Have you ever wondered why the disc brakes on your bike have holes in it? Means not like anyone in the manufacturing process went on a punching spree and just went on putting holes in the round metal block just like that, there has to be some reason and logic behind it after all. So we are going to check out the reason why these discs have holes in them or any other design for that matter really. We hope that you do know the exact mechanism as to how disc brakes work. If not, please refer to the article as to how they work so that you will be able understand this lot better. Now the exact reasons why the holes are put in the discs are as follows:
Cooling:
Yes, disc brakes when applied convert all the momentum into heat energy due to the frictional force because of which the discs heat up. Now if the discs heat up a lot more than they can handle, they will succumb under stress and result in a braking failure. This is the reason why there are holes in the discs to increase the surface area of the discs so that more area can come in contact with the discs to cool them. Had the discs been solid, they would have still been able to lose heat and yes, maybe the friction would have had been more as well and the braking would be stronger, but then the discs would heat up quickly and in no time the braking system would fail. The results could range all the way from disc reshaping to disc cracking or breaking due to the stress from the calipers on the vulnerable metal.
READ MORE: How Motorcycle Disc Brakes Work
Weight:
Yes, you might have a hard time to believe but the holes on the discs reduce as much as 300-500 grams off the bike’s weight. That actually might seem really less but translates into a lot when it comes to the performance of the machines. A single kilogram can make a huge difference, so 100 grams also does have an effect on everything. Plus considering that many litre class and other higher capacity bikes have dual discs on them, you can very well guess the amount of weight that must be saved off them.
READ MORE: Why Disc Brakes Are Better Than Drum Brakes?
Water Dissipation in Rains:
This is actually a much underrated reason but still an important one. Consider this, it is raining hard and your entire bike is wet including your brakes. Now if there are no holes on the disc, what would happen? There would be nothing to give the brake pads some edge to hold on it, the pads will get soaked up in water and the disc would remain all wet. When the brakes are applied the pads would simple connect with the disc and there would be no frictional force acting as there will be water lubricating the entire surface. Now just because there are holes, the brake pads are getting an edge there to hold on it, the edge of the holes scrape off the water from the pads and provide some frictional force to stop the bike. Yes the brakes will not be working at 100% efficiency, but it is still better than nothing, right?
Other than that there are many theories about it saying that it acts as a cleansing mechanism for the brake pads such that the holes edge clean up the pads, but it all sounds like hokum. But if anyone can prove it in any ways that would be great because at least when I checked, that was not the case here.Yes, disc brakes when applied convert all the momentum into heat energy due to the frictional force because of which the discs heat up. Now if the discs heat up a lot more than they can handle, they will succumb under stress and result in a braking failure. This is the reason why there are holes in the discs to increase the surface area of the discs so that more area can come in contact with the discs to cool them. Had the discs been solid, they would have still been able to lose heat and yes, maybe the friction would have had been more as well and the braking would be stronger, but then the discs would heat up quickly and in no time the braking system would fail. The results could range all the way from disc reshaping to disc cracking or breaking due to the stress from the calipers on the vulnerable metal.
READ MORE: How Motorcycle Disc Brakes Work
Weight:
Yes, you might have a hard time to believe but the holes on the discs reduce as much as 300-500 grams off the bike’s weight. That actually might seem really less but translates into a lot when it comes to the performance of the machines. A single kilogram can make a huge difference, so 100 grams also does have an effect on everything. Plus considering that many litre class and other higher capacity bikes have dual discs on them, you can very well guess the amount of weight that must be saved off them.
READ MORE: Why Disc Brakes Are Better Than Drum Brakes?
Water Dissipation in Rains:
This is actually a much underrated reason but still an important one. Consider this, it is raining hard and your entire bike is wet including your brakes. Now if there are no holes on the disc, what would happen? There would be nothing to give the brake pads some edge to hold on it, the pads will get soaked up in water and the disc would remain all wet. When the brakes are applied the pads would simple connect with the disc and there would be no frictional force acting as there will be water lubricating the entire surface. Now just because there are holes, the brake pads are getting an edge there to hold on it, the edge of the holes scrape off the water from the pads and provide some frictional force to stop the bike. Yes the brakes will not be working at 100% efficiency, but it is still better than nothing, right?
So this is why there are holes in the disc brakes. So next time if anyone is wondering as to why there are holes in the disc, you can tell him/her. But if they wonder about the mint with a hole, I am sorry; I am unable to help you about that. But jokes apart, it is a very important thing that disks have holes in this so that they can perform optimally at all times. There could be some other kinds of crevices and holes in the discs, not always round shaped, but then the function they all perform is exactly the same.
By: Pratik Patole