http://www.thebrakeman.com/mazda

What do you guys think of the wavy brake rotors? Very interesting if you asked me. Any opinions about this rotor/braking system? (jimlab, maxcooper, etc...feel free to respond)

 

I believe you have to buy these rims to get adequate clearance for that brake kit...



Seriously, it's just a different shape. It might be lighter than a traditional circular rotor, but on the other hand, it might not shed heat as well as a rotor with additional mass, either. Personally, I'd say it looks like a waste of money. It doesn't appear that they have anything more than stock-size replacements for the FD.

http://www.thebrakeman.com/rx7

 

I thought about the ability for the rotors to shed heat as well, but I wasn't sure so I figured I would ask the "experts" of this forum.

I haven't seen those Ronal Bear rims in a long time! I've only seen them once in person...hahahahahhaa.

 

If you don't like the bears, you can go with these instead...

 

There are a couple things that affect braking ability:

Swept Area (the area the brake pads contact on the rotor faces)

Cooling Efficiency (cross drilled, vented, mass of the rotors themselves)

Out Gassing removal (slotted rotors)

Pad/Rotor Material

The swept area is where the friction energy (?) is changed into heat energy. The larger this overall surface area, the more efficient the brakes (hence larger rotors tend to stop better). I don't see how these wavy rotors would increase the swept area using stock pads, since the stock pads are already touching 100% of what they can. So no gain there.

Cooling efficiency doesn't appear to be increased either. There is no cross drilling, the rotors are vented (but so are stock ones), and there actually seems to be less rotor mass in the wavy ones. Assume for a second that the stock rotors have very minimal diametrical clearance with the caliper. Then, with these rotors, one must assume that the outer most portion of the wave (largest diameter) will have the same clearance. This means the inner diameter areas will have a bigger clearance and since the caliper is still the same distance from center, the area (and subsequent mass) of the brake rotor is reduced (notice this also reduces the swept area). This is not good.

The outgassing ability is increase here, but not because of the shape of the rotors. The conventional slots help to do this.

Assuming that the rotor material is the same as stock, or at least has the same friction coefficient, there is no gain here either.

In my opinion, these are a gimick. If wavy rotors really worked better than circular, then they'd be on race cars by now, don't you think?

 

This is becoming a popular mod with sportbikes. If you're too poor to upgrade to cast iron disks and radial mount Brembos, then I guess the wave rotors with better brake pads are the next best thing. Honestly, the reason why they're used on sportbikes is because is lower rotational inertia and provides less gyroscopic effect (easier steering). I don't see much use on a car however.
Michel

 

Yeah, I don't see how the wavy rotors would help braking. They do have more surface area per unit mass for better cooling, but it seems like any benefit there would be offset by the loss of mass. The reduced rotational inertia would help braking, too, but that advantage is surely more than offset by the loss of mass (two sides of the same coin).

I'd be afraid of a rock or something getting tangled up between the caliper and the rotor, too.

-Max

 

The more interesting product at the brakeman site is the "hurricane rotor" made of laminated steel with extra cooling fins sticking out of the vanes. Really freakin' expensive though, and I haven't seen any reviews from anyone that's used them...

 

Where are the wavy brake pads? haha