PM or IS, you know what you mean?
PM or IS, you know what you mean?
PM (post mount) and IS (international standard) are the different fixing systems for disc brakes on bicycles
Not all PM are exclusively prepared for a 160mm rotor, there are suspensions and frames on the market for direct application at 180 and 200mm.
What is the advantage of PM?
As the attachment is direct, there is not so much pressure and torsion in the suspension and frame, thus increasing braking efficiency.
The IS (international standard) that we still see very often, especially in the frames, is almost a must for a fixing adapter, except when the clamp itself is also an IS application as in the image below.
In this system, the brake calipers dictate the need for an adapter or not, but in large numbers, the brake calipers sold today are PM fixing.
But don't despair, if your bike is equipped with an IS system, there are adapters so you can use larger discs.
We hope to have helped you better understand these acronyms that make all the difference when we want to change the brakes and discs on our bike.
See you later.