This post compares the advantages and disadvantages of single-pivot and dual-pivot caliper brakes in relation to one another.
Before comparing the two types of brakes, it’s necessary to describe them.
Single Pivot Brakes. Single pivot brakes are caliper rim brakes with brake arms rotating around a shared pivot point. They’re found on old-school and modern entry-level road bikes.
When the user squeezes the lever, the brake cable pulls the ends of the brake arms which in return close and grab the rim.
Dual Pivot Brakes. As the name suggests, dual-pivot brakes are caliper brakes using two distinct pivot points for each arm. Fundamentally, the braking mechanism matches that of single-pivot brakes.
The Advantages of Dual-pivot Calipers
- Mechanical Advantage
The most essential feature of dual-pivot brakes is the extra leverage that the brake arm has.
There are two types of dual-pivot brakes – asymmetrical and symmetrical.
Asymmetrical dual-pivot brakes (image above) have one of the pivots at the center while the other is to the side. Symmetrical dual-pivot brakes have both pivots positioned to the sides.
The mechanical advantage comes from the increased distance between the pulled ends of the brake arms and the pivot point. The longer the distance, the greater the leverage becomes.
In the case of single-pivot brakes, the distance between the end pulled by the brake cable and the pivot point is equally short for both brake arms.
Asymmetrical dual-pivot brakes have one arm with a pivot point at the center (short distance) and another with a pivot point closer to the brake shoe (longer distance). The brake arm with the longer lever has a stronger mechanical advantage.
Symmetrical dual-pivots offer the greatest leverage because both arms are pivoting around a point closer to the brake shoe. The longer levers reduce the amount of force needed to grab the wheel.
Greater Stopping Power vs. Ease of Appliance
Many people say that dual-pivot brakes have greater stopping power, but that statement is not fully accurate.
The greater mechanical advantage provided by the additional pivot point and its location equal more stopping power for the same amount of force applied to the brake lever.
Or in other words, if the rider was to squeeze the brake lever with the same effort while using single-pivot brakes, the brake wouldn’t grab the rims as hard due to the lower leverage of the brake arms.
However, if the rider squeezes the brake levers harder, the single-pivot brakes could match the braking power of the dual-pivot unit.
Thus, some riders consider dual-pivot brakes more comfortable rather than more powerful.
This is backed by the observation that a high-quality single-pivot brake can outperform a low-quality dual-pivot model.
- Easier Centering
Centering is the process of ensuring that both brake shoes of a brake unit are at an equal distance from the rim. If the brake is off-center, one brake shoe will be hitting the rim before the other. The outcome is subpar braking and unequal wear of the pads.
Single-pivot brakes are more difficult to center for two reasons:
- Both brake arms stress the same pivot which serves as an attachment point to the frame or fork too.
2. There isn’t a centering screw. (In different, many dual-pivot brakes come with one. The centering screw makes brake centering fast and simple.)
If the brakes are of poor quality, the centering process is even more frustrating. But even if the brakes are high-end, they’re highly unlikely to remain perfectly centered for a very long time.
In the past, some mechanics were taking “drastic measures” to center a single-pivot brake such as placing a flathead screwdriver on the spring of the brake arm that has to go inward and then tapping the handle.
- Market Domination
Truth be told, single-pivot brakes have been losing market share ever since Shimano reinvented the dual-pivot brake.
At the moment, dual-pivot brakes dominate the caliper brake market. The competition results in the production of various models at a fairly affordable price.
The Disadvantages of Dual Pivot Brakes
- More Expensive
Dual-pivot brakes tend to cost more due to the more complex engineering and the extra parts that the mechanism needs.
That said, many brands such as Shimano and Dia Compe offer dual-pivot brakes at relatively low prices.
- Extra Weight
One of the main reasons why single-pivot brakes continue to be produced is weight.
Single-pivot brakes are simpler and have fewer elements. Consequently, they have the potential to be lighter.
However, the final weight depends on the model. In some cases, a dual-pivot brake is lighter than a single-pivot one.
The table below compares the weight of single-pivot and dual-pivot caliper brakes:
|Single Pivot||Weight||Dual Pivot||Weight|
|SRAM RED Brakes Aero Link||136g||Dia Compe MX806||210g|
|Dia-Compe BRS200||140g||XLC BR-R03||155g|
|Campagnolo Veloce D-Skeleton||174.5g||Campagnolo Record Dual Pivot Skeleton||158g|
|Shimano Dura-Ace B-210||189g||FSA K-Force WE||150g|
|Dura Ace BR-7400||191g||Dia Compe BRS202||200g|
|Shimano 600 BR-6400||180g||Shimano Dura Ace BR-R9200||163.5g|
Conclusion: Single-pivot brakes could offer about 50 grams of weight savings per wheel if we compare them to heavier dual-pivot models. However, there are also dual-pivot brakes that weigh as much or less than single-pivot units.
Therefore, one of single-pivot brakes’ advantages isn’t as substantial as people make it to be, especially if the rider is using modern dual-pivot brakes of decent quality.
Moreover, 100-120 grams do not affect the performance of a recreational rider and aren’t enough to outweigh the downsides that come with single-pivot brakes.
The Advantages Of Single-Pivot Brakes
The main advantage of SPC (single-pivot calipers) is that they have the potential to be lighter. But as already mentioned, the weight savings are inconsequential and sometimes not even present.
Single-pivot brakes require additional force and movement of the brake lever to “bite”. This property has a positive side too – the modulation of the brake is greater.
Or in simpler words, there are more “checkpoints” for the rider to choose from when braking.
Since single-pivot brakes are considered inferior technology, some models are relatively cheap.
- Retro Appearance
Single-pivot brakes come from the old-school era and complement the look of vintage bikes. Meanwhile, dual-pivot brakes appear modern and do not always blend when installed on a retro bike.
The Disadvantages of Single-Pivot Brakes
Single-pivot brakes are going extinct for two reasons:
a. Dual-pivot brakes are considered superior.
b. Disc brakes are gaining market share and keep pushing rim brakes towards slow retirement.
The low demand results in low supply and limited choice.
- More Finger Strength
The lower mechanical advantage of single-pivot brakes demands more finger flexion to stop. Consequently, it’s difficult to brake by using only two fingers, especially if the rider is a child or a female.
Conversely, the additional mechanical advantage provided by dual-pivot brakes facilitates two-finger braking.
- Lack of Innovation
Since single-pivot brakes are considered a thing of the past, companies are not investing in them. The rise of disc brakes isn’t helping either.
FAQ: Why do some bikes have a dual-pivot brake at the front and a single-pivot at the rear?
The goal of this practice is to get the advantages of both systems. The dual-pivot brake goes at the front to maximize the total braking power of the bike. (The front brake is more powerful thanks to the better-preserved friction of the front wheel during braking.)
The single-pivot brake is installed at the back to benefit from the additional modulation that it offers. Since the rear brake is used primarily for slowing down rather than stopping, some people consider the modulation of a single-pivot rear brake advantageous.
Of course, some riders hate using brakes with non-matching modulation.
Summary: What You Need To Know
- Dual-pivot brakes have a mechanical advantage making it easier to apply maximum braking force.
- Dual-pivot brakes are easier to center and keep their position for a long time.
- Dual-pivot brakes dominate the market.
- Single-pivots can be lighter since they require less material and fewer parts.
- Single-pivot brakes offer extra modulation which is why some people often use them as a rear brake.
- Single-pivot brakes often go off-center.
- Single-pivot brakes are going extinct due to the low demand.