Better rear brake shoes (drum brake)

Discussion in 'The Garage' started by scott s, Feb 11, 2011.

  1. scott s

    scott s XS650 Junkie

    Is anyone having issues with Mikes rear shoes?

    We have them on three different bikes and they just won't grab. The worn out sets we took off of two bikes were able to lock the rear wheel up, while the new shoes seem too soft or slick or something.

    We sanded the drum with 800 grit, the shoes are installed and adjusted correctly, etc.

    Where can I get some shoes that have more "bite" in them?
     
  2. jamesgs4

    jamesgs4 fuck this, let's ride!

    Did you try the yamaha dealer?
     
  3. xjwmx

    xjwmx XS650 Guru

    I got them from a dealer because it was kind of an emergency...They were ebc brand, and work well.

    Note: the rears will lock a lot more readily if you're applying the front as well;; just to make sure you're comparing old and new rear shoes the same way....
     
    Last edited: Feb 11, 2011
  4. roadcall

    roadcall XS650 Addict

    I prefer "DP Brakes". A lot of people have not heard of them. They are supplied by Parts Unlimited. Your local dealer that buys from PU can order them. I always had a lot of brake squeal from EBC. But a lot of people have not. DP has a higher carbon content, and never any squeal. Just MY opinion.
     
  5. The fact that the old shoes continue to work well and the new one doesn't leads me to think that [1]somehow some grease or oil got on the shoe surface or [2] the shoes got "glazed" right after install, or [3] they were defective from the beginning. One thing you could try is sand the surface of the shoes with medium grade sandpaper....just enough to remove the top layer of friction material. Also, check to see their isn't excessive lube on the shoe cam or anywhere else that could possibly get into the shoes when hot.
    Good luck, guys!
     
  6. tonyc

    tonyc XS650 Guru

    Mike Morris 650 Central can get you quality brakes. Tony C
     
  7. gggGary

    gggGary Fiddle Futzer extraordinaire

    are the shoes contacting all across their arc? or just a t the ends or middle? Detail oriented shops will turn new shoes to match the drum diameter.

    From: http://www.vintagebrake.com/tips.htm

    DRUM BRAKE TIPS
    Carefully inspect drum surface for grooves (obvious), crown (not so obvious), out of round and high-low spots (dial indicator). Crown often occurs with riveted linings. High-low spots commonly result when relacing hubs. There is no substitute for a freshly turned drum for premium friction materials to bed-in against. It's like putting a new piston in an old bore-never as good as with a fresh bore and hone. And you should inspect drum surface with the same critical eye. Tolerance: .002 to .004”" any dimension. Up to .010” out-of-round may be tolerated.

    If you are re-riveting new linings yourself, DO NOT drill out the rivets. Chisel off the peened end and drive the rivet out.

    Materials currently available far exceed those previously available. Reline your shoes with a current premium compound

    Keep in mind the low unit pressures required for mechanically operated drum brakes. Most linings require the higher unit pressures available hydraulically.

    Very few modern materials are compatible with pressed steel drums.

    Lay back leading edge of leading shoes in 1/2 inch increments to minimize initial "bite" if brake is too "grabby", especially when hot.

    The expanded metal used to cover scoops is typically 15% to 23% open area. Replace them with stainless steel screens with 50% to 60% open area, tripling air flow.

    Use sealed wheel bearings --grease vapor can contaminate linings. Once contaminated, they never recover.

    .Lubricate backing plate components SPARINGLY with a 500F. + degree grease, such as Sta-Lube Sta-Plex Extreme Pressure, available at NAPA. Liberally lube parts and assemble. Disassemble and carefully remove all excess grease.

    Check to see how far the backplate extends into the drum. Too far in and the sides of the shoes drag on the hub, creating excessive heat. Epoxy a shim to the inside of the backplate. Not far enough, and a ridge forms where there is no contact. Bend backplate or remove material to correct.

    Worn pivot shafts cause uneven actuation. Rebush if necessary.

    If a stay is used, make sure it does not cock the backplate.

    Always apply brake when tightening axle.

    If you want to arc the linings yourself, and have access to a lathe, first mount the relined shoes on the backing plate. Turn on the lathe (300-350rpm) to .020" under drum I.D. in .010" cuts.

     

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