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View Full Version : Anyone for brake rotor disc cussion ?



Jasper
03-12-2006, 08:50 AM
I've researched it quite a bit and would like any opinions on replacing my front rotors. I have a '01 ST4 with about 14,000 miles on 'er, bought used so I don't know the history. I've got the infamous brake shutter when clamping
on the binders, only noticable when you need brakes the most.

I checked the thickness and they are under specs for thickness, being thinner towards the center but even the outer edge is only 3.4mm on one disc (3.6 is the minimum).

I don't ride the track and don't get too wild and crazy so
I wonder if full floating would be the way to go, they are semi-floaters now. Some guys seem to not like the extra noise and regret going to full floaters. I don't know how good the stock units were, I like them to last more than 14,000 miles.

So what do folks recommend? The Ferodo cast irons are only $250 for two and I've had some on my beemer for about twenty years so I'm familiar with the rust issue.
They come in full floating versions so what do ya'll say?

Zach
03-12-2006, 10:26 AM
Last summer I just replaced the stock rotors on my '99 900SS. They had 48,000 miles on them. I 'upgraded' to the snowflake rotors (found on later 996s & ST4S & Aprilias). They seem to work just the same but look cooler to me than the stock pepperoni rotors. I now have 10,000 miles on the new rotors, no problems.

Cheers,
Zach

flyingducman
03-12-2006, 10:39 AM
Last summer I just replaced the stock rotors on my '99 900SS. They had 48,000 miles on them. I 'upgraded' to the snowflake rotors (found on later 996s & ST4S & Aprilias). They seem to work just the same but look cooler to me than the stock pepperoni rotors. I now have 10,000 miles on the new rotors, no problems.

Cheers,
Zach :sign18: 58,000 miles on the bike??? Any major mechanical problems along-the-way?

flyingducman
03-12-2006, 10:45 AM
Anyone for brake rotor disc cussion ?Nice 'word-play' :D .

Zach
03-12-2006, 10:46 AM
Not yet....have just tried to keep up with the regular maintenance.

Mat
03-12-2006, 02:46 PM
Oh my, there is much water that has passed under this bridge.
I have 18K on my ST3 and am on my 3rd set of rotors.
This is a major problem, especially for the ST line. A little more weight to stop.
I have treated mine with kid gloves, made sure that the spools were loose and the problem continues to arrive like clockwork.
I do not ride the brakes. The disks are always in spec for run-out and thickness.
From what I have read, the wave rotors are a cure for this and if you are paying for the new ones and they are not on warranty...the wave is about the same price as Brembos.
Someday, mother Brembo is going to explain why their premier rotors have constatant issues on ST Ducks.
Good Luck..
I just purchase "new" rotors on Ebay when they show up and wait for the truth to come out.

Jim is Cool
03-12-2006, 10:17 PM
I have 12K on my ST4s and actually use the bike and the brakes. There is NO issue at all, I did however replace the pads right away to the EBC HH's so maybe that's why I didn't have any issues.

Full floaters on the street are overkill and you'll probably wear out the carrier due to the buttons moving so much.

Cast iron is good, but you have to watch them, they tend to get hairline cracks from the cooling holes (spiderweb). Worst case is they'll explode.

I see absolutely no problems with the stock brembos rotors.

Mat
03-13-2006, 07:12 AM
I see absolutely no problems with the stock brembos rotors.

It may just be my bad Karma or that I continue to get Monday/Friday Rotors from Mother Brembo but Brembo knows that they have a problem and continue to warranty them. There must be fish here somewhere.
Just one question, do you carry luggage and passengers (weight!)?
I noticed that my first feeling of the warped came right after, I, my tootsie and our luggage (2 sides and a rear) got hauled down real fast from 85 to 50 on Hwy 2 in Montana when a truck changed lanes.
Now I treat them with great gingerness and pray that the last set were made on Tuesday-thru-Thursday....or that my Karma has improved.

Jasper
03-13-2006, 09:59 AM
Thanks all for the comments. Seems like something is going on with these rotors, I see the complaint quite alot and never with the beemer rotors and the stockers are probably Brembo. There are some throttle happy guys in the BMW camp as well so I don't think it's a enthusiasm issue.

Jim is cool - Carrier wear is something I hadn't heard or thought about, probably a good point.

Mat - I ride one up and so far with light load but I've only put about 1,500 miles on it, the last guy bought it used and put most of the miles on it, and I imagine most of the wear. He was tweaking the chip on a Hayabusa to get some more ponies out of her when I showed up to check it the Duc so I suspect the brakes weren't babied but I'm wondering if it isn't a pad material issue more than anything. I'll make sure to get a good match next time around.

Jim is Cool
03-13-2006, 10:02 AM
Just one question, do you carry luggage and passengers (weight!)?


I've done a few 2K trips with full luggage, one passenger. But I have used it on the track and I trail brake pretty deep. So think of the heat being generated at 150mph down to 80, then the fact that there isn't a lot of time between braking sot he heat never really gets dispersed.

I still bet the Brembo pads are too hard, generating too much heat etc. The fact that your disk is wearing down that fast is telling me that those pads are WAY too hard and abrasive. It sounds like the rotors are wearing out before the pads.

When you ride, do you "cover" the front brake all the time?

Mat
03-13-2006, 02:17 PM
The fact that your disk is wearing down that fast is telling me that those pads are WAY too hard and abrasive. It sounds like the rotors are wearing out before the pads.

When you ride, do you "cover" the front brake all the time?

I did not mean to communicate that the disks were worn....when they were replaced (both times) they were at high end spec. Not a disk wear issue.
I will try 'softer' pads (that is a good suggestion) but I suspect if pads were the fix, Brembo would have been on that in a heartbeat.....pads and their replacement are far cheaper than rotors and their replacement. Heck, I am not even sure that warranty covers pads.
Lastly, no, I do not cover the brake. The disks showed no signs of heat, or wear for that fact, when they were replaced.
This problem seems to be most prevalent in the 2004 and later ST3 and ST4's.
I will go forth and seek new pads just on the off chance.........
Above all, I appreciate the advice.

Jim is Cool
03-13-2006, 02:29 PM
Sorry, thought I read the "wear" issue somewhere in the thread.

One thing to try as well, get floating buttons, and just replace the buttons on your stock rotors. Since they're lighter than cast iron's the carrier might not wear.

Gordo
08-05-2009, 08:09 PM
Just hade the locking discs fall out of the brake rotor while securing front tire. Does that mean I need to buy new disc assemblies? It is a ST4 with 23,xxx miles.