The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: rob650 on April 28, 2009, 05:18:11 PM

Title: Can we resurface the brake rotor?
Post by: rob650 on April 28, 2009, 05:18:11 PM

Hi Everybody,

Rebuilding my caliper + new pads soon, and thought about getting the rotor resurfaced.  Mine looks in good condition without major grooves, though not "mirror" flat if you run your hand over it.  I don't have the funds for a new rotor right now.

I've never heard of doing this to a bike rotor and wanted to ask.  I know car rotors have minimum thickness limits for the purposes of resurfacing, do ours?

Thanks

Rob

Title: Re: Can we resurface the brake rotor?
Post by: Bob_Roller on April 28, 2009, 05:56:24 PM

The rotors are stainless steel, and very difficult to true up on a lathe, .180 in. is the minimum rotor thickness.

There a few after market rotors available, I've got EBC iron semi-floating rotors, and EBC graphite pads, and while the dry stopping doesn't appear to be noticeably increased, wet braking is greatly improved over stock rotors and pads.

Title: Re: Can we resurface the brake rotor?
Post by: Rob Valdez 79 R65 on April 28, 2009, 06:07:47 PM

I recommend saving your money for a new rotor.
Yours will probably be serviceable for some time, yet.

I ran mine for a long time with pronounced grooves, and it still stopped me well.
I replaced it with a EBC like Bob.

Title: Re: Can we resurface the brake rotor?
Post by: montmil on April 28, 2009, 06:27:00 PM

Quote

...I ran mine for a long time with pronounced grooves, and it still stopped me well...

X2 for Bob's comments. [smiley=thumbup.gif]

My '81 has definite grooves in the front rotor. The brakes pads will wear/bed in to a conformation with the rotor and will stop you pronto.

Milling the rotor is a waste of time and money as the stainless steel rotors, once well grooved, will afterwards be too thin for safe operation. Fugitaboutit.

My '83 has a new rotor and I'll be dipped n' clipped if I can tell a difference in braking performance.

Now, if only I could do something about the old school-quality braking of the rear shoes. :(

Monte

Title: Re: Can we resurface the brake rotor?
Post by: Bob_Roller on April 28, 2009, 06:57:38 PM

When I finally replaced my rotors, the high spots on the rotors were at .180 in., with .060 in. deep grooves on each side.

I had about 79,000 miles on the rotors before replacing them.

There's a company, I believe it's Spiegler, that will drill out the rivets on your OEM rotors, and replace them with stainless semi-floating rotors, for about the same price as aftermarket rotors.

http://www.spieglerusa.com/BMWConversions/