Rusty brake discs...

[T0MMY]

This is a bit odd...one of the stainless discs on my ZX6R trackbike has gotten quite rusty on one side since Saturday when I last used it. The bike lives outside in the rain and has done since I've had it and this has never happened before. I haven't changed my pads or anything so it isn't something to do with the pad compound.

It's a bit confusing really...I've been getting serious front end judder under braking the last few times out on it so I went round the discs last week and freed off all the bobbins which might have helped temporarily but it was still juddering by the end of the day.

Could this be something to do with the disc over heating on one side if it shifted when I freed the bobbins but then seized again when it got hot in a new position? Alternatively I was thinking it might be to do with the pads overheating and leaving material on the disc which is either itself oxidising or causing a reaction with the stainless steel?

Any ideas?
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ZX6R + CBR600RR

[jjdugen]

Yurs is about the third or so post with this problem, all 600 Kwaks of a 'certain' age. Mine has been doing this for a while if left, so bad that the pads stick hard on. Its not caliper rot or sticky pistons its the discs themselves. I generally make sure I give it a spin every week to keep them clean. Looks like some discs have a higher iron/steel component in the mix?
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The CBR900RR has been sold. Aprilia Falco worms its way into my heart.
Try Soi 23 on Amazon for a good read.... Self promotion? Moi?

[T0MMY]

But I've had the bike since last summer and this has never happened before. In fact, it stood for nearly a month recently whilst I was working on it and it rained regularly with no rust appearing. The bike was used 2 days ago at Snetterton. It's also odd that it's only on one side of one disc.

I'm not that bothered about the rust in so much as it'll come straight off when I use it next but I'm sure this has something to do with the brake judder problem I have which is what I really want to get to the bottom of...

I suspect this is something to do with the disc running on the pad too much and overheating due to sticking bobbins or seized pistons maybe?
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ZX6R + CBR600RR

[Walloper]

Maybe just iron dust has settled on one disc not in the rain wind and rusted on. Rust will stick to other iron bits.

Clean it off the discs using some wet/dry 600. Clean out the callipers too to remove any brake dust build up that may be there.

I oil my brake discs as I seldom use the brakes anyway.
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W-ireless A-rtificial L-ifeform L-imited to O-bservation P-eacekeeping and E-fficient R-epair

[daesimps]

It's not just Kwaks of a certain age.

My mate is currently doing battle with Triumph. He bought a brand new Speed Triple last March and between him getting it and October he had 4 replacement discs.

He uses the bike as his only form of transport. He was finding that each morning when he got to the bike the disc and pads were stuck together. Rocking the bike got it freed, but it was causing pitting in the discs. After a couple of weeks he could feel real issues through the bars under braking.

Each time Triumph replaced the disc and the problem disappeared for a couple of weeks. Bear in mind that this was over summer, so it's not like road salt was playing a massive part in it. He keeps it in a garage, so it's not being left out in the rain.

After the fourth time Triumph said they'd not perform any more warranty work on his brakes as it was his fault. They said that he should dry the discs by hand when he parks up if they are wet. This is even though it's not mentioned anywhere in the manual and there's the potential safety issue of hot discs meeting hands.

He said that this is utterly ridiculous - it's a British built bike that was sold in Britain, where surprisingly enough it rains. Surely it should be able to handle a trip or too in the rain.

He even offered to pay half towards the Brembo discs, but Triumph refused. They said that since his bike wasn't originally supplied with those discs it would invalidate the warranty, even though those discs are an option when you purchase the bike. This doesn't really make any sense, given that they've already said they won't entertain any more warranty work on the brakes anyway.

I've seen the photographs of the discs after a week and they look like they are many years old.

It's made him decide to never by another Triumph and regret getting the one he has. He has had really good service from the dealer, but unfortunately it's Triumph themselves that won't let the dealer do any more for him.

All information in this post his what he's relayed to me and some that I've seen first hand, so I can't really give any more details.

I don't know what's happening now, but last time I spoke to him at Christmas it was getting legal.


Dae.
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If it ain't broke, fix it till it is!

[T0MMY]

Well I rode the bike today so the rust is gone I went back round the bobbins and found I had missed one that was firmly seized. It was on the disc that had rusted so I think it was to do with the disc or pad overheating on track because it was rubbing.

I'll see if my juddering is reduced now but it's hard to test on the road as it's at it's most noticeable when braking very hard from 150+
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ZX6R + CBR600RR