement/disengagement and walkability.

Power Transfer Efficiency

It’s often said that SPD-SL provides better pedaling efficiency than SPD. But how different are they really? Let’s look at the connection surface between the shoe, cleat, and pedal.

SPD connects via a roughly 3cm × 1.5cm area, while SPD-SL connects via a triangular area about 8cm × 7cm. This means SPD-SL offers an approximate contact area of 28cm² compared to SPD’s 4.5cm²—over six times larger.

Not all of that area is in contact with the pedal or shoe, but the difference is still significant. This larger interface helps distribute pressure and improve power transfer, especially during high-output pedaling.

Cleat-to-shoe connection also differs: SPD uses two bolts, while SPD-SL uses three, creating a more secure attachment between shoe and pedal.

Additionally, SPD-SL shoes often have rigid carbon soles, allowing the rider to push with the entire sole, rather than relying solely on the pedal contact point as with SPD or flat pedals. This contributes to better power transfer and overall pedaling efficiency.

Considering these factors, SPD-SL clearly offers more efficient power transmission compared to SPD.

Benefits of Better Power Efficiency

Assuming SPD-SL provides more efficient power transfer, what are the real-world benefits?

The main advantage is that it reduces fatigue (though it doesn’t eliminate it entirely). With SPD-SL, you can:

• Maintain optimal pedal contact throughout the stroke
• Utilize the upstroke thanks to the binding mechanism
• Benefit from less power loss due to a more stable connection

This means less wasted energy, allowing for more effective pedaling with less effort over time. As mentioned earlier, being able to push with the entire rigid sole of the shoe is a big plus for power efficiency.

Of course, switching to SPD-SL won’t magically eliminate fatigue, but on long rides over 100 km, many riders report feeling the difference—especially toward the end of the ride.

Difference in Ease of Engagement and Release

SPD cleats are smaller and generally easier to clip in and out, while SPD-SL systems are designed for stronger retention, making them a bit harder to engage and release.

This is why it’s commonly said that beginners should start with SPD, and then move on to SPD-SL as they gain experience.

However, even SPD-SL can be surprisingly easy to use—especially when using yellow cleats, which offer a wider float range and more forgiving disengagement.

When it comes to clipping in, SPD pedals—which are engaged by pressing down—are generally easy to clip into. On the other hand, SPD-SL requires you to hook in to the pedal, which can take some getting used to. At first, you might struggle to engage properly.

That said, it’s largely a matter of practice. And even if you’re not perfectly clipped in right away, you can still pedal without issue. You can also take a moment to fully clip in after setting off from a traffic light or sidewalk.

In that sense, the idea of choosing between SPD or SPD-SL based purely on ease of clipping in or out isn’t very compelling.

Difference in Walkability

Outside of power transfer and pedaling efficiency, walkability is a major difference between the two systems.

SPD-SL cleats are exposed and slippery, which can make walking feel awkward and unstable—especially until you’re used to it. It’s almost like walking on slick plastic blocks.

SPD cleats, however, are recessed into the sole of the shoe, so they don’t come into direct contact with the ground. Some SPD-compatible shoes even raise the sole enough that the cleats don’t touch the ground at all, making them feel very close to normal walking shoes.

That’s why even among road cyclists, many choose SPD shoes—especially if they enjoy touring, sightseeing, or use their bike for commuting. The ability to walk comfortably becomes a big plus.

Difference in Cleat Wear & Durability

When you start using clipless pedals, one surprising factor is how quickly cleats wear out.

SPD-SL cleats are made of plastic, and even if you’re only putting your foot down occasionally at stoplights, they can wear down quickly. It’s common to suddenly realize that the grip portions have disappeared, which makes clipping in/out harder and less secure.

In contrast, SPD cleats are made of metal, and because they’re not exposed to the ground, they hardly wear down—even with regular use. Unless something extreme happens, they remain functional for a very long time.

So if you’re looking for long-term durability and lower running costs, SPD is far more cost-effective and user-friendly as a binding system.

Types of Cleats

Types of SPD-SL Cleats

SPD-SL cleats come in three types, each color-coded and offering different levels of float (side-to-side movement). The more float, the easier it is to release your foot.

Note: With SPD-SL, more float means your foot can move side to side even while clipped in. While this provides comfort, it can reduce pedaling efficiency if you’re not used to keeping your stroke straight.

The yellow SH11 cleats offer the most float and are the easiest to release, comparable to SPD in that regard.

Types of SPD Cleats

SPD cleats come in two types: Normal and Multi-Release. While all SPD cleats are relatively easy to disengage, the Multi-Release version allows for disengagement in multiple directions. This makes them ideal for those who might be nervous about getting stuck.

Which is Better: SPD or SPD-SL?

When choosing clipless cycling shoes, many riders wonder whether to go with SPD or SPD-SL. However, it’s not that one is better than the other — they serve different purposes.

SPD is designed for MTB and rides where frequent clipping in and out is necessary. SPD-SL prioritizes pedaling efficiency, even at the cost of walkability.

For long-distance rides over 100 km, where you spend significantly more time pedaling than walking, minimizing power loss becomes more important, making SPD-SL the better choice.

On the other hand, for shorter rides around 20 km with frequent stops at cafes or tourist spots, you’ll be spending more time walking. In such cases, SPD is more convenient and comfortable. SPD also has the added benefit of not damaging shop or facility floors since the cleats are recessed into the sole.

Do You Have to Use SPD-SL on a Road Bike?

You may hear people say, “It’s not a real road bike unless you use SPD-SL,” but that’s not true. Whether you use SPD, SPD-SL, or even flat pedals, a road bike is still a road bike.

SPD-SL is certainly aligned with the concept of making long rides more comfortable, but it’s not a requirement. The best choice depends on your riding style and how you plan to use your bike.

Are SPD Shoes Like Regular Sneakers? Is SPD-SL Hard to Walk In?

SPD shoes are easier to walk in compared to SPD-SL, but they are still not like sneakers. They have cleats and stiff soles that make the walking experience quite different.

While SPD-SL cleats are plastic and offer little grip, SPD cleats are recessed and often come with thicker soles that prevent contact with the ground — making them less slippery and more walkable. However, SPD-SL is still walkable; it just wears down more quickly if used on asphalt or other hard surfaces.

Can You Convert Between SPD and SPD-SL?

Shimano offers an adapter (SM-SH40) that allows SPD cleats to be used on SPD-SL shoes. So it’s possible to convert SPD-SL shoes to accept SPD cleats. However, the reverse is not possible — you can’t use SPD-SL cleats on SPD shoes.

On the pedal side, there are no such adapters. You cannot convert an SPD pedal to SPD-SL or vice versa.

Are There Dual-Use SPD/SPD-SL Pedals?

While there are dual-use pedals that combine SPD and flat sides or SPD-SL and flat sides, there are no pedals that support both SPD and SPD-SL in one unit.

However, some shoes are compatible with both SPD and SPD-SL cleats. This allows you to change pedals without needing new shoes. The downside is that on dual-compatible shoes, the cleats are not recessed like dedicated SPD shoes, making them less effective for SPD setups.