Can these discs be saved?

[R1stu]

As per title really. My mate thinks we can rescue these. I on the other hand, am not so sure.

https://imgur.com/a/tz2GtCk
____________________
Carbon closet tart! https://www.bikepics.com/members/r6stuk/02r6/
Stolen bike. 2000 R1: https://www.bikepics.com/members/r6stuk/00r1/
Current bike 1991 Honda ST1100 Pan European, 1986 Honda cb350sg (Finished)

[jaffa90]

Is it surface rust or are they pitted?

[nowhere.elysium]

[skatefreak]

If they are not pitted and its just surface rust then I would whack them on and sheepishly ride up and down the street and 'wear' them back in...

If they're pitted the would need skimming which could potentially leave them below serviceable thickness and generally frowned upon with bike disks.

[R1stu]

will get a better look when home, I thought at least one looks like eggshells
____________________
Carbon closet tart! https://www.bikepics.com/members/r6stuk/02r6/
Stolen bike. 2000 R1: https://www.bikepics.com/members/r6stuk/00r1/
Current bike 1991 Honda ST1100 Pan European, 1986 Honda cb350sg (Finished)

[Riejufixing]

[RhynoCZ]

Perfectly alright, check the thickness.
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'87 Honda XBR 500, '96 Kawasaki ZX7R P1, '90 Honda CB-1, '88 Kawasaki GPz550, MZ 150 ETZ
'95 Mercedes-Benz w202 C200 CGI, '98 Mercedes-Benz w210 E200 Kompressor

[pepperami]

I’m gonna bet that under that surface rust, they’ll be alright.

I guess it might depend on what you intend to attach them to?
Would I attach them to my newly refurbished R1busakawabird?, no.

However my smaller hack ride, possibly, I might give them a try.
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I am the sum total of my own existence, what went before makes me who I am now!

[MCN]

There is only one way to find out.
Ask an engineer to cut the rust off to remove the pitting.
They only need to cut enough shit off to allow the clean metal to be measured with a Mic.
If under-size then u lose.

The rust has to come off or it will affect the braking. The rust will grind off and pack into the brake pads rendering them useless.
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Disclaimer: The comments above may be predicted text and not necessarily the opinion of MCN.

[R1stu]

[Teflon-Mike]

What are they off/for?
If they are stainless discs..... to be that bad, then they are probably shot.
If they aren't stainless... Grimeca/Brembo wop-fitment, Morini/Guzzi/Ducati etc.... they look pretty normal.... Er-Nibs Italian Tractor's rotors don't look much different the morning after she'd had a solvol binge!!!!
Two things that would be on my mind are thickness and warpage; then if re-fitted to bike, the pads.
Used to be more common on older race-bikes to 'upgrade' stainless rotors to cast; Pads for stainless rotors are softer, because the metal isn't; so using soft pads for stainless discs on cast would see the brakes very grabby and chewed up in short time.
Going the other way, and using harder pads for cast discs on stainless discs would result in wooden brakes, and rider applying gross lever pressure to get some effect, and often the discs warping and getting scored.
Was most often observed on things like air-cooled RD's and stuff with folk mixing and matching TZ race bits, and the common one of 'upgrading' wire wheels for cast, but keeping the wires to mount 'wets', whilst slicks or race tyres fitted to the mags; but leaving whatever discs were on the wheels, so that the discs got mis-matched when swapped.
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[sickpup]

[Riejufixing]

[pepperami]

[Pete.]

Buy 1/2 a kg of citric acid crystals off ebay. Fill bucket with boiling water, dissolve as much of the citric as possible and dunk the discs in for a couple of hours. All the rust will be gone leaving a black film which will wipe right off.
Citric acid is totally safe (it's a food additive) and non-toxic so pour it down the drain when you're done.

Done this week: two small lathe chucks 90 minutes in a bucket of hot citric acid solution. Here's the before and after pics.
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a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[RhynoCZ]

[Riejufixing]

[R1stu]

I have brought new discs with the eBay voucher, however here are some pics.

To me there looks like too much pitting.

https://i.imgur.com/aSYLaNt.jpg

https://i.imgur.com/qrJ9uQa.jpg

https://i.imgur.com/ivR5BXI.jpg
____________________
Carbon closet tart! https://www.bikepics.com/members/r6stuk/02r6/
Stolen bike. 2000 R1: https://www.bikepics.com/members/r6stuk/00r1/
Current bike 1991 Honda ST1100 Pan European, 1986 Honda cb350sg (Finished)

[R1stu]

[Riejufixing]

[MCN]

[stinkwheel]

[tom_e]