The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: decorn33 on July 09, 2013, 10:16:09 AM

Title: Front Disc Rotor
Post by: decorn33 on July 09, 2013, 10:16:09 AM
On a recent weekend trip from New Jersey up to the Rhinebeck area in upstate New York I noticed that my front brake was starting to shudder when applied, so when got home I changed the rotor and pads out for new ones.  Looking at the old rotor I saw stamped in the rim of the casting "MIN 0.18".   By any chance does this mean that these rotors can be turned down to resurface them to a minimum thickness of 0.18?
Title: Re: Front Disc Rotor
Post by: Bob_Roller on July 09, 2013, 10:29:05 AM
Usually with the deep grooves that develop in the rotors, if they are machined to remove them, they are too thin for safe use .

My '84 LS had the rotors machined by a previous owner, I found 13 cracks between the holes in the rotor surface between the two rotors .
Title: Re: Front Disc Rotor
Post by: Lucky_Lou on July 09, 2013, 11:08:25 AM
I have just had a similar issue with my "K" I was advised that the discs are too thin to be ground so I got a new to me replacement on fleabay
Lou
Title: Re: Front Disc Rotor
Post by: georgesgiralt on July 09, 2013, 12:28:11 PM
The information stamped on the rotor indicate that this thickness it the absolute minimum.
If you measure your rotor at the thinnest point, you'll find them under the 0,18 "
If the spacers are in good shape and not warped, you can buy new rotors and affix them to the spacers (on my R65, the riveted original rotors were replaced by screwed rotors... )
This is cheaper but may make you unhappy because the steel is not the same (sometimes cast iron) and braking will change.
Title: Re: Front Disc Rotor
Post by: decorn33 on July 09, 2013, 01:38:21 PM
Thanks for the information. It was worth asking.  I checked on Moto-Bins and they want $350 for a new rotor and spacer combo.  I had a new one on the shelf for a few years. Glad I did.
Title: Re: Front Disc Rotor
Post by: Matt Chapter on July 09, 2013, 02:02:11 PM
Don't forget that spiegler can "refurbish" your rotor if you send it to them.  cheaper than oem, plus a few other benefits such as drilling and semi floating options.