Juddering disc brakes

"Paul Boyd" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Is that oil contamination? I'm new to this disc brake malarkey! It's
entirely possible that the disc (the back one) might have got slightly
misted when I sprayed the chain.

If that's the case, is it just a case of cleaning everything with IPA, or
are the (sintered) pads scrap?

One thing you don't do with disk brakes, is spray WD or other oily things
all over the shop. The thing to do is to take the disk off, clean it
(Fenwicks is good), and then take the pads out and blow torch them briefly.
Worked a treat on a set of Magura Louises I had which went from bugger all
breaking ability to stupendous.

Doki said the following on 14/07/2006 14:20:

Quoted message said:

One thing you don't do with disk brakes, is spray WD or other oily things
all over the shop.

I know, I know! I was on autopilot, and my finger had already gained
sufficient downward momentum on the trigger to ignore my brain saying
"STOP!".

Quoted message said:

The thing to do is to take the disk off, clean it
(Fenwicks is good), and then take the pads out and blow torch them briefly.
Worked a treat on a set of Magura Louises I had which went from bugger all
breaking ability to stupendous.

Hadn't thought of the blow torch idea. That should work OK. (I guess
not on resin pads though!!!!!)

--
Paul Boyd
http://www.paul-boyd.co.uk/

in message <[email hidden]>, Paul

Boyd (') said:

Is that oil contamination?

Most likely. It's contamination with /something/. Disk pads can't be
cleaned; if cleaning the disks with alcohol (e.g. meths) doesn't solve
the problem, you will need to buy new pads.

Quoted message said:

I'm new to this disc brake malarkey! It's
entirely possible that the disc (the back one) might have got slightly
misted when I sprayed the chain.

Yup. This is why disks are not a practical idea unless you /really/ need
them (which, if you're riding on the road, you don't).

Quoted message said:

If that's the case, is it just a case of cleaning everything with IPA,
or are the (sintered) pads scrap?

Probably scrap but you might get lucky.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

;; Good grief, I can remember when England won the Ashes.

On 14/07/2006 17:55, Simon Brooke said,

Quoted message said:

Most likely. It's contamination with /something/. Disk pads can't be
cleaned; if cleaning the disks with alcohol (e.g. meths) doesn't solve
the problem, you will need to buy new pads.

Rotors cleaned with hot soapy water, then with IPA. Pads baked in an
oven at about 250degC for an hour then scuffed with coarse wet'n'dry.
Quick test ride - bugger!!!!!!!

Quoted message said:

Yup. This is why disks are not a practical idea unless you /really/ need
them (which, if you're riding on the road, you don't).

This bike was bought specifically for off-road use, where they certainly
work well when the rest of the bike is plastered in mud. I'm trying to
regain my lost mountain bike skills from when I was 15 years younger,
and living within sight of the Mendips that has to be worthwhile :-)

Quoted message said:

Probably scrap but you might get lucky.

Fat chance! Off to LBS tomorrow...

--
Paul Boyd
http://www.paul-boyd.co.uk/

in message <[email hidden]>, Paul

Boyd (') said:

On 14/07/2006 17:55, Simon Brooke said,

Quoted message said:

Most likely. It's contamination with /something/. Disk pads can't be
cleaned; if cleaning the disks with alcohol (e.g. meths) doesn't solve
the problem, you will need to buy new pads.

Rotors cleaned with hot soapy water, then with IPA. Pads baked in an
oven at about 250degC for an hour then scuffed with coarse wet'n'dry.
Quick test ride - bugger!!!!!!!

Quoted message said:

Yup. This is why disks are not a practical idea unless you /really/
need them (which, if you're riding on the road, you don't).

This bike was bought specifically for off-road use, where they
certainly work well when the rest of the bike is plastered in mud.

Yes, they do. For really dirty muddy mountain bike stuff they're
definitely the best option. We just get a lot of people who /assume/
that disk brakes are the best thing for their commuter bike, where
normally they're not!

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

((DoctorWho)ChristopherEccleston).act();
uk.co.bbc.TypecastException: actor does not want to be typecast.
[adapted from autofile on /., 31/03/05]

On 15/07/2006 12:06, Simon Brooke said,

Quoted message said:

Yes, they do. For really dirty muddy mountain bike stuff they're
definitely the best option. We just get a lot of people who /assume/
that disk brakes are the best thing for their commuter bike, where
normally they're not!

I would like them on my commuter/tourer, but only for pose value :-) My
cantis work well in all conditions on that bike.

Anyway, one trip to my LBS and £20 lighter, I have nice smooth rear
brakes again. I did clean the rotor again before putting the new pads
on. Just got to bed them in now. Aren't disc pads easy to change
compared to brake blocks? Pop out the old, a quick clean around and pop
in the new. No fiddling about re-adjusting anything - they just work.

--
Paul Boyd
http://www.paul-boyd.co.uk/