Challenges in maintenance of MTB

Wheels of Happiness

From my experience and reading various posts in soc media there are two challenging issues:    operation of front derailleur and the the disc brakes

1.  Front derailleur -   the difficulty of fd shifting to the largest chain.   I experienced this myself.   Several actions are suggested:

     1.  Check and oil the pivot.  Dirt and astray parts could jam the mechanism

     2.  Check the cables:   the outer and the inner cable.  You can clean and oil the cables.   The dirt and  crud could jam the shifter action

     3.   The limit screw.   The outer limit screw, the hi limit screw could be loosened by 3/4 to 1 turn (or more as the case  may need it)

     4.  The barrel adjuster.    A turn or two can make the fd shift nicely

2.  The disc brake.    That is why the rim brakes (the V brake) are simpler to maintain.   The most common

      complain is squealing brake. Or failing brake

      1.  Failing brake could be caused by:

           1.  Worn out pads -  replace when the metal back is almost exposed

           2.   Worn cable -  replace

                  No more mineral oil -  add

                   Air in the system -  bleed the brake

     2.  Noisy brake

          1. Caliper not centered.   Center the caliper by sight -  lossen the mounting bolt and and try

               tightening  usual visual sight

          2.  Score in the disc -  try to sand, and or replace

          3.  Glazed brake pads -   clean with detergent, alcohol and/or sand paper

          But sometimes these may not work and the noise/squeaal reappear

          Try and try until the sound disappear

Removing squeals from disc brakes.

Wheels of Happiness

Rizal Philippines

6.29.2021

One of the factors vs disc brake, aside from high maintenance  activities and cost, is its occasional squeal, when the pads and discs are contaminated by oil and dirt.  

I consulted Mr. Mario Toledo a expert mechanic and his advice were:

1.  Clean and sand paper the disc, wipe clean with alcohol.

2.  Remove brake pads (assuming that it is still thick) and clean by rubbing together the friction material after dropping several drops of dishwashing fluid (joy)      Then sandpaper to remove the stubborn dirt or glazed material

3.   Fry the brake pads.  Pinch them together with a plier or vise grip and expose in open flame for 3 to 5 minutes until you see the contaminants evaporate.  

This work for the two bikes I tried to repair last week.  

This is a very common complaint in a page dedicated  to home repair  I hope this helps

Bedding in and/or burning in the brake pads - how to cure disc brakes squeal.

Wheels of Happiness

Rizal Philippines

4.24. 2021.

How to stop squeaking disc brakes

The growing interest in disc brakes even in road bikes should be accompanied by increasing knowledge on disc brake technology.

Other cyclists including the pro, dislike disc brake for the additional weight and more maintenance costs and processes.

One of the never ending problems in disc brakes is brake squeal.

The usual cleaning the brake pads and discs with alcohol and/or sand papering the pads and the disc, there are other things I did not get to know -  the burning in and or bedding in the  brake pads.  This must be done:

     1. When new brake pads or discs are installed;

     2.  Immediately after the cleaning of the pads and the disc

You can do the bedding in either by:

1.  Riding down a long hill with brakes engaged 75%.   You are literally burning the disc and the pads with this process

2.  Ride on a level ground using the largest rear cogs, and engaging the  brakes slightly (same 75%)  The squeak may recur but eventually as the disc and pads bed in the squeal should disappear.