Rear hat material - cast iron vs aluminum

[BULL]

@sad

Regarding the discussion over *there*, what were your thoughts about the rear hat?

We are moving forward with an aluminum hat (with integrated parking brake drum).

I'd love to hear your thoughts on it either way.

Personally, I was initially against it, but then after living with them from another manufacturer, I've come to understand, and accept, the approach of using it.

Others are welcome to join as well.

@TrackDay
@DGatzby
@Speedy!

Or anyone else.

 

[Speedy!]

I ran Baer brakes on the old car ($$$$) and the rear had an aluminum hat with integrated park brake drum. Never had an issue. What's the discussion point I don't go to the old site anymore.

 

[sad]

I’ve had no issues at all with mine. Been on the car 3 years.

 

[BULL]

I ran Baer brakes on the old car ($$$$) and the rear had an aluminum hat with integrated park brake drum. Never had an issue. What's the discussion point I don't go to the old site anymore.

It seems that RacingBrake believes that a parking brake drum with an aluminum surface is not only unsafe, but also "illegal".

There's a rather lengthy response from the President of Girodisk that basically says that he is wrong and "get bent" (my words).

I’ve had no issues at all with mine. Been on the car 3 years.

Sorry, I guess I misinterpreted your response over there.



The reason that I brought it up over here is what I mentioned above in my post.

When I first saw the aluminum rear hat, my gut reaction was that it wasn't right. While the idea of an aluminum hub in and of itself did not bother me, I was mildly concerned about the idea of the parking brake shoes on it. In short, I went with the DP/Girodisk setup and tried it. The long and short of it is that I no longer have any issues with the idea.

I don't drive around with my Parking brake set, and I don't have a belief that the Parking brake is going to save me in an emergency. IF I ever do have the foresight and circumstance to use my Parking brake in an emergency, I'm ok with the potential need to have to replace the rear hat sections as needed, if needed. I honestly believe that if that ever did happen, it's going to be as I'm pulling away from the garage at a couple of mph when I realize my brakes are out and I'll use the Parking brake to stop the vehicle.

If I have an issue on the highway at speed, a panic stop with the Parking brake is going to result in a loss of control and likely a crash anyway. If I have time for a controlled stop by modulating the Parking brake, I'll be happy to replace the hats.

For me, it's really that simple. But I also wanted to have the conversation because it's where CDT is going (has gone).

And just to head off any confusion, the aluminum alloy we are using for our hats and the aluminum-MMC we are using for our disks are not the same thing. As such, the ideas and concepts related to this discussion do not transfer to the primary brakes.

 

[06SRT10NR]

ditto on the DP/Girodisk. I may be the only one here who's worn down a set of rings on them, replaced them 5 months ago [front was too thin for my comfort, swapped out the rears as well]. Noticed no deformation in the hats, or other damage, so a ring swap was all that was needed, after ~27000 miles, a few track days at CMP, and numerous 1/8 and 1/4 miles, and all the hard braking that goes with them [plus a couple deer induced "panic stops" with the ABS disabled].

 

[BULL]

ditto on the DP/Girodisk. I may be the only one here who's worn down a set of rings on them, replaced them 5 months ago [front was too thin for my comfort, swapped out the rears as well]. Noticed no deformation in the hats, or other damage, so a ring swap was all that was needed, after ~27000 miles, a few track days at CMP, and numerous 1/8 and 1/4 miles, and all the hard braking that goes with them [plus a couple deer induced "panic stops" with the ABS disabled].

I think they are a decent rotor (for cast-iron). I did crack one after only 500 miles, but DP was fantastic about replacing it without question. Others didn't fair quite as well.

When you replaced them, did you have any undue cracking? (Yes, I guess I'm derailing my own thread...)

 

[06SRT10NR]

I think they are a decent rotor (for cast-iron). I did crack one after only 500 miles, but DP was fantastic about replacing it without question. Others didn't fair quite as well.

When you replaced them, did you have any undue cracking? (Yes, I guess I'm derailing my own thread...)

I seem to recall there we a few 1/8:-3/16" maybe hairline cracks that had started on the inner edge. If I remember right two or three were along points where the hat hardware was attached. more on the fronts than the rears. Didn't save them, went into the recycle bin, so can't give you any pics

Edit: none, as far as I could tell, went through the disk

Another edit: I was more concerned about the lack of safety wire on the inside of the mounting points

 

[BULL]

I seem to recall there we a few 1/8:-3/16" maybe hairline cracks that had started on the inner edge. If I remember right two or three were along points where the hat hardware was attached. more on the fronts than the rears. Didn't save them, went into the recycle bin, so can't give you any pics

Edit: none, as far as I could tell, went through the disk

Another edit: I was more concerned about the lack of safety wire on the inside of the mounting points

Safety wire

Interesting

Let me ponder that

 

[sad]

It seems that RacingBrake believes that a parking brake drum with an aluminum surface is not only unsafe, but also "illegal".

There's a rather lengthy response from the President of Girodisk that basically says that he is wrong and "get bent" (my words).





Sorry, I guess I misinterpreted your response over there.



The reason that I brought it up over here is what I mentioned above in my post.

When I first saw the aluminum rear hat, my gut reaction was that it wasn't right. While the idea of an aluminum hub in and of itself did not bother me, I was mildly concerned about the idea of the parking brake shoes on it. In short, I went with the DP/Girodisk setup and tried it. The long and short of it is that I no longer have any issues with the idea.

I don't drive around with my Parking brake set, and I don't have a belief that the Parking brake is going to save me in an emergency. IF I ever do have the foresight and circumstance to use my Parking brake in an emergency, I'm ok with the potential need to have to replace the rear hat sections as needed, if needed. I honestly believe that if that ever did happen, it's going to be as I'm pulling away from the garage at a couple of mph when I realize my brakes are out and I'll use the Parking brake to stop the vehicle.

If I have an issue on the highway at speed, a panic stop with the Parking brake is going to result in a loss of control and likely a crash anyway. If I have time for a controlled stop by modulating the Parking brake, I'll be happy to replace the hats.

For me, it's really that simple. But I also wanted to have the conversation because it's where CDT is going (has gone).

And just to head off any confusion, the aluminum alloy we are using for our hats and the aluminum-MMC we are using for our disks are not the same thing. As such, the ideas and concepts related to this discussion do not transfer to the primary brakes.

Sorry. I did have a problem with 1 hat. The rotor/hat ended up with a tiny bit of play causing noise and vibration. I replaced and torqued new hardware.... no improvement. So that meant the problem was either the ring or the hat itself. Replaced hat and problem went away. So it seems the holes for the hat wallowed out a micron-ish.

So my "no problem" comment was referring to the rear and braking assembly. No issues related to the e-brake or hat due to using aluminum as the material.

As for the front. I suspect something in the attachment hardware came loose. Hardware could have backed out. Tiny vibration caused it to wallow. Not sure if defect, or simply an unlucky situation.

No other problems of any kind.

 

[Hpindy]

I have a set of demon performance rear rotors on my car and I believe they have an aluminum hat . I put 20,000 miles on them so far .

Sent from my BBF100-2 using Tapatalk

 

[Speedy!]

May be of interest, maybe not, but relevant none the less.

http://www.speedysgarage.net/challe...lenger_baer_brakes/challenger_baer_brakes.htm

 

[06SRT10NR]

Safety wire

Interesting

Let me ponder that

just a little something for peace of mind ... and to ensure hardware doesn't back out, not that that happened, or will

and yes, I know my skill at drawing on a trackpad is somewhere below crap

 

[BULL]

just a little something for peace of mind ... and to ensure hardware doesn't back out, not that that happened, or will
View attachment 37757
and yes, I know my skill at drawing on a trackpad is somewhere below crap

I've done more safety-wire than God.



(see avatar)

 

[McLovin]

It seems that RacingBrake believes that a parking brake drum with an aluminum surface is not only unsafe, but also "illegal".

There's a rather lengthy response from the President of Girodisk that basically says that he is wrong and "get bent" (my words).





Sorry, I guess I misinterpreted your response over there.



The reason that I brought it up over here is what I mentioned above in my post.

When I first saw the aluminum rear hat, my gut reaction was that it wasn't right. While the idea of an aluminum hub in and of itself did not bother me, I was mildly concerned about the idea of the parking brake shoes on it. In short, I went with the DP/Girodisk setup and tried it. The long and short of it is that I no longer have any issues with the idea.

I don't drive around with my Parking brake set, and I don't have a belief that the Parking brake is going to save me in an emergency. IF I ever do have the foresight and circumstance to use my Parking brake in an emergency, I'm ok with the potential need to have to replace the rear hat sections as needed, if needed. I honestly believe that if that ever did happen, it's going to be as I'm pulling away from the garage at a couple of mph when I realize my brakes are out and I'll use the Parking brake to stop the vehicle.

If I have an issue on the highway at speed, a panic stop with the Parking brake is going to result in a loss of control and likely a crash anyway. If I have time for a controlled stop by modulating the Parking brake, I'll be happy to replace the hats.

For me, it's really that simple. But I also wanted to have the conversation because it's where CDT is going (has gone).

And just to head off any confusion, the aluminum alloy we are using for our hats and the aluminum-MMC we are using for our disks are not the same thing. As such, the ideas and concepts related to this discussion do not transfer to the primary brakes.

I was wondering what the plan was for the rear, but figured that would be answered in due time.

So 2 piece I assume?

 

[BULL]

We've got the initial rear (2-piece) design done, using D-bobbins at the interface.

The mentality is that while we will still do dyno testing on the rear, with the higher energies of the front, that's where we are going to focus our efforts.

(If our design survives ~100k watts up front, it will survive ~70k watts in the rear)

 

[BULL]

(We're using the O.E. H-bobbins up front)

 

[DGatzby]

You want my input? WTF is a parking brake? Never use one. Make them as light as you can. Keep going. He may have some okay products, but I value relationships. So I’ll wait for a few months.

Speaking of DP, the most used set of rotors I have, show the worst heat cracks I have ever seen. Both DP and GD were entirely non-responsive to my requests for help when I asked. I have another set of barely used rotors. I’ll be using them this year, then done. Your up @BULL !

You need to get those things done! Later this season is about right.

 

[DGatzby]

One more thing, the retailer, DP or GD would not sell me a spare set of hardware either. Fine! I know a new smaller company will have superior customer service if needed. Good luck guys, make it happen.

 

[BULL]

You want my input? WTF is a parking brake? Never use one. Make them as light as you can. Keep going. He may have some okay products, but I value relationships. So I’ll wait for a few months.

Speaking of DP, the most used set of rotors I have, show the worst heat cracks I have ever seen. Both DP and GD were entirely non-responsive to my requests for help when I asked. I have another set of barely used rotors. I’ll be using them this year, then done. Your up @BULL !

You need to get those things done! Later this season is about right.

Getting ready for my dyno trip tomorrow, we leave in the morning.

The threshold moments are going to be Tuesday morning and then Wednesday morning.

I'm either going to come home on a cloud, or with shattered teeth from gritting them.

 

[SIXGUN]

I've recently installed Dba rings up front and two piece DP rotors out back and have Hawk 70s for the track. First trip to Sebring with them will be in a couple weeks. Time will tell.
Mfgrs now call it a Parking brake. Have only used mine a time or two in 11.5k miles. If I need it in an emergency, I'm sure an aluminum drum will get me stopped, if only once. I'll take a look after and let you know. (I haven't had to use an emergency brake yet except for J-turns...and not in this car!)