can brake rotors be ground?

Can a drilled / slotted brake rotor be ground flat and true, and if so who does that kind of work? Looking to not mail it somewhere and lose riding time.
Thanks

Yes they can be Blanchard Ground. shops that true up clutch pressure plates would be where to look but be careful as to how much is remaining on the thickness. You can buy them already pre-drilled If you look around. Check the latest INOA rag. FluidSix does this work. http://www.fluidsix.com/

They can, but Commando rotors start life fairly thin compared to many, and a new standard rotor is relatively cheap....I guess your issue is you need to drill/slot again, but it isn't such a brilliant idea with cast rotors anyway!

So personally, I would say yes you could find someone, but it may not be a good solution.

Disk Brake Reconditioners used to do all of mine. Excellent work every time.

I believe they did more than 20 rotors for me over 13 years.

maylar said:

Can a drilled / slotted brake rotor be ground flat and true, and if so who does that kind of work? Looking to not mail it somewhere and lose riding time.
Thanks

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Can’t go wrong with Tom Tokarz at Tru Disc - I believe they are in Michigan so you will have to mail

I had a disk drilled & ground at True Disk. Extremely pleased.
https://truedisk.net

Tom Tokarz did my front disc also. Based on prints he showed me he knows what to use as the reference surface for grinding. While Norton discs are thin it only took about .008" total between both sides to true my disc. He also drilled the disc for gas evacuation and web area for lightening. Excellent job at reasonable cost. Fast turn-around. He is in Carleton, MI.

oldbeezer said:

I had a disk drilled & ground at True Disk. Extremely pleased.
https://truedisk.net

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+1 on Truedisk. I've had several Norton and Triumph disks done by them - very happy.

myron1950 said:

Tom Tokarz did my front disc also. Based on prints he showed me he knows what to use as the reference surface for grinding. While Norton discs are thin it only took about .008" total between both sides to true my disc. He also drilled the disc for gas evacuation and web area for lightening. Excellent job at reasonable cost. Fast turn-around. He is in Carleton, MI.

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Very nice And even better to see that the tyre has been correctly position on the rim

Aren't most Commando rotors chromium plated ?

acotrel said:

Aren't most Commando rotors chromium plated ?

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Not after they are ground.

Probably thinking of later Triumphs.

acotrel said:

Aren't most Commando rotors chromium plated ?

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That is how they left the factory.... Though removal of the plating was considered a 'good thing'

The hardness of the surface affects the coefficient of friction. The discs I use are Japanese - high speed steel - it contains a bit of chrome and a bit of nickel. It is not as hard as chromium plating. You need pads and disc materials which are compatible to get good braking. Cast iron gives good friction with asbestos pads, but has a low tensile strength, so is dangerous.
Commando discs are designed for a certain purpose. Removing the chrome changes the design.
There is a difference between toughness and hardness. By removing the chrome you might get better friction, but the disc might fail if it is not tough enough to withstand the extra loads. I don't play much with brakes because it is too risky. Even changing the pads to get more friction is a bit sus. What you take for granted with the front brake can kill you.
Over the years, I've known two guys who were killed by brake failure - Rob Moorehouse and Ross Barelli - both at Bathurst, where you really do not need brake failure.

I tried using carbon racing pads with my twin high speed steel discs and probably could not get them hot enough - useless. The asbestos pads with the single chromed disc were just a joke - unsafe at any speed. However - better than a drum.