Brakes stopping power just gone

andy83

Have giant MPH brakes on my bike but all of a sudden it seems like they have lost all stopping power

also after only a few rides im finding myself having to turn the adjusters as the lever arms just tend to start moving inwards into the handlebars

There is also a little like buzzing sound when i do apply the brakes hard. the discs are in fairly decent nick. WOuld it be a case of bleeding the breaks? and if so what is the best kit to be able to do this, have seen you can buy them but others say just make your own. Brakes were second hand but rotors dont seem too warped, bent them out a little myself and seems better. ever since ive had them never gave me superb stopping power but their my first disc brakes so not sure what to expect. could a good bleed sort em out?

thanks

drewp2008

A bleed might but it could be a host of other things. lbs is your best bet.

Might be that you've cooked the fluid though by the sounds of it. just an educated guess but might not be.

Noel PT

Have you tried cleaning your discs with, disc cleaner?

you might just have a bit of oil or silicone spray on them.

Just an idea....

supersonic

Giant 1st gen MPH brakes are an closed system, so you have no automatic pad wear adjust. So as pads wear, you need to move the adjuster on. Check pads.

xtreem

I agree with supersonic. Move the pads closer to the rotors.

andy83

drewp2008 wrote:

A bleed might but it could be a host of other things. lbs is your best bet.

Might be that you've cooked the fluid though by the sounds of it. just an educated guess but might not be.

what you mean by cooked t fluid?

will give them a good clean aswell

supersonic that does sound right,when i adjust they seem fine, just an ass having to adjust all the time, might save for some new ones, but need new ones first?

nicklouse

the Buzzing noise is normal. just the noise of the holes in the disc going through the pads.

and yes you do need to adjust the brakes as the pads wear.

andy83

cheers nick
all new to me as never had discs before

Bmjboy

Yep, just to confirm, buzzing is completly normal, as if you have stock rotors as I do, they have drilled holes, its simply the holes whizzing through the pads.

As mentioned, pads wear down and you need to close the gap between the pad and rotor to give the lever bite earlier.

One option that you may have done is got some lube/oil on the rotors, WD40, GT85 anything like that will dramatically ruin braking power (as I have just stupidly found out after long time of avoiding doing that!!)

You'll be hard pushed to cook your brakes on that, Im a heavy bloke and belt down some big hills braking very hard, and Ive NEVER cooked my brakes yet (although Im sure it doest happen)

This file will gtive you a better understanding of the brakes:
http://www.wrower.pl/instrukcje/Giant/2001-MPH-3_owners_manual.pdf

If you continue to have braking problems with the pads right up against the rotors, then I suggest new pads and possibly bleed.

-liam-

Remove the pads and clean them up as well. Mine were glazed up with dirt/oil/whatever. Gave them a rub with some sandpaper to expose a fresh surface and remove any glaze and they are good as new.