TrueDisk

[blackcat]

Before I send out the discs from the LeMans which has 17K on the clock if that is to be believed, the following thicknesses in the pad area:

Front Right: 5.6mm
Front Left: 5.2mm
Rear: 5.1mm

None of the discs pulse when used though there does seem to be a slight dip in the front left. I do have a call into Tom at TD but he hasn't called me back. Anyway, just curious what others think about the thickness of these discs.

[Alfetta]

I don't know if those are within tolerance, but assuming they are, why are you sending them out?

[Huzo]

Before I send out the discs from the LeMans which has 17K on the clock if that is to be believed, the following thicknesses in the pad area:

Front Right: 5.6mm
Front Left: 5.2mm
Rear: 5.1mm

there does seem to be a slight dip in the front left.

What do you mean by a “dip” ?
Are you referring to a patch of reduced thickness ?

[blackcat]

What do you mean by a “dip” ?
Are you referring to a patch of reduced thickness ?

Yes, there is one spot that is shallower then the rest of the disc.

"I don't know if those are within tolerance, but assuming they are, why are you sending them out?"

The surfaces are not as clean as the discs on my CX, and you can see the shallow spot right below the front fork.

[Huzo]

If there is no pulsing at the lever/pedal, I would be having them cosmetically brought back to what you require, but would not have the discs ground.
Seems like a needless reduction in the projected life span of them.
The “low” patch will eventually disappear as the rest of the disc wears down to that level.
How long has the patch been there, it’s not a localised contaminant is it ?
I’d be willing to bet that if you put a micrometer on it, it’d be lucky to read a half a thou’.
Just looking at it, there’s another patch from about 3 o’clock to 5 o’clock. I’d clean them in a suitable solvent, wash them in hot water and ride it.

[blackcat]

I've tried cleaning them with no luck but maybe I should try with someone more aggressive. On my CX there is a substantial ridge or likely the original starting point with the sweep area reading around the same thickness as the LM I.

This bike was in parts, sitting for many years in south Florida and I'm guessing the crud on the discs is related to that condition.

[RinkRat II]

       If you have a small right angle grinder, 3M makes Roloc discs in assorted grits that will clean and surface the rotors. NAPA has them also. I'd start with a fine compound and work your way up if necessary. I've used them for years on car rotors just to deglaze when installing new pads. My $.02

         Paul B 

[blackcat]

       If you have a small right angle grinder, 3M makes Roloc discs in assorted grits that will clean and surface the rotors. NAPA has them also. I'd start with a fine compound and work your way up if necessary. I've used them for years on car rotors just to deglaze when installing new pads. My $.02

         Paul B 

Thanks, have to look into those discs.

[blackcat]

The rotor should be stamped/embossed with its minimum thickness somewhere outside of the swept area.  If yours has it, (represented in mm like 4,7, 5,0, etc) then you know for sure.

Yes, I looked for those numbers but there were none.

[Scout63]

I’d call Tom Tozarz at Truedisc again. He is very knowledgeable.

[dxhall]

I just installed a set of stock Honda discs.  They were stamped, “min. thickness 3.5mm.”  I think you’re fine.

[lucky phil]

Yes, there is one spot that is shallower then the rest of the disc.

"I don't know if those are within tolerance, but assuming they are, why are you sending them out?"

The surfaces are not as clean as the discs on my CX, and you can see the shallow spot right below the front fork.

Unless that part you refer to as a a shallow spot does indeed measure as less thickness with a mike and you dont have any brake related issues then you don't have a problem. Areas that look like this can be caused by pads sitting on that part of the disk for prolonged periods of time and also uneven distribution of pad material on the disk. When fresh pads first contact the disk surfaces they wipe a layer of pad material onto the disk face and sometimes if the pads aren't broken in correctly you can get this on the disk. if the disk is a consistent thickness then you can buy a ball brush you fit in your hand drill to hone the disk surfaces and remove any residual pad material.

https://pdf.directindustry.com/pdf/brush-research-manufacturing/flex-hone-rotors/18081-139824.html

Ciao

[Canuck750]

The rotors are stamped on the edge like this, these are the set that are on my 750S, I beleive they are the same discs on the 750 S3. LeMans uses a different style of disc, can you find the  minimum thickness anywhere on the disc?

The Brembo discs on my 1975 Ducati 860 were too worn to machine and I had to buy new ones.

I have sent a dozen or more discs to Trudisc over the years, great service every time.

[blackcat]

The number could be on the disk carrier . . . just trying to be helpful.

I've gone over all three discs, even sanded them down in case the numbers were imbedded with some crud but nothing shows up.
 
"The number could be on the disk carrier . . . just trying to be helpful."
Have to look at the carriers.

"...if the disk is a consistent thickness then you can buy a ball brush you fit in your hand drill to hone the disk surfaces and remove any residual pad material."

I ordered one of those brushes today and will give it a try before sending out the discs. Didn't get a chance to call TrueDisk today but will talk to him tomorrow.

Thanks.

[Huzo]

you can buy a ball brush you fit in your hand

Jeez are you sure..?
It sounds painful..

[lucky phil]

Jeez are you sure..?
It sounds painful..

I thinks thats called selective editing

Ciao

[Huzo]

I thinks thats called selective editing

Ciao

Yep..
Never let the facts ruin a good story.

[lucky phil]

Yep..
Never let the facts ruin a good story.

You should run for PM

Ciao

[Huzo]

You should run for PM

Ciao

What.
Preferred moderator...?

[Scout63]

Sara keeps the ball brush in the drawer next to the micrometer.

[Huzo]

 

Sara keeps the ball brush in the drawer next to the micrometer.

[blackcat]

Just for the record, I didn't write this:

Quote from: blackcat on February 08, 2022, 05:15:12 PM
you can buy a ball brush you fit in your hand

[Dave Swanson]

Just send them (as long as you have enough material of course).  Nothing like rotors with the TrueDisk treatment and new pads.  AHHHHH.

His rates are quite reasonable also. 

[Frenchfrog]

I'm not certain but AFAIK the minimum thickness for those is 5.8mm. The number is perhaps cast in the rotor mounts.

[Frenchfrog]

 5.8mm is the minimum thickness.I've used ones that were thinner without any issues but....