Amnesia180

Hi All,

I've recently got myself a second hand mountain bike - Giant Terrago. It has been used only a handful of times, and was bought as a 'secondary bike', but stayed as just that - rarely being used by a keen mountain bike enthusiast.

To be honest, I bought it because my 15 year old Claude Butler had given up on me, so I decided to get a new one to commute the couple of mile trip to work each day. I saw this going relatively cheap, so picked it up.

It is such a step up from what I used to have, 27 speed gears, hydraulic disc brakes etc... It runs very smoothly, the gears change nicely (although I have found if peddaling hard it does not like to change up the gear.... but will go down).

Anyway, there is a kind of light grinding sound, almost like a whistling... I think it MIGHT be coming from the brakes area, it is intermittent and doesn't always do it.

I know this is an extremely vague question, but is there anything obvious I should check? The brakes are concealed so I can't really see them, but there doesn't seem to be any touching on the disc that would be causing the problem... Any advice is greatly appreicated :-)

ultraman6970

The discs are touching the brake pads? Open the pads a little bit , if that kind'a help the discs for sure need to be straighten up.

maybe a cracked pad?

zvez

try lifting the wheel off the ground and spinning the wheel, you should be able to hear/feel a brake pad rubbing the disc. or is it only when you apply the brakes?

Amnesia180

Thanks for the replies.

I've done a test on the front and back wheel. It's definitely the brakes. They are MPH hydraulic brakes, and are enclosed in a case, so it is very difficult to see if they are touching or not. However, I can definitely see it looks like one of the sides of the pads are definitely touching on both the front and back disc.

Are these relatively easy to adjust? I only need to move it a mm or so back in toward the brake system.

A slightly off topic question; I've heard I can't store my bike 'upright' because of the hydraulic system thats on it. Is that true? I have my bike stored on its back wheel in a bike rack...

Andrew R Stewart 

Most all disk brakes use a caliper that mounts on the frame with a couple of bolts. Usually the mounting tabs (of the caliper) have short slots to allow the caliper (and the pads within) to be repositioned side to side for pad centering.

But without photos i can't say for sure if your brakes have this adjustment feature. I'm not going to spend time searching all the brands and models of components that are asked about here so without the photo you'll have to do a better job describing the brakes or discover the design features on your own. BTW "covers" are usually easily removed for access to the working insides.

As to storage- you ride the bike with it's being up right. So i hope your brakes are designed to work with the bike in it's "in use" position. If you mean storing the bike 90* to it's in use position, like from one of it's wheels (or even upside down) I would not worry. I have never heard of a hydraulic brake that couldn't function when the bike was in every position conceivable. NOW some forks that use fluids for their damping functions are able to have the fluids drain out of the lower parts of the fork. Then any features that depend of this fluid to be i n the lower portions of the fork might not work for a few minutes when the bike if placed on the ground (after wheel hanging storage). But the fluids will return to their "in use" place in short order. Andy.

ultraman6970

Hard to tell you w/o knowing what brakes do you have, besides that looks like you can take it from here on, right??? If you dont figure it out yourself you wont learn Besides is not rocket science, there is a screwing mechanism somewhere close to the pads that when you turn it it makes the pads closer or far from the center of the caliper.

Good luck