Disc rotor

I picked up a chromed disc rotor recently and would like to use it without the chrome finish. Has anyone had the chrome removed before. I’m not sure whether reverse chrome process would cause embrittlement or grinding would make it too thin. Any thoughts.

Don’t know if reverse chrome will alter the elasticity- better minds than mine will have to answer that . The rotor will benefit from Blanchard grinding so if there is a shop in your part of the world that offers this service I would contact them and see if they can grind with the plating in place .

A plating shop should be able to strip the chrome off.

Richard Tool said:

The rotor will benefit from Blanchard grinding

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And completely remove the chrome plating such that it should not qualify as hazardous waste. A couple of suggestions:

1) Scrub the disk with a wire wheel with primary attention to the non friction surfaces. Chean with a solvent that doesn't leave residue, isopropyl alcohol is good, then paint it with a high temperature color of your choice. The person who grinds it will remove unnecessary paint.

2) Chase the 5/16-24 threaded holes the disk fastens to, blow out any shwarf and follow up with a Q-tip that is dampened with a light oil, 3in1 is my choice. Bolt the disk to the hub with proper and equal torque. Mount the axle in a vice, place the hub with brake on and check for run out. If you see more than .004" mark the diack and the hub at that high point and remove the fasteners, rotate the dick to the next hole, check again, repeat until get less than .004" or a pattern emerges. If one of the positions eliminates, or lessens the run out; job done. If the run out persists you may be able to correct with a light sanding, but don't get too aggressive. The hub run out can also be the result of a group of adjacent spokes that are too tight or loose. You can check for tight/loose spokes by striking them individually and listening to the "music"; loose or tight spokes will quickly speak up.

Beware that the Norton front wheel that mounts the disk is the hardest, worst and most complicated setup ever created in the entire universe of spoked wheels...

Best.

I had some heavy duty "Green Devil" crystal drain cleaner strip off the chrome of my bathtub drain opening once. Maybe that would do a nice job on a brake rotor disc?

I had Tom Tokarz of Truedisc LLC grind my front rotor to square it relative to the mounting surface. Total material removal was .008 inch which relative to the nominal .250” thickness does not concern me.

Modulus of Elasticity will not be affected by chemical removal of chromium. The process of Chrome plating can cause hydrogen embrittlement without proper bake out (as I recall upward of 4 hours at >375F). I’m not sure if there is any risk of similar embrittlement on chemical removal – I relied on the Blanchard grind process to remove the chrome and true the disc.

Usually a plating shop will strip the chrome for not a lot of money.
I wouldn't rush to getting it ground. After it is stripped, mount the disk on the wheel and try it. If the chrome is good, there is every chance the disk will run true.
Roadscholar's advice to "clock" the rotor is sound, as you will probably be able to reduce the runout.

tyborg15 said:

I picked up a chromed disc rotor recently and would like to use it without the chrome finish. Has anyone had the chrome removed before. I’m not sure whether reverse chrome process would cause embrittlement or grinding would make it too thin. Any thoughts.

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Cost?

How much to buy a new unplated disc rotor?

Trade of against costs of 'unplating' by any method!

Sell on the chromed one. Someone may want it on a show pony!

Get rid of the original disc all together, buy a new one or upgrade to a better disc or a complete new system, your brakes are your life so spend the money and upgrade, my original front brakes let me down after complete rebuild and I didn't take notice and still tried to make the original bakes work better but the second time they let me down again and could have been worst than what happened still walked away with my first broken bones and while recovering I upgraded to a full new Grimica front brake system and now I have full modern brake system that is as good as my modern Triumph Thruxton brakes.
It woke me up that 40 year ++ old brake system is not up to it today and my life is more important than trying to fix up a old system, yes I rebuilt the original system a few time over the the years of owning since new and reducing the MC , but one day was working fine then the next day without warning tried to kill me in a emergency, so 7 years ago now since I upgraded to the Grimica front brake system was one of the best upgrades I done to my old Norton and I did it at the time for just on $500 for a complete front brake system that works better than the old stock system even when new.
This is my opinion and a lot want to keep original but I ride my Norton hard as with all my bikes, but I want to stop safely when needed and one day your 46 year ++ brakes will let you down and in a big way, don't go cheap on brakes as your life might depend on them one day.

Ashley

Tom Tokarz at True disc does topnotch work - did some rotors for me and I can recommend him unequivocally but as the O P is halfway around the world he may be able to find someone closer .
As to clocking the rotor, indeed a benefit- IF you are not having it ground by the Blanchard process . The process includes truing the mating surface where the rotor meets the hub and producing both vertical planes of the rotor parallel AND perpendicular to the axis of rotation - important in non - floating systems as employed by the original front brake . All above assuming that the mating surface on the hub is true and perpendicular to it’s axis of rotation .

Richard Tool said:

important in non - floating systems as employed by the original front brake

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I don't disagree, but the less you ask a floating disk to "float" the better the braking; I check those as well.

Best.

RoadScholar said:

I don't disagree, but the less you ask a floating disk to "float" the better the braking; I check those as well.

Best.

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Depending on the manufacturer, and quality, 'floating' is a bit of a misnomer and leads to different levels of understanding.

I certainly agree that the disc should be asked to float as little as possible. I had one on a track bike get excessively hot and turned itself into a clutch diaphragm spring, flipping each time the brake was applied, and pushing the pads back as it was released, huge lever travel!

Most of us have imagined that the 'float' allows side to side movement, it may do, if it does, it theoretically allows the pads to centralise the disc on application. I am not sure that increases braking effect.

The image of a disc moving side to side every time you apply the brakes conjures up images of rapid wear in both disc buttons and caliper pistons and seals to me! I am not convinced that is what the brake manufacturers are trying to achieve.

But actually I think floating brakes allow different material choices, for example, EBC explain with their discs that the purpose of 'float' is to allow a hot disc to expand away from the centre of the disc and return to the centre as it cools. Reducing the heat distortion effect and maintaining the braking effect consistent over the life of the disc. I believe this affects the choice of braking material and allows higher coefficient of friction choices in both pads and rotors. That in turn improves braking effect.