Glazed discs?

[dbldutch02]

My front discs are a bit glazed, affecting braking.

Pads and discs still have plenty of meat on them so I'd like to save them if I can - is this possible?

My inclination is to scuff the discs and pads with some 800grit wet and dry, lube up the calipers and see what happens - feedback please!

Kevin

**edit** How do I prevent it happening again? I don't think I'm too gentle or too harsh with the brakes, but I'm a noob so could be wrong. Could the pads be time expired?

 

[Motogiro]

Try to keep your pads organized so that they go back to the location they came from.
800 grit is much too fine. Use some 220 wet or dry sand paper if you're going to wet sand them. Sand in a crosshatch manner. The pads can be cleaned up by laying a piece of 150 grit sand paper on a very flat surface and laying the pad face down on the paper and again a crosshatch motion just enough to clean off the glaze.

After reassembly there will be a need to reseat the pads to the disc so you will have very little braking. Be cautious and go easy on the brakes at first or you'll reglaze them.

 

[FinalImpact]

Can you give some details on how this impacts braking? What does it do/not do and how it feels, etc?

How do the discs look? brown, blue, black?
Are you running the OEM pad?
Does the wheel spin freely making at least 2+ revolutions if spun by hand while nose is elevated?

Post # 30 has some rotor pics... PS - I'm kinda hard on brakes --> Rotor pics here...

A quick how too on brake bleeding. Air in the lines keeps the pads/pistons from retracting and they drag. --->> Brake Bleeding 101

 

[dbldutch02]

Can you give some details on how this impacts braking? What does it do/not do and how it feels, etc?

How do the discs look? brown, blue, black?
Are you running the OEM pad?
Does the wheel spin freely making at least 2+ revolutions if spun by hand while nose is elevated?

Post # 30 has some rotor pics... PS - I'm kinda hard on brakes --> Rotor pics here...

A quick how too on brake bleeding. Air in the lines keeps the pads/pistons from retracting and they drag. --->> Brake Bleeding 101

The brakes are just weaker than they were, not catastrophically, but weaker than comfortable. Still perfectly linear though, and the wheel spins freely enough, and they are bled properly (they weren't when I got the bike)

The discs are more black than anything else, no sign of overheating - does this mean I'm too gentle on them? I'll snap a pic tomorrow.

Time to clear some space in the workshop methinks

 

[FinalImpact]

Its sometimes hard to tell blues and blacks apart. Are they OEM pads? If your style is to perhaps just ease on the brakes and glide to a stop using lots of rolling distance, well yes - you might have gentle touch that leads to buildup.

If thats how you ride, you might need to change hardware for your style using a different compound or the condition will simply repeat in cycles.

- In short, applying low braking pressures can cause pad material (binders/glues, resins) to transfer to the rotor making it glaze (usually brown in nature). Often times glazed pads tend to chatter but not always.
- It is heat from friction that burns it away keeping the rotors clean. Well that and the friction materials.

Options: change the pad compound to something softer that bites sooner without the need for high temperatures. The trade off can be brake fade when hot. << Not desirable IMO!
OR - make a mental note to brake harder a couple times a week to burn off the buildup on the rotors.

This is just me, but sanding parts seems like a temporary solution until something changes....

Lastly - When bleeding, use only pressure bleeding method during the final stages (no vacuum bleeding) and just before finishing up, hold pressure in the system and tap upwards on the caliper piston area to dislodge trapped air. Crack the bleeder and set it free. It really helps make the action firmer. Its in the link I posted.

 

[FZSexy]

i have the same problem but it really wasn't so bad once i got it off the bike and took a good look. i just put it back on, and its fine

 

[Motogiro]

i have the same problem but it really wasn't so bad once i got it off the bike and took a good look. i just put it back on, and its fine

You had to post that!

I'll meet you at at Randy's

 

[Motogiro]

Also check your brake lines for expansion. If there is a damaged brake line allowing it to expand there will be less pressure to the calipers. Many experience this more in hotter weather with rubber brake lines and switch over to steel braided type brake lines.

 

[FinalImpact]

You had to post that!

I'll meet you at at Randy's

On my way.... ^^^ lol