Condensed Answer: Caliper brakes can be converted to V-brakes only when the frame or fork have mounts for V-brakes or cantilever brakes.
If those mounts are not present, it will be necessary to replace the frame and/or fork or resort to less popular conversion methods.
Requirements to Convert From Caliper Brakes To V-brakes
The brake arms of V-brakes are secured to the frame or fork by two bolts threaded into special brake bosses.
If the frame is made of steel, the mounts are brazed to the frame or fork.
Brazing is a metal-joining process during which two pieces of metal are connected by melting a third metal (usually brass) over the connection point. The main advantage of brazing is that it doesn’t melt the base material (only the filler rod) and thus has lower chances of altering the integrity of the tubing.
If the frame is made of aluminum, however, brazing cannot be used because aluminum has a low melting point and thus can be damaged during the process. Instead, the mounts are TIG-welded.
In different, caliper brakes attach to the frame or fork via a single bolt passing through the fork’s crown or the seat stay bridge. Thus, a very big percentage of bikes originally designed for caliper brakes do not have the necessary mounts for V-brakes.
In that case, the user has the following options:
Get a New Fork
One of the options is to get a new fork with V-brake mounts. This isn’t a bad choice because most of the stopping power comes from the front brake.
During braking, there’s a weight shift to the front of the bike. As a result, the rear tire is partially unweighted. The reduced traction increases the chance of sliding when the wheel locks.
Conversely, the front wheel has extra traction during braking and thus much lower chances of sliding. Hence why people consider front brakes essential.
The new fork will have to meet the following criteria:
- Compatibility with the bike’s head tube
The new fork should be of the same type and thickness as the previous one. Otherwise, it will be difficult or even impossible to safely install it.
When it comes to the retention mechanism, there are two types of forks – threaded and threadless.
Threaded forks are secured to the head tube by a threaded cup part of the headset. Threadless forks do not have a threaded steerer and are secured by the bike’s stem instead.
Тhreaded forks are considered archaic and often come with a quill stem. Meanwhile, threadless forks are found on newer bikes.
While it’s technically possible to switch between threaded and threadless forks, the swap requires a great number of measurements to align. Thus, in most cases, it’s best to stick to the original type if possible.
The steerer is the part of the fork that passes through the head tube. The steerer of the new fork should match the thickness and shape of the old. If the steerer of the new fork is too thick, it may fail to pass through the head tube.
The length of the fork is important too.
If the fork is too short, it will lower the height of the handlebars. In some cases, it may even be impossible to secure the fork to the head tube.
Meanwhile, a fork that’s too long will elevate the handlebars and thus change the bike fit. For best results, it’s necessary to find a fork with a steerer close to the length of the original.
Axle To Crown Length (ATC)
The Axle to Crown (ATC) is the distance between the fork’s dropouts and the crown. The new and the old fork should have the same or extremely close ATC.
If the ATC of the new fork is shorter, the wheel of the bike may not fit. If the ATC is much longer, the head tube angle of the bike will get slacker and the handling will change.
Get a New Frame
A more radical approach would be to replace the bike frame with one that has V-brake mounts. This procedure is even more complicated than replacing the fork because it requires the user to re-install all bike parts on the new frame.
The new frame should meet the following criteria:
- Same size as the old one
- Compatible with the fork
- V-brake mounts
Braze or Weld V-brake Mounts to The Frame Or Fork
One of the most elegant solutions is to weld or braze a set of V-brake mounts on the frame or fork. However, this method requires a number of skills and equipment that most people don’t have. Thus, most users will have to pay a professional for that service.
The procedure will be more expensive when working with aluminum because the material requires advanced equipment. Also, aluminum loses strength due to the heat generated during welding and requires additional heat treatment. The final bill may exceed the price of a new fork or even a bike.
Clamp-On V-brake Mounts
Another option would be to install clamp-on V-brake mounts on the frame or fork. This method does not require welding and is very fast.
The downside is that clamp-on V-brake mounts are an exclusive product with low demand and are therefore more expensive than one might expect.
What Are The Advantages of V-brakes over Caliper Brakes?
- Tire Clearance
Calipers greatly limit the tire size that users can install. Conversely, V-brakes are an MTB invention and are therefore compatible with wide, balloon tires.
The extra clearance makes it possible to run full fenders too.
- Powerful Braking
V-brakes have more leverage than caliper brakes thanks to their extra length and more advantageous pulling angle.
As a result, quality V-brakes are comparable to a set of disc brakes when operating in dry conditions.
The different leverage of caliper brakes and V-brakes is why both brake types require levers pulling a dissimilar amount of cable.
Caliper brakes have smaller leverage and operate with brake levers pulling less cable. Otherwise, the wheel will be locked before the brake lever has completed its full travel.
Conversely, the extra leverage of V-brakes makes them long pull brakes. If they’re combined with short pull levers, the lever will reach its full travel before the brakes have grabbed the wheel.
The above will sound complicated to a beginner. To learn more about the effect of leverage on brake cable pull consider reading this article which explains it in greater detail.
Note: Mini V-brakes have smaller mechanical advantage than regular V-brakes and are therefore compatible with short pull levers.
Calipers are a road bike component. As such, the higher-end models tend to be expensive. Meanwhile, a decent set of V-brakes can be had for a reasonable sum.
- Compatible with Suspension Forks
A caliper brake is mounted to the fork crown whereas a V-brake goes on the fork’s legs. Consequently, it’s possible to use a V-brake with a suspension fork.
A caliper brake, however, cannot be combined with a suspension fork because it will move up and down along with the crown. As a result, the brake won’t be in line with the rim at all times.
Summary: What You Need to Know
To replace caliper brakes with V-brakes, you will need a frame and/or a fork with V-brake/Cantilever brakes bosses.
If the bike doesn’t have V-brake mounts, the options are:
- Get a new fork
- Get a new frame
- Weld or braze V-brake mounts
- Install clamp-on V-brake mounts
The advantages of V-brakes are:
- Large tire clearance
- Powerful braking
- Compatible with suspension forks
- High-end units at an affordable price