Shimano SPD vs SPD-SL Pedals – Which One to Choose
Bicyclists in a variety of disciplines frequently choose the SPD and SPD-SL clipless pedals from Shimano. This article will explain the two different Shimano clipless pedal systems and which one is most likely to suit your riding style.
Pedal systems from other manufacturers will also be briefly discussed. Although the terms “SPD” and “SPD-SL” are specifically used to refer to Shimano’s road and mountain bike pedal systems, they are frequently used to broadly refer to similar systems from other brands, even if they are incompatible with one another.
Because they have largely replaced the older system of toe clips and straps, used by road racers like Eddy Merckx, these pedal systems are known as “clipless.” In a clipless pedal system, the pedal has a locking mechanism that secures it to a cleat screwed into the bottom of the shoe.
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What’s the Difference Between SPD and SPD-SL?
Shimano Pedaling Dynamics is known as SPD, and SuperLight is known as SL. That suggests how the systems are supposed to be used.
While SPD pedals have largely come to be associated with mountain bikes (and more recently, gravel bikes), SPD-SL is primarily used for road cycling, which is where the lighter weight comes from. However, there are valid arguments in favor of using SPD pedals with a drop-bar bike.
We’ll get to the specific distinctions, benefits, and drawbacks of the two systems later.
The component of the system known as SPD cleats—which attaches to the bottom of your shoe and “clips in” to the pedal—is made of metal and is smaller than SPD-SL cleats.
The SPD cleats are frequently referred to as “two-bolt cleats” because they attach to the shoe with two bolts. Three-bolt cleats are another name for SPD-SL cleats, which have three points of attachment to the shoe. To reduce their weight, they are made of plastic.
There are additional effects of the design variations; continue reading.
A Bit of History
In 1984, Bernard Hinault, a five-time Tour de France champion, used a clipless pedal system created by French company Look. Look initially had a monopoly on road bike clipless pedals thanks to patents on its design; it is still Shimano’s main competitor in this market today.
The Dura-Ace 7401, Shimano’s first clipless pedal, debuted in 1987 and featured a licensed Look-compatible cleat.
Shimano then developed the SPD-R design, but they didn’t settle on the SPD-SL until the 2003 model year and the introduction of the 7750 Dura-Ace pedal, which was developed with input from Lance Armstrong.
Shimano had created the SPD design in the interim, which was first made available in 1990 and was based on a smaller metal cleat with two points of attachment to the shoe. Pedaling efficiency is crucial for performance road use, so while this was a natural fit for mountain bike riders, it didn’t work as well for them.
SPD Pedals Pros and Cons
Pros
- Double-sided design for easy engagement
- Excellent mud-shedding, less prone to clogging
- Walkable cleats and shoes
- Suited to a variety of riding disciplines
Cons
- Smaller contact area between the cleat and shoe
- Greater likelihood of foot ‘hotspots’
- Generally heavier than SPD-SL at a given price point
SPD-SL Pedals Pros and Cons
Pros
- Large contact area
- More direct feel
- Lighter than SPDs
Cons
- Single-sided entry
- Difficult to walk in
- Cleats wear more quickly than SPD
Why Use SPD Pedals?
Double-sided Entry
Being able to clip into either side of the SPD pedal makes starting from a stationary position much simpler. The majority of SPD pedals are double sided.
The small screw at the back of the pedal (one on each side because they are double sided) can be used to change the release tension of the cleat. Although some riders prefer the added security that comes with higher release tension, if you’re just getting started, you might prefer lower tension.
The majority of cleats provide some “float” in the shoe to pedal interface, allowing your feet to rotate about a vertical axis without disengaging, making the ride more comfortable.
Since all SPD cleats are made of metal, they are durable, but you may find that after a few years of use, wear to the binding surfaces makes engagement less secure. Replacements are inexpensive and simple to locate.
Two-bolt cleats have limited in-cleat side-to-side adjustment in addition to a range of fore-and-aft adjustment. Shimano
The mounting hardware is located on a separate plate inside the sole of the shoe, which allows for some adjustment of the cleat position on the shoe. The cleat’s bolt holes are made to give you some flexibility in where you place it.
The SPD cleats SH51/SH52 from Shimano and the multi-release SH56 cleat, which releases from the pedal when you twist your heel both upwards and outwards, are both available for purchase.
The former is more secure, but the latter makes disengagement a little bit simpler.
Unbelievably, Shimano also offers a few single-sided SPD models in its line-up, such as the Ultegra (PD-ES600) road pedal, which is intended for riders who prefer an SPD cleat interface to one with a wider platform.
These, however, are uncommon, and the majority of Shimano’s selection of road pedals employ the SPD-SL design.
Walkable Cleats
The small SPD cleat’s key benefit is that it’s simple to walk into when you get off the bike.
The majority of shoes for two-bolt cleats have a tread on the sole, and the cleat is recessed, so walking on the bottom of the shoe instead of the actual cleat is what you’re doing (as is the case with the SPD-SL design).
SPD pedals make sense if you anticipate doing a lot of walking. The sole’s tread prevents slipping on smooth surfaces and provides lots of grip when riding off-road and walking or climbing.
As you will frequently stop at traffic lights and walk to bike racks at the start and end of your commute, SPD pedals are a good option for cycling to work as well. Additionally, they work well with touring bikes when you need to be able to move around when stopping.
Mud-shedding
SPD pedals are made to shed mud because they are used off-road.
The majority of SPD pedals have an open design with a wide center gap so that any mud that collects on the bottom of the shoe will fall off and not hinder pedal engagement or pedaling effectiveness.
SPD pedals are an obvious choice for both mountain biking and cyclocross racing because of their walkability and resistance to clogging. Riders of gravel bikes also frequently use them, and the newest gravel shoes now support SPD.
If you’re hesitant to switch from flat designs to clipless pedals for casual use, SPD pedals are a good option.
For cold and wet riding when muddy, wet, or icy surfaces are common and there’s a higher chance that dirt will be kicked up by your wheels to clog your cleats, roadies should think about investing in a set of winter SPD boots and pedals.
To maximize mud-shedding, Shimano produces some SPD pedals with a very small surface area. There are also designs where the pedal has more of a platform, which increases the size of the interface with the shoe sole and makes it simpler to ride with the shoe resting on the pedal without clipping in.
To improve the shoe’s contact with the pedal surface, place tiny shims between the cleat and shoe.
What Are the Benefits of SPD Pedals?
Simple two-sided engagement
The double-sided design of SPD pedals, which is identical on both sides, may be their best attribute. As the pedal will always be available, this removes the element of uncertainty from using it.
Tension adjustment
The ease with which you can twist your foot to disengage from the pedal can be altered by adjusting the release tension screw on the back of the pedal. To gain confidence and make disengaging from the activity easier, new users, such as commuters, might want to set a lower tension than experienced racers.
Cleats frequently feature “float,” or the amount of lateral movement a heel can make by pivoting at the cleat, without the cleat unclipping from the pedal. As a result, each time the pedal turns, your foot can find its most comfortable position in relation to the pedal, hopefully preventing knee problems.
To enjoy the greatest comfort and efficiency, it is obviously crucial to align the cleats as precisely as possible when attaching them to your shoe.
Cleats recessed into sole
With the exception of a short-lived two-bolt road SPD pedal, the small, crucifix-style cleats on SPD pedals are designed to be worn on shoes with walkable soles. The majority of the time, this has a wide cut-out area around the cleat mount and is covered in grippy rubber tread. You can walk normally without worrying about slipping when the cleat is installed because it is recessed within the sole.
Walking is now a practical and secure option, and the cleat is shielded from needless harm. It is incredibly helpful for commuters and recreational cyclists who almost always need to include walking in their journey, and it makes any stops easier to deal with. Furthermore, SPD cleats are made of metal and, despite very heavy use, are generally very durable.
All-conditions durability
Since the weather isn’t always dry, SPD pedals are made to withstand mud and other obstacles that Mother Nature may throw our way. When you put your foot down, mud typically gathers around the recessed cleats, making it challenging to get the cleat back into the pedal. However, SPD pedals have spaces around and between most components, allowing mud to be pushed through and the cleat to engage.
This usefulness makes SPD pedals perfect for mountain bikes, cyclo-cross bikes, and gravel bikes, as well as for winter road cycling, where grippy footwear is appreciated due to the slick conditions underfoot and the likelihood of frequent stops.
Usually compact size
Due to their small size, they are less likely to collect too much mud than typical SPD pedals, which prevents them from reducing ground clearance during turns and corners. However, some riders prefer a wider, more grippy platform around the SPD mechanism, making it possible to use it whether you’re clipped in or not. This is particularly helpful in MTB gravity disciplines, commuting, and recreational cycling.
Why Use SPD-SL Pedals?
Bigger Pedal Platform
Low weight and power delivery are the two main focuses of the SPD-SL format.
The foot is held more firmly in place and there is a much larger platform with a wider pedal body and the noticeably larger interface between the pedal and the cleat on your shoe—ideal when sprinting.
For a secure connection to the shoe, the design makes use of a sizable plastic cleat and three widely spaced bolts on the bottom of the shoe.
However, walking in your shoes is uncomfortable due to the large cleat. You end up waddling, and if a surface is wet, you might slip. Furthermore, road cycling shoes have no grip on the bottoms other than a small pad at the toe and heel to lessen wear.
Although again they are not expensive, the cleats also tend to wear out more quickly than SPD ones and require more frequent replacement.
The deeper binding surfaces on SPD-SL pedals have a tendency to become clogged, which can make it difficult for your cleats to properly engage with the pedals if you do manage to step in any mud.
Therefore, SPD-SL pedal systems are made for riders who want to travel long distances on the road and who don’t anticipate having to put their foot down or move around a lot.
Single-sided Entry
Single-sided pedals are SPD-SL. Clipping in requires more precision than it does with SPD pedals because their natural resting position is obliquely downward. As a result, flipping the pedals over as you begin to ride is necessary to properly engage the cleat with the pedal’s top surface.
It takes practice to get it right, but once you do, it comes naturally.
Although tension can be changed to suit, some riders find that disengagement with SPD-SL cleats is a little more difficult than with SPD pedals. Beginners and commuters are also likely to prefer the double-sided SPD pedal design, especially when negotiating congested intersections and heavy traffic.
Other than that, SPD-SL pedals have the advantage of being lighter than SPD pedals at comparable prices, weighing typically between 50g and 100g less per pair. Premium SPD-SL pedals have carbon fiber bodies.
Adjustability
Like SPD pedals, SPD-SL pedals have an Allen key bolt in the back that can be tightened or loosened to change the release tension. A different cleat, distinguished by its color, can be used to change the amount of rotational float between the shoe and the pedal.
Shimano cleats come in a variety of colors, with yellow being the most popular. While the red-bodied cleats have no float for a fixed foot position, the blue cleats have no float for less lateral movement.
Similar to the SPD system, you can move your cleats around on the shoe to accommodate your preferred fit and pedaling style. The cleat’s angle can be adjusted, and most (but not all) shoes let you move the mounting plate inside the sole up and down.
What Are the Benefits of SPD-SL Pedals?
Larger pedalling platform
The most noticeable distinction between SPD and SPD-SL pedals and cleats is their relative sizes; triangular SPD-SL cleats are considerably larger than their SPD cousins. This increased size enhances efficiency by distributing power from your foot to the bike over a larger surface area.
Road-focussed use
The single-sided SPD-SL pedals, which are made specifically for use in road competitions, put their ultimate on-bike performance above all else at the expense of off-bike usability. The fact that their large plastic cleats extend from the sole at the ball of the foot makes walking more challenging.
In addition to being somewhat awkward to walk in and frequently prone to sliding on smooth surfaces, they are also quickly worn out by excessive walking, rendering them useless. Any foreign objects or mud can also have a significant impact on their connection. There are slip-on cleat covers that can be used to protect the cleats and provide traction when walking, but many riders find carrying them uncomfortable.
Pedalling and release options
Similar to SPD pedals, SPD-SL pedals typically come with cleats that provide a range of rotational “float” to allow each foot to find its natural position. Typically, Shimano pedals come with yellow-coded cleats that offer six degrees of float, as opposed to red and blue cleats that offer zero degrees and two degrees, respectively.
You can adjust how easy or difficult it will be to release your foot from SPD-SL pedals thanks to a tension release screw located inside the back plate.
Due to the fact that they are single-sided, you must always present your shoe and cleat to the appropriate side of the pedal. The front of the pedal is angled up to make it easier to find, while the bulkier rear always hangs down to help with this. Pushing forward causes the pedal to rotate until it touches the entire cleat. To do this, find the front of the cleat in the uppermost loop of the pedal body. After that, a forceful downward push should properly engage it.
Lightweight
The SPD-SL pedal’s low profile is made for aerodynamics, light weight, and maximum performance. Manufacturers look for opportunities to reduce weight wherever possible, and pedals are no exception. In the least expensive models, steel axles are used. Other materials include titanium, aluminum, or light carbon fiber for the pedal bodies. A pair of SPD-SL pedals are typically 50 to 100 grams lighter than their roughly equivalent SPD pedals in terms of price.
Other Options
Shimano pedals aren’t the only option; other brands also offer comparable two- and three-bolt systems. While others are not, some are compatible with Shimano pedals.
Shimano’s two-bolt pedal patents have since expired, making it possible for other manufacturers, like Look, to sell SPD-compatible pedals.
Crankbrothers, Wahoo/Speedplay, and Time are other significant manufacturers of two-bolt pedal systems, each of which has an incompatible system.
Shimano SPD-SL is not compatible with Look’s three-bolt pedals. Time’s road pedals are another road-going system with a three-bolt cleat design, but once more, there is no cross-compatibility with Shimano SPD-SL pedals.
Another significant player when it comes to road pedals is Speedplay, which is currently owned by Wahoo. In a metal cleat with four points of attachment to the shoe, the lollipop-shaped Wahoo Speedplay Zero pedals fit. In the cleat rather than the pedal, there is an adjustment mechanism.
To attach Speedplay cleats to three-bolt shoes, you can either use an adaptor, or you can buy shoes with four fixing points already built in to support Speedplay.
Conclusion: Should I Choose SPD Or SPD-SL?
Overall, SPD pedals are excellent for beginners using clipless pedals. For cyclocross or mountain biking adventures, it’s the ideal option thanks to its walkability and resistance to debris clogging.
The SPD-SL is the ideal option if you commute over long distances by road with little to no walking.