Ultra-detailed Comparison: V-Brakes vs. Mechanical Disc Brakes (free bike theory lesson)

This post compares the advantages and disadvantages of V-brakes and mechanical disc brakes in relation to one another.

The Advantages of Disc Brakes

V-brakes are often seen on commuter bikes.
  • Lower Cost

V-brakes are older and simpler technology. It’s possible to buy high-end models for a lot less than it costs to acquire a set of disc brakes from the same class.

This property makes V-brakes a good choice for budget builds and beater bikes.

  • Good Stopping Power In Dry Conditions

A decent set of adequately adjusted V-brakes offers a lot of stopping power in dry conditions. The level of effectiveness is comparable to that of disc brakes.

  • Simplicity

V-brakes are not extremely complicated. When the rider presses the lever, a cable squeezes the two brake arms together. The arms pivot around the brake bosses and the brake pads grab the rim.

Unlike disc brakes, V-brakes do not require a brake rotor and have visible brake shoes making calibration easier.

Most of the adjustments needed to properly calibrate a V-brake are done with an Allen key.

  • Interchangeable Replacement Parts

V-brakes follow the same schema across brands and allow the user to easily find replacement parts and brake shoes even when traveling to remote destinations.

In different, disc brakes are often brand and model specific. Consequently, it’s not always easy to find replacement parts and brake pads.

  • No Rear Rack Interference

Many bikes equipped with disc brakes cannot accept standard rear racks because the caliper of the rear brake gets in the way of the support legs.

As a result, the user has to purchase disc-brake-specific rear racks. And while those models work well, the choices are limited and sometimes the price tags are higher than needed.

In different, V-brakes do not create this issue because the body of the brake is far away from the support legs. Thus, the user can choose between a greater variety of rear racks.

  • Lighter

V-brakes consist of two brake arms and do not require a brake rotor because the rim serves as one. As a result, V-brakes tend to be lighter than disc brakes.

That said, the rim has to be thicker and thus heavier due to the brake track that the brakes are grabbing. If the brake track is slim, the rim will wear down too fast.

The table below compares the weight of V-brakes and mechanical disc brakes.

V-brakesWeightMech. Disc BrakesWeight
Shimano Deore XT BL-T780-B196.6gSRAM BB7170g
Shimano Deore XT BL-T780-B174gAvid BB5215g
Shimano Deore BR-T610168gTRP Spyre SLC146g (road)
Shimano Alivio BR-T4000188gHayes CX5195g (road)
Tektro M530158gShimano BR-R317183g
Tektro M730158gShimano BR-RS305170g

The data shows that the weight difference between V-brakes and mechanical disc brakes is small.

However, the mechanical disc brake column shows only the weight of the caliper without the caliper. The rotor itself easily adds 100 grams to the whole set-up.

Thus, in some cases, a V-brake can save close to 200 grams per wheel or 400 grams in total. In the world of cycling, this is considered a lot.

Note: The pads of V-brakes affect the weight of the brake too. There are lightweight models making the brake even lighter.

The Disadvantages of V-Brakes

  • Lower Braking Power In Wet Conditions

The main downside of V-brakes is the reduced braking power in wet and dirty conditions.

The rim has a large surface that’s very close to the ground and in contact with the tire. As a result, the rim gets wet and contaminated. When the brake shoes grab the rim, the first few spins of the wheel clean the wheel and only then full braking power is reached.

For that reason, V-brakes are considered sub-optimal for riding in the rain and off-road. Hence why disc brakes are the norm for modern mountain bikes.

That said, V-brakes are still adequate for commuting and recreational riding.

  • The Wheel Must Be True

The pads of V-brakes have to be close to the rim for the rider to quickly initiate braking. If the rim is not true (round) and has deviations to the right or left, one brake shoe will touch the rim before the other. The contact will happen at the deformed location.

As a result, there will be noticeable rubbing, and the brakes will “catch and release”. The affected wheel (usually the rear) will “stutter”.

To avoid this experience, the rider may spread the brake arms further apart. This action will prevent rubbing between the deformed rim side and the respective brake shoe when the brake isn’t used, but it will not prevent stuttering of the wheel during braking.

Also, moving the brake arms further away slows down the application of braking force and reduces its intensity.

In short, rim brakes require true wheels for optimal performance.

via: pixabay.com

On the other hand, disc brakes grab a rotor connected to the wheel’s hub rather than the rim. Thus, the rim can be notably out of true, and yet the brake would still work as intended. That said, the rotor itself may get bent and create rubbing.

This scenario is a bit less common, although very real, hence the existence of special tools to straighten the rotor.

Rotor truing tool

Ultimately, it’s a lot easier to re-align or replace a rotor than it is to true a rim or change it. The second process requires more skills, time and equipment (spoke wrenches, truing stand…etc.)

  • The Rim is a Consumable

Sooner or later, the brake shoes will wear down the brake track of the rim. When that happens the rim should be immediately replaced. If it’s not, the wheel may collapse unexpectedly.

Ultimately, V-brakes, as well as other rim brakes, make rims a consumable.

  • Limiting Tire Clearance & Mud Accumulation

V-brakes encompass the wheel and thus limit the size of the tire. Usually, this isn’t a major problem because there’s plenty of space to install a wide wheel.

Another shortcoming is the possibility of mud accumulation around the brake. In extreme cases, the clogged area may even prevent the wheel from spinning.

In different, disc brakes do not limit tire width nor create an opportunity for mud accumulation.

  • Heavier Non-Aero Rims

V-brakes require rims with a brake track. The brake track is a thick, flat part of the rim that the brake shoes grab and rub against. The brake track adds weight to the rim and reduces its aerodynamic properties by a slight margin.

In different, disc rims can be lighter and more aero because they don’t need to have a brake track.

The Advantages of Mechanical Disc Brakes Over V-Brakes

  • Consistent Stopping Power Even In Suboptimal Conditions

The main advantage of disc brakes is their consistent stopping power even in wet and dirty conditions.

The brake rotor is small compared to the rim and positioned further away from the tire and the ground. Thanks to its position, it isn’t affected as much by water and dirt.

Additionally, the rotor provides a larger contact area for the pads than the brake track of a rim.

That doesn’t mean that braking doesn’t suffer in wet conditions, but the downgrade is much smaller, especially when using disc brakes of higher quality.

If the bike in question is going to be used off-road and in all weather, disc brakes are a logical choice over V-brakes.

Note: It’s recommended to stay away from no-name entry-level disc brakes because they tend to perform poorly even though the fundamental technology is superior to that of V-brakes.

  • No Need For Perfectly True Wheels

As mentioned earlier, a disc brake will continue to operate even when the rim is out of the true as long as the rotor is straight.

Since the rotor isn’t subjected to impact during riding (unless there’s a fall), it’s a lot less likely to get bent. This makes disc brakes less dependent on the rim.

  • The Rim Is Not a Consumable

Unlike V-brakes, disc brakes do not wear down the rim. Only the rotor and the brake pads need replacement.

Consequently, the rider can use the same rim for as long as it’s intact. This provides a greater incentive to invest in a set of high-end rims.

The Downsides of Mechanical Disc Brakes In Comparison To V-Brakes

  • Extra Weight

The rotor and the caliper body add weight to the overall setup. Thus, if the goal is to acquire the lightest possible bicycle rim brakes help.

That said, the weight savings aren’t fundamental, and the average user will not perceive them.

  • Extra Cost

Disc brakes are more complex and thus tend to cost more. Nonetheless, mechanical disc brakes are on the cheaper side and a quality set can be acquired for a reasonable sum. I’ve used entry-level Shimano mechanical disc brakes for years. They work just fine for my needs.

  • Interference With Rear Racks

In some cases, the body of the brake caliper will prevent the installation of a standard rear rack. Whether this will happen depends on the frame’s architecture. When I was using a rear rack on my hardtail, I had to purchase a special one with L-shaped support legs.

via: pixabay.com

FAQ: Do V-brakes and mechanical disc brakes use the same levers?

V-brakes and MTB mechanical disc brakes use the same levers. However, V-brakes cannot be used with road disc brakes. For more information, consider reading the dedicated post.

FAQ: Can I upgrade from V-brakes to disc brakes in the future?

V-brakes and disc brakes use completely different mounts. In many cases, frames and forks designed for one type do not support the other. That said, some forks have mounts for both disc and V-brake models.

If you want to upgrade to mechanical or disc brakes in the future, make sure that the fork and frame have disc brake mounts. Otherwise, an upgrade will not be possible.

Who Are V-brakes For?

V-brakes are a logical choice in the following situations:

  • When building a budget build/beater bike
  • When the bicycle in question is not used in extreme conditions
  • When the bike should be as light as possible while still having wider tires

Who Are Mechanical Disc Brakes For?

Mechanical disc brakes are a logical choice in the following situations:

  • The user wants a brake that loses minimal power in wet conditions but doesn’t want to spend extra on hydraulic disc brakes.
  • The user doesn’t want to replace the rims of the wheels unless it’s absolutely necessary.
  • The user wants to ensure an upgrade path to hydraulic disc brakes in the future.
  • The user doesn’t care about having the lightest possible bicycle.

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