Rotor grinding

[larrys]

Taking my Cal 1100 apart for some much needed maintenance. Brakes, tires, fork seals, etc. Who would you guys recommend to have my front rotors ground? What's the minimum thickness for the rotors? I'm interested in tire choices, too. Have Metzler touring tires now. May get them again, got many miles out of them.
TIA,
Larry

[guzzisteve]

New ones replacement are 5mm thick, minimum spec is not listed in Cal 1100 book

https://www.mgcycle.com/index.php?main_page=product_info&cPath=110_134&products_id=1108

[PeteS]

Not sure its a good idea to grind stainless rotors. They will just warp again. OK for Cast iron rotors.

Pete

[Antietam Classic Cycle]

Who would you guys recommend to have my front rotors ground?

https://truedisk.net/

[turboguzzi]

are you suffering from lever pulsing while braking? any signs of uneven pad contact?

if answers are no & no, you dont have to.

[larrys]

The rotors aren't warped. The right front however has some grooves in it from the caliper locking up some years ago. I rebuilt the caliper and installed new pads, they wore into the grooves and the brake works as it should. Since I'm taking the front end apart already, I figured I'd clean up the rotors while I'm into it.

https://truedisk.net/

Charlie, thanks I'll check them out. Will mic the rotors first to see if grinding is even an option.
Larry

[Antietam Classic Cycle]

The rotors aren't warped. The right front however has some grooves in it from the caliper locking up some years ago. I rebuilt the caliper and installed new pads, they wore into the grooves and the brake works as it should. Since I'm taking the front end apart already, I figured I'd clean up the rotors while I'm into it.

Charlie, thanks I'll check them out. Will mic the rotors first to see if grinding is even an option.
Larry

Cast iron rotors. IIRC, minimum is 5.8 mm.

[larrys]

Cast iron rotors. IIRC, minimum is 5.8 mm.

Crap. The worst one mic'ed at .217"= 5.5118 mm. Who makes a decent aftermarket rotor?
Larry

[n3303j]

Crap. The worst one mic'ed at .217"= 5.5118 mm. Who makes a decent aftermarket rotor?
Larry

Cast iron rotors require a lot more thickness than stainless steel.
Find the published minimum dimension for your stainless steel application.

[bigbikerrick]

 FWIW,I had a local machinist smooth out the front discs on my goldwing some years ago. They were stainless, and he said he used a "flywheel machine" to smooth them out,and they came out great, no more pulsating.
Rick

[Wayne Orwig]

My book covering cast iron ones shows 5.8mm minimum also.

[n3303j]

Quick Google search often mentions 4.5 to 4.6 millimeter as being the minimum finished thickness for stainless steel rotors. That was for the likes of Ducati and BMW vintage machines.

[Antietam Classic Cycle]

The original rotors are not stainless like on the EV and later bikes, they are 300 mm cast iron rotors. Speigler sells stainless replacements, which could be ordered through MG Cycle.

https://www.mgcycle.com/index.php?main_page=product_info&cPath=110_134&products_id=1108

[PeteS]

If these are cast iron, it might be worth it to have them ground. I found the rotors on my ‘76 LeMans pulsated but not because they were warped but rather the thickness varied. Had them ground by the owner of my local Honda Dealer who had access to the proper grinder. He ground both sides of the rotor plus the back of the carrier. Its been fine since over the last 40k hard miles.

Pete

[larrys]

Yes they are cast iron, not stainless. The worst rotor mic’ed at .217”= 5.5mm which is less than the 5.8mm minimum that Charlie stated. I would be interested in a set of aftermarket rotors. Recommendations?
Still looking for some advice for new tires.
TIA,
Larry

[Antietam Classic Cycle]

Yes they are cast iron, not stainless. The worst rotor mic’ed at .217”= 5.5mm which is less than the 5.8mm minimum that Charlie stated. I would be interested in a set of aftermarket rotors. Recommendations?
Still looking for some advice for new tires.
TIA,
Larry

As I posted previously...
Rotors: https://www.mgcycle.com/index.php?main_page=product_info&cPath=110_134&products_id=1108

[larrys]

As I posted previously...
Rotors: https://www.mgcycle.com/index.php?main_page=product_info&cPath=110_134&products_id=1108

Onliest choice for new from what I can find. 
Larry