Re: Hero Honda Karizma ZMR

After removing the snorkel, take the bike out for a spin. Only then you'll come to know the difference. While idling, you cannot make out any difference.

Re: Hero Honda Karizma ZMR

Kari gets ready for the much needed pampering. Got the OE sticker set from safex bikes dot com.

I plan on carrying the job in a month as I find time.



Currently, she looks like this.

Re: Hero Honda Karizma ZMR

After a long wait got hold of Petal Disc from Honda Hornet [emoji1]

Re: Hero Honda Karizma ZMR

Does the petal disc work better?

Re: Hero Honda Karizma ZMR

A tad bit better.

Re: Hero Honda Karizma ZMR

The petals. How do they help better?
Is it that they get more cooler or that there is a discrepancy in the level of contact to the break pads that result in improved braking?

Re: Hero Honda Karizma ZMR

They cool better. Contact patch rrmains same.

Re: Hero Honda Karizma ZMR

For me the difference is drastic because my old rotor was at it's end of life.

Re: Hero Honda Karizma ZMR

Well i am not sure if they cool better . My view :

More the surface more will be the heat transfer, thats the difference between a bowl and a pan .
The design of disc was inherently round , now manufacturer cuts material along the circumference to "reduce weight"
While this does give benefit , but question arises by how much and by what magnitude ?

If you see the best disc setups are considered to be solid/plain discs as found in cars.
You might ask then why do motorcycle brakes are drilled or have petal shapes

One reason : Aesthetics .

Well the drilled rotor serves as vent holes for water layer that forms over the rotor , effectively breaking the surface tension created by water.
Since motorbike wheels are exposed to much more water and grime , drilled rotors helps. Petal shape reduces the disc mass , hence reducing the unsprung mass which in return lowers the gyroscopic effect of the wheel. but again the benefit is not groundbreaking or even felt .

Look at F1 cars or rally cars, they use solid rotors or at max slotted rotors, Drilled rotors are fad for cars.

If anyone whats to counter state this , please feel free

Re: Hero Honda Karizma ZMR


Perfect explanation.. now back to Square 1.. Is it good enough to go for the pedal rotor over the stock round rotor?

Edit: enuf to enough..

Re: Hero Honda Karizma ZMR

Please get an infrared heat sensing gun from Amazon. I knew I may have to explain this to someone some day.
After a city choc a bloc ride, my stock rotor showed a temperature of 99-102 degrees. When touring, this figure went higher, during the course of a day. 107 if I remember correctly.
I have not toured for more than 300 km one way with the new set up yet, but the temperature gauze showed only 86 degrees.
So yes, it is running cooler.
Another explanation is less brake fade when the rotor gets hot.

Aesthetics is NOT the sole reason. Tata Prima racing uses drum brakes with water aided cooling, so should we assume that discs are a fad altogether?
Naah man, we expect better responses from you.

Yes, it costs half as much and provides a better feedback. But then you're rich anyways. You may stay stock!

Re: Hero Honda Karizma ZMR

I will go for the Pedal rotors in that case.. thanks for the suggestion

Re: Hero Honda Karizma ZMR

Its Petal , because of the shape . Upon normal disc benefits wont be much , as the weight reduced will be at max 100gms or say 200 at most.
For a front wheel assy that weighs 2-3kg atleast , will a 200gm removal be noticed ?. As far i know , it wont be.
So why does OE opt for a petal brake and why does customer perceive it to be better than stocks ?
The truth lies in the operating pressure of the disc assembly and the pad quality.

But i am not saying that petal discs are just a gimmick, no not at all.
They reduce the angular mass hence the inertia of the disc
Lower the inertia , lower the force required to move or stop it.

but the difference in mass of the disc is what the governing parameter is. In this case the difference is not a huge amount so, perceived benefit would be less too.

Re: Hero Honda Karizma ZMR

P.S - Hornet's rotor is heavier than ZMR's OE rotor.

Re: Hero Honda Karizma ZMR

BTW car discs ARE ventilated. Two solid discs bridged for ventilation.

Sent from my XT1033 using xBhp Connect mobile app