Now that you have confirmed in our previous [PIT TIPS] Disc Brake Primer Vol. 2 - Preparation for Disc Brake Installation that disc brakes can be fitted to your bike and you have decided between a "cable-actuated" or "hydraulic" system, it is time to choose your levers and calipers.
Things to keep in mind when choosing: first, regarding calipers and levers for "hydraulic" systems.
For "hydraulic" systems, compatibility between the caliper and lever is crucial.
Unless you have a very specific setup, you should stick to the same manufacturer and model for both the lever and the caliper.
You can essentially assume that there is no compatibility across different manufacturers.
When using hydraulic brakes with drop bars in particular, they are integrated with the gear shifters, so you also need to pay attention to the manufacturer, model, and the number of speeds.
Next, points to consider when choosing a "cable-actuated" system.
When installing or switching to "cable-actuated" disc brakes on your current bike, you will often continue using your existing brake levers. In such cases, there is one especially important point to note.
That is the "cable pull ratio" of the lever you are using. Be aware that this varies depending on the lever.
While you could get into technical details, for bicycles, it is enough to remember the difference between two types.
They are "long pull" and "short pull."
Another way to refer to them is "V-brake ratio" and "cantilever brake ratio," but they mean the same thing, so you only need to remember one set of terms.
These two are also important when choosing standard rim brakes, but please be aware that they are absolutely not compatible with each other.
If you mix them up, it will significantly impair your control and could cause serious accidents due to brakes that are either too sensitive or not responsive enough, so please exercise extreme caution.
If you are unsure of your brake's cable pull ratio, the best course of action is to check the model name on the manufacturer's website or ask a shop staff member.
Let's look at the PAUL COMPONENT Klamper caliper as an example to see how they differ.
The yellow lines indicate the parts where the cable pull ratio differs.
First, from the front.
Next, from the side.
The cable pull ratio is adjusted by changing the length of the lever arm that holds the cable and actuates the internal piston. It is easy to see the difference if you have them side-by-side, but it is difficult to identify on its own, so please make sure to confirm before purchasing.
Now that you have identified the cable pull ratio, it is time to choose your calipers.
Regardless of whether they are "cable-actuated" or "hydraulic," calipers have two ways of moving the pads.
These are "dual-piston" and "single-piston."
This refers to whether the pistons that move the pads to contact the rotor and create braking force move "on both sides" or "only on one side" when the lever is pulled.
They move as follows:
Dual-piston
Single-piston
The pros and cons of each are:
Dual-piston: The pistons move in parallel, providing a better braking feel.
The structure is more complex, making them prone to being heavier and more expensive.
Single-piston: The structure is simple, making them more durable and lightweight.
Since only one pad moves, the pad wear is not uniform.
While these are their basic characteristics, you rarely see single-piston designs in "hydraulic" brakes these days, and you won't see dual-piston designs in "cable-actuated" brakes other than from TRP, so it is generally safe to assume that "hydraulic = dual-piston" and "cable-actuated ≈ single-piston."
Now you have all the criteria needed to select your calipers and levers. There are many manufacturers and models, so enjoy the selection process!
If you are unsure, please feel free to ask us for advice at any time.
There is not much left in our long-running disc brake primer. Let's keep at it for just a little longer!!
Related Disc Brake Articles
[PIT TIPS] About those plates on wheels you often see lately – Disc Rotors –
[PIT TIPS] Disc Brake Primer Vol. 1 – The Dos and Don'ts of Disc Brakes –
[PIT TIPS] Disc Brake Primer Vol. 2 – Preparation for Disc Brake Installation –