from Rookie’s keyboard

Hello, fellas

Today, I am going to compare two types of brakes – U-brakes and the good old V-brake models. 

Let’s not waste any more time and get straight into it. (I will try to include as many bullet points as possible as I know that many of you are reading my posts on your phones during your commute.)

The Power of U-brakes

In a nutshell, the strong points of U-brakes are:

• Compactness

U-brakes are much slimmer than Vs and can fit on the underside of a BMX’s chainstays.

Why there? That placement protects the brakes during a crash and allows a streamlined cable routing under the downtube.

Hence the popularity of U-brakes in the BMX sector.

• “Gyro System Friendly”

Many BMXs come with a gyro system a.k.a. a detangler allowing the handlebars to make 360-degree spins without interference from the brake cables.

Without the magic of the gyro, the brake cables will make bar spin impossible.

To learn why U-brakes are gyro-friendly,  it’s necessary to have a basic understanding of a gyro’s mechanism.

The Mechanism of a BMX Gyro

Anatomy of a BMX Gyro

A gyro setup consists of:

Upper cables – the cables attaching to the brake levers and the top plate

A top plate – the plate that sits at the highest point of the gyro

A middle plate – the middle plate is the one that makes the magic happen. The top part connects to the upper cables and the top plate; the lower part is attached to the lower cables and the bottom plate.

The upper and lower part of the mid-plate have a bearing system between them. The upper part can rotate independently. (The lower part remains stationary.)

When the rider squeezes the brake, the upper cables pull the upper part of the middle plate which in return pulls the lower part of the middle plate and consequently the lower cables too.

Lower plate – the lower plate serves as a holding point for the lower cables. It remains stationary.

Lower cables – the low cables connect the gyro to the brake.

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Gyros use a dual brake cable so that the upper part of the mid-plate can pull the lower part of the mid-plate symmetrically and with sufficient force.

For that reason, U-brakes with a dual cable set-up make the installation of a gyro set-up easier and more streamlined.

A V-brake can technically be adjusted to work with a gyro too, but a lot more tinkering is needed since it isn’t a center-pull brake. 

There are also center-pull U-brakes that use a single pull cable combined with a straddle cable just like cantilever brakes. Those models are fully compatible with a gyro setup. The only difference is that the user has to connect the lower gyro cables to the straddle cable which then pulls both arms of the brake.

Cable Pull Differences 

Another property that makes V-brakes non-compatible with standard gyros is their cable pull. 

(The cable pull is the amount of cable that the brake lever has to pull for the brake to operate properly.)

V-brakes have a greater mechanical advantage and pull more cable. Conversely, U-brakes have a smaller mechanical advantage and require brake levers that pull less cable. 

For that very reason, V-brakes are called long pull brakes whereas U-brakes are short pull.

A V-brake lever needs to pull about 15mm for the brake to engage whereas a U-brake lever needs to pull only 7mm. For that reason, V-brakes and U-brakes need different levers.

The short pull of U-brakes makes them better for a gyro system because the mechanism doesn’t have to pull a lot of cable to initiate braking. 

A gyro system combined with a V-brake will result in poor braking unless there’s a converter such as Travel Agents allowing the use of a short pull lever with a long pull brake. 

In that case, however, the braking system will become incredibly complex due to the high number of involved mechanisms.

For the sake of simplicity, stick with U-brakes.

V-Brakes Are Still The King For Most People

The vast majority of people don’t care about “gyro systems” and BMX in general. If you are part of that group, you will be better off with V-brakes for the following reasons:

• Supreme Stopping Power

V-brakes have longer brake arms and a more advantageous pulling angle – qualities resulting in a greater mechanical advantage (leverage). In other words, V-brakes grab the rim harder for the same effort.

The additional stopping power is why V-brakes are the norm for race BMX bikes.

Since those BMX models aren’t used for freestyle stunts, the noodle and the cable sticking out on one side aren’t an issue.

• Availability

V-brakes are the most popular rim brake model. You can find them in every bike shop.

• Easier Setup

V-brakes are easier to install than center-pull brakes (cantilevers, u-brakes…etc.) due to the fewer settings that you have to play with.

But let’s be real…U-brakes are not complicated either. 

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The Disadvantages 

• Bulky

V-brakes are not as streamlined and come with a metal noodle that protrudes. If you hit the noodle while performing a trick, you may be frustrated.

V-brakes are difficult to install on the underside of a BMX’s chainstays due to the lack of real estate.

• Not ideal for a Gyro Setup

V-brakes are not designed for a gyro setup for the reasons presented above.

What would I choose?

I’ve tested both systems and prefer V-brakes without a shadow of a doubt. They are super powerful when set correctly, available everywhere, and compatible with a ton of bikes out there. 

And of course, they offer a lot more tire clearance – a plus when you want to install offroad tires. 

I would only run U-brakes on a BMX with a gyro system. Otherwise, I don’t see the point. They are harder to find, slightly trickier to install, and have smaller leverage. 

Of course, I also have to mention that the short pull of U-brakes makes them compatible with drop levers, but I don’t think this is a strong point. 

U-brakes are not more efficient than standard single or dual-pivot caliper brakes that come on most road bikes. And if you want more clearance, you can run cantilever brakes – those are compatible with drop levers too. 

Until next time, 

Rookie