Bicycles equipped with disc brakes have seen an explosive increase over the past year or two.
The most obvious difference when looking at a bike with disc brakes is the large plate attached to the side of the wheel.
It looks something like this.
This plate is called a "disc rotor."
If you just glance at them, these metal plates don't look all that different, but when you look closer, they actually vary quite a bit.
What are the differences, and how do they change things?
1. Rotor Size
(The diameter of the plate generally comes in four sizes: 140mm, 160mm, 180mm, and 203mm.)
This changes the braking power (larger rotors provide more stopping power).
2. Rotor Material/Shape
(There are many types, such as iron, stainless steel, and aluminum sandwiches.)
This affects not only braking power but also significantly changes the rate at which the rotor dissipates heat.
3. Mounting Method
So today, I would like to write about the mounting methods for these disc rotors.
First of all, the reason I chose to focus on this mounting method is that if you get this wrong, you'll trip up right from the start, so I figured it’s the best place to begin.
There are two main ways to mount a disc rotor.
The most common is the one that uses a "6-bolt rotor."
Disc brakes, which began being actively developed about 20 years ago, eventually settled on this shape for a time, making it the first standard mounting method.
Before this, there was a period where many standards existed, such as 3-bolt or 5-bolt patterns, and I still hear stories about hubs from that era that are still functional but can no longer be used because rotors are no longer available.
Then, some time after 6-bolt became the standard, Shimano finally introduced their long-awaited "Center Lock" system.
As you would expect from the world-leading Shimano, the convenience of this system, released later to the market, is excellent.
For starters, it uses only one-sixth the number of bolts compared to the 6-bolt system, allowing for quick installation and removal.
It is also lighter than the 6-bolt method, which I think is a significant advantage.
However, with advantages come disadvantages, of course.
6-bolt rotors can be used on Center Lock hubs if you use an adapter, but Center Lock rotors can never be used on 6-bolt hubs no matter what you do.
One disadvantage is this restriction of being "proprietary."
Furthermore, even though they are gradually increasing, the number of hub manufacturers that have adopted the "Center Lock" fixation method is still limited.
Manufacturers are limited to the likes of Chris King, White Industries, and DT Swiss, so there aren't many options for hubs.
(There might be others, but these are the ones we handle at our shop.)
So, if you ask "Which one is better!!,"
I personally think Center Lock is overwhelmingly better, provided you don't mind changing your wheels (due to a change in hubs). The reasons for this are the high quality of the rotors produced by Shimano and the rich variety of their rotors.
When it comes time to change your wheels, be sure to keep that in mind—it will only deepen your love for your bike.