Brake rotor thickness

Does anyone have the specs for the allowable minimum front brake rotor thickness on an XJ750J?

Any thoughts on turning used rotors.......besides mnimum thickness, any other concerns I should be aware of?

 

If you have solid rotors the thickness should not be less than 5mm when measured with a good digital caliper.

If you have the vented rotors then around 5 - 6mm should be OK.

Here in Australia when I got my refurbished XJ registered it had to pass a roadworthy test part of which was minimun thickness for brake disks.

They will work fine below that but if used under consistent braking involving high temperatures it increases the possibility of warpage.

 

Found this information in the Yamaha XJ750RH manual:

Brake disc minimum thickness 4.5 mm ( 0.18 in. )
seems pretty thin, only 3/16"

Brake disc maximum deflection 0.15 mm ( 0.006 in. )

 

Thanks guys. Well, I have brake rotors that are SUPPOSEDLY off a '82 XJ750J but they are slotted, with a raised (or recessed, depending on which side you look at it from!) center hub section.

Does anyone have the specs for these rotors?

BTW, I took them to a local brake shop and asked them to give them a quick turn to clean them up, and they said that they can't because....this is wild.....they are stainless steel and no one has cutting stones that will cut stainless! A motorcycle guy I know said to take them to an engine machine shop and have them surfaced on a flywheel grinder.........wow.

 

Yup.. Fywheel grinder works Problem is the cost
Paying $50 for a flywheel resurfce is no Big Deal it only has one surface.. But yer Moto discs have 2 surfaces each and Shops invariably charge by the surface.... so yer getting up into aftermarket prices for brand new ones.
tough choice.

 

Yeah, but.........I have a friend who works at the shop so he'll do it basically for free. I just need the specs so I can determine whether it's
even worth doing......!

 

Found the same specs as I quoted before in a Yamaha XJ750RH~RK (81~83) manual.