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K100-forum.com » Technical, repair and troubleshooting » Frame, fairing and wheels » Warped discs from corrosion

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1Back to top Go down   Warped discs from corrosion Empty Warped discs from corrosion Thu Jul 22, 2021 9:36 pm

Snod Blatter

Snod Blatter
Life time member
Life time member
Hi all, I've had some warped discs on my K for a while now, it's so bad that it knocks the pads away and I have to pump the front lever to be able to stop! I assumed it was rust on the (cast iron) discs again, but looking closer I see that it's actually probably caused by some serious corrosion between the carrier and the outer disc. Observe:
Warped discs from corrosion SBFcaTZ
Has anyone else experienced this? It's from the salt in the winter, and sitting outside.. I now have a garage for her to live in ( cheers ) but I'm too late to stop this from happening.

Is the carrier salvageable if I take it to bits and wire brush it? It seems like it'll be a lot of work, the little nuts for the disc refuse to budge with an open ended spanner on them so I'll have to get a socket on them, but to do that I have to remove the ABS ring and I have a strong suspicion it's gonna fight me all the way!

Alternatively, if anyone has some nice non-rusting ABS discs for sale, I might be tempted.. Even better if they're those fancy EBC semi floaters Warped discs from corrosion 652573


__________________________________________________
1989 K100RS SE ABS 8v  VIN: 0149214
Others: 1.5 x CBX250RS-E, '94 CB250, '95 TRX850, '16 Z250SL, '01 R1100GS
http://justbikethings.blogspot.co.uk/
    

2Back to top Go down   Warped discs from corrosion Empty Re: Warped discs from corrosion Fri Jul 23, 2021 12:46 am

92KK 84WW Olaf

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Life time member
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If its 8v K I don t think they float. I have EBC on one of mine.


__________________________________________________
1992 K100LT 0193214 Bertha Blue 101,000 miles
1984 K100RT 0022575 Brutus Baja Red 578 bought 36,000 now 89,150 miles
1997 K1100LT 0188024 Wotan Mystic Red 689 58,645 now 106,950 miles Deceased.
1983 K100RS 0011157 Fricka 606 Alaska Blue 29,495 miles Damn K Pox Its a Bat outta Hell Now 58,200 miles. 
1996 K1100LT 0233004 Lohengrin Mystic Red 38,000 miles currently 51,800 miles.
1983 K100RS 0004449 Odette R100 colours 58,000 miles. Sprint fairing now 63,390 miles

Past:
1968 Yamaha 80 YG1
1971 Yamaha 125 YAS-1
1968 Honda 125 SS
1970 Honda CD 175
1973 Honda CB500-4
Honda CX 500
    

3Back to top Go down   Warped discs from corrosion Empty Re: Warped discs from corrosion Fri Jul 23, 2021 1:04 am

MartinW

MartinW
Life time member
Life time member
I bought these about 6 + years ago from Motorworks UK. Ordered on Monday they arrived on Friday, from memory they were on special $400.00 Au including freight. I don't have ABS and still waiting to use them.
Regards Martin.
Warped discs from corrosion P7230010
Warped discs from corrosion P7230011


__________________________________________________
1992 K75s
    

4Back to top Go down   Warped discs from corrosion Empty Re: Warped discs from corrosion Tue Jul 27, 2021 1:16 am

Snod Blatter

Snod Blatter
Life time member
Life time member
No one else has abused their bike this badly? Just me? Dang it..


__________________________________________________
1989 K100RS SE ABS 8v  VIN: 0149214
Others: 1.5 x CBX250RS-E, '94 CB250, '95 TRX850, '16 Z250SL, '01 R1100GS
http://justbikethings.blogspot.co.uk/
    

5Back to top Go down   Warped discs from corrosion Empty Re: Warped discs from corrosion Tue Jul 27, 2021 1:37 am

MartinW

MartinW
Life time member
Life time member
I've had a pulsating problem twice in 20 years. I have successfully straightened warped discs. We are talking minor warping not major buckles. If you don't have patience and restraint read no further and get another disc. Be warned it is a slow process requiring lot's and lot's patience and a delicate touch, and only works on solid rotors not floating ones. Set the bike up so the front wheel is off the ground. You need to remove the calipers and attach a dial gauge indicator (DGI) with whatever you can rig up solidly to the top caliper retaining bolt. It needs to be set up so it runs on the outer most edge of the disc, and can be rotated away from the disc when adjusting the warp. This will only work if the disc has a smooth track to run on, if it doesn't forget it. With the DGI set up to run on this track rotate the disc a determine where the warp is and how big it is and mark with a pencil this part will be repeated after each adjustment. To remove the warp you will need a piece of  broom handle 10" - 12" long and a plastic hammer. The next bit requires patience and a delicate touch. Rotate the DGI so it is clear of the disc and place the end of the broom handle on the outer most edge of the disc carrier (not on the disc) where you marked the position of the warp, and tap gently with the plastic hammer.  If the warp is bulging out from the centre you need to tap it in. If it is bulging in need to tap it out. When tapping it out, the broom handle will be running at an angle this is the reason for it's length. You need to realign the DGI after every tap and check that you have moved it and by how much. Under no circumstances belt it or hit it hard, you will eventually get a feel as to how hard to tap it believe me it won't be a lot. Hitting it hard will only push it too far and will require you to tap it back the other way. You need to avoid tapping it to and fro, this will happen occasionally but needs to be reduced to the minimum. You are aiming for a figure under .007", well under this can be achieved with patience.
Regards Martin.
Warped discs from corrosion Bmw_ro11


__________________________________________________
1992 K75s
    

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