Rear Rotor Thickness

[mralex714]

What is the minimum thickness of the rear rotor for an 86 VR? Didn't see it stamped on it.

Also what would cause the brake pads wear more on the back end of the pads?

[MiCarl]

Off hand, I do not know the minimum thickness. It should be in the service manual.

 

The reason the pads are wearing unevenly is there are ruts worn into the front side of the caliper. Pads get caught in the rut and the fronts won't close. That's not good because some of the braking force is going into the rut instead of stopping the motorcycle.

 

On mine, I completely disassembled the caliper and had a welder I know fill the ruts. I had planned to file them back flat but he had a slick little air-powered belt sander and did that too.

[Prairiehammer]

What is the minimum thickness of the rear rotor for an 86 VR?

 

Minimum rear rotor thickness is 4.5mm (5mm new)

[dna9656]

See the base service manual "83 to '85, Chapter 2 Periodic Insp. and Adjustments; pages 27 and 28 in the chart states 8.5mm is NEW for both front and rear rotors. I called the dealer and I THINK they said the minimum was 5mm but I might be wrong, call your local dealer and get a confirmation. With my cheapie harbor freight sliding vernier caliper I measured 8point ?? I am skeptical of that number as the bike is an 84 with 66K miles. I don't know how they wear (the rate being fast or slow) but again I have no idea when and if the rotors have ever been changed.

[dna9656]

See the '83 to '85 Base Service Manual , Chapter 2 Periodic Insp. and Adjustments; pages 27 and 28. The chart states 8.5mm is NEW for both front and rear rotors. The minimum is not (thanks a lot Yamaha) given I have a cheapie harbor freight sliding vernier caliper; I measured 8point ?? I am skeptical of that number as the bike is an 84 with 66K miles; besides that how can the rotor be THICKER than new? Production variance? I hope not. I don't know how they wear (the rate being fast or slow) but again I have no idea when and if the rotors have ever been changed.

[Prairiehammer]

See the base service manual "83 to '85, Chapter 2 Periodic Insp. and Adjustments; pages 27 and 28 in the chart states 8.5mm is NEW for both front and rear rotors. I called the dealer and I THINK they said the minimum was 5mm but I might be wrong, call your local dealer and get a confirmation. With my cheapie harbor freight sliding vernier caliper I measured 8point ?? I am skeptical of that number as the bike is an 84 with 66K miles. I don't know how they wear (the rate being fast or slow) but again I have no idea when and if the rotors have ever been changed.

 

First of all, Doug, mralex714 asked: What is the minimum thickness of the rear rotor for an 86 VR? The correct answer is 4.5mm.

 

 

The minimum is not (thanks a lot Yamaha) given ...

 

The minimum disc (or rotor) thickness (front and rear) for a 1983-1985 is 6.5mm (0.26 inch). This information is found on page 5-4 in the paper factory manual.

[dna9656]

All the time with the details....details , details Smetails....Well he was talking about a different bike,,,, but the info is still correct as applies a whole different bike;

neener, neener, neener! So what's the minimum on a 83 to 85?

Edited February 15, 2015 by dna9656

[Prairiehammer]

The minimum disc (or rotor) thickness (front and rear) for a 1983-1985 is 6.5mm (0.26 inch). This information is found on page 5-4 in the paper factory manual.

 

So what's the minimum on a 83 to 85?

 

Hitting the Black Velvet are we, Doug?

[dna9656]

I'll never tell.

Besides why can't it be listed in the chart I cited? I know, I know it's not American/English thinking.....