Fix Squealing Mountain Bike Brakes

Mountain bike disc brake noise can be really annoying.  Luckily, it isn’t that hard to fix with just a few basic steps.

Find the Problem

The first step is to get a spray bottle of just plain water.  Spray the water on the rotors, without getting any on the caliper/pads, and then ride it down the street and test the brakes.  Did the noise go away?  If it did, you most likely have an issue (contamination) with the pads/rotors or some glaze build-up.  Disassemble the brakes, take some really fine-grit sandpaper, and do figure eights on a flat surface.  You just want to rough up the pads a little, and clean any buildup on them.  Next, get some brake cleaner, from the auto parts store (read the label to ensure it is OK for brake pads) and clean your rotors and spray the pads with the cleaner.  Now I KNOW there is at least one person who will read this that will swear up and down that all kinds of bad stuff will happen and you may even go to hell for trying such a wicked and forbidden act, but I assure you I have done this on at least six occasions with great results every time.  Your call.  I know rubbing alcohol gets the nod most of the time, but it simply doesn’t work as good in my experience (if at all).  You may have to lightly sand your rotors, as well, if you suspect glazing.  I personally never have had to sand rotors, but I know many people do.

Water Didn’t Work

You say that when you sprayed the rotors with water, it still squealed?  Very common.  Most people start replacing parts at this point, but there is an easier solution.  Take the pads off, and clean the pistons inside of the calipers, with a lint-free cloth moistened with that brake cleaner previously mentioned, and then clean the back of the pads as well.  Most likely the noise is coming from where the pads contact the pistons.

I personally skip the second part of the above paragraph.  Instead, I clean the pistons (as mentioned) and then sand off all of the paint on the back of the pads and take it down to the bare copper (or whatever).  I then use a metal cleaner, such as Brasso, and I polish the pads.  I had a really stubborn pair of pads, on my Formula Oro brakes, that this worked like a charm on.  In an extreme case, you can put the thinnest layer of anti-brake squeal (from cars) on the back of the pads or even grease.  I am talking THIN, and apply it with a razor blade.  Anyone that has ever installed a CPU on a computer build will know exactly what I am talking about.  Good luck!

How to Ship a Bike

Q: I just sold my bike on eBay and need to know how to ship it.

A: Shipping a bike can be a pain, which is why many people choose to have their LBS ship it for them.  However, having your LBS ship your bike for you can be a bigger problem and hassle than just doing it yourself, not to mention a more cost effective solution.  And you don’t have to risk negative eBay feedback from anxious buyers and slow bike shops.  Plus you can add a picture of the bike all securely packaged to your eBay listing for added value and ultimately a higher selling price.

The first step is acquiring a box.  You have two choices for this task.

1) Go to your LBS and ask them for a box as they usually have a stack from the bikes they order.  This is a free solution, but also involves hoping it fits your bike, resealing where they cut it open, and marking over the shipping labels and/or peeling them off.  Kind of a pain, but it is free.

2) Order a bike box from Uline or this one.  Sure, you have to order five or more, but they ship it right to your door and you can probably sell the others on Craigslist, use them for other bikes/moving, or start a small biz on the side shipping bikes for people to earn extra money for bike parts.

Next you need packing materials.  The frame and fork are the most important parts, so protecting them is vital.  A good, cheap solution is to use the foam that you wrap around plumbing pipes.  You can pick it up at any home improvement store and it comes in self-sealing or you can use a roll of duct tape (that you got from the dollar store) to secure it to each tube on the bike.

From there, it is simply a question of wrapping everything else you disassembled in some bubble wrap and placing it in the box and securing it with some tape.

As for shipping, it really depends on where you are shipping from and the destination.  Shipping stores are a great solution, as they will do a cost analysis for you and give you the best rate.  The alternative is to visit UPS and FEDEX’s sites for quotes and to arrange a pick-up.

Hypothetical Situation

You charge $80 for shipping on your complete bike listing on eBay and sell it.  You buy five bike boxes from Uline for $30$10 for foam, bubble wrap, and tape.  $30 shipping via UPS.  9/27/12 – At the time of this post, I shipped out a bike on eBay for $30. That is simply no longer the case. Depending on ship from and ship to, expect $60-120. Total cost = $70.  You are up $10 to apply toward your seller fees on eBay.  Extra credit you say?  You sell your remaining four boxes on Craigslist, for $5 each for another $20.  Not bad.

 

Adjusting a Rear Derailleur

Q: How do you adjust a rear derailleur to shift smoothly?

A: You can set-up and adjust a rear derailleur on a mountain bike in five easy steps.

Step #1: Begin with the B screw adjustment.  Shift into the largest rear cog (innermost) and adjust so the guide pulley on the derailleur is just clearing the sprocket on the cassette.  If it is rubbing, add tension by turning the B screw clockwise.  If the gap is too big, turn the B screw counterclockwise to close the gap.

Step #2: Shift down to the outermost (smallest cog) on the cassette and it is time to adjust the H screw adjustment.  Be sure to remove any cable tension, as it can affect the H adjustment.  If the guide pulley looks like it wants to pull the chain off onto your axle, tighten the H screw clockwise.  If it looks like it wants to rub on the next gear, loosen the H screw counterclockwise.

Step #3: Shift back into the highest gear (innermost large cog) for the L screw adjustment.  You may need to add tension back to the cable at this point, but we will adjust cable tension later.  If the guide pulley looks like it is going push the chain into the spokes, tighten the L screw clockwise.  If it wants to throw the chain down into the next gear, loosen the L screw until it is aligned with the innermost cog.

Step #4: Cable adjustment time.  Loosen the pinch bolt, at the derailleur to free all tension from the cable.  Inspect the cable for any damage and lubricate the cable if necessary.  You can remove the cable, from the housing, and pull it through a rag with some degreaser on it.  Next, pull it through a rag of your favorite lube such as TriFlow.

***Quick tip: Instead of using a crimp, to close off the end of the cable, try using some shrink tube or Gorilla glue to seal up the end in case you need to remove it again.  This saves you from cutting off length every time you need to do cable maintenance.***

With the cable tension removed, turn in the cable tension adjustment knob all the way in and then back it out two turns.  Pull all the slack out of the cable, and reattach it to the pinch bolt and clamp it down 44-60 inch-lbs.

Step 5: Final tweaking.  Shift through all gears by going up two and down one and then down two and up one several times until the shifts are smooth and snappy.  Adjust, by 1/4 turns, cable tension of any missed gears.  If it is rubbing on a larger gear, it means there is too much tension on the cable and you need to loosen the cable by turning the adjuster clockwise.  If it wants to jump down to a smaller gear, it needs more tension and you need to tighten it by turning the adjuster counterclockwise.  Once smooth, apply a drop of lube to each adjuster screw and all pivot points of the derailleur.  Now go out for a ride and celebrate!