More dodgy brakes?

[bex]

So I had new brake discs on warranty a few months back, I think they came through a couple of weeks after Arrow Mill.

Anyway, I'm almost convinced they've started to go juddery again, only at low speeds so far when slowing to a stop. No where near as bad as before where I nearly ended up over the handlebars more often than I care to remember, but its still there. I'm hoping its just my imagination, but sadly I don't think so. I know a bit of judder is common under hard braking, but this is regular braking coming up to traffic lights type thing.

What the hell can it be? The new discs were fine when I got them and I've only noticed this in the last 7 days or so. Its had new master cylinder, front tyre, brakes pads and new discs.

I'm out of ideas. I'm also getting pissed off...:worried:

[Char]

Oh hello your having one of those days to

[bex]

haha so I see, hello! :)

[Rally]

Time for a trade in Bex!

It wouldn't be a surprise to find that the new discs have gone the same way as the original ones. :thumbsdown:

[bex]

Guess not, why would it be happening though?

Trade in for what lol? Why should I have to trade in and loose moolah when the ****er is faulty?

[Rally]

Maybe a bad batch of discs, possibly poor quality at a price, or maybe you were just so damned aggressive on them down the mountain! :D

[J.P]

Could well be another set from a bad batch if they've gone so quickly

[bex]

Oh well, I've booked in to have them looked at. That and my loose sidestand that wont ever stay tightened. Grrr.

[bex]

or maybe you were just so damned aggressive on them down the mountain! :D

'Ebby' doesnt brake! :chuckle:

[Funkatronic]

its starting to look like this is common issue wih these (albie you and one other newer shape monster all with same problem)

could it be that your pads are contacting the discs even with brakes released making the discs v hot and warp over time

does the wheel spin freely when its on a stand?

[Rally]

'Ebby' doesnt brake! :chuckle:

It would seem that we are back to 'EBBY' again then! For those not aware what it stands for, it's 'ENGINE BRAKING BEX .................

[J.P]

Is the extra 'Y' then for 'Yipeeeeeeee' ?

[bex]

No silly!

Its for Engine Breaking Bex Yeeeeeeeeeeeehaaaaaaaaaaaaaaaw ! :chuckle:

Ally, yeh spins fine, they weren't warped last time, something funny with surface abrasion was the best diagnosis we could come up with. Very strange

[Nickj]

The disc surface does change with use, it becomes harder and a bit rougher hence the bed in time. It's all in the crystaline structure of the steel and temperature changes through breaking. If the disc is flat and it's juddering then it's often the changes are patchy across the swept surface.
?? Might be because the discs have a high iron content and sometimes you get that little rusty patch under the pads, this will break up the surfacing a little.
What I used to do (did on my current 750) was pull the discs and run a disc sander over it to knock off the surface, reassemble and then find a good straight to bed the rotors in. You get up to a reasonable speed (60 plus) and then stop ..fast. Wait for the disc to cool then do it again. You are deliberately trying to get the disc surface VERY hot then let it cool off. Letting it cool off is really critical
First run the braking feels really weak, second its a bit better.. One or two more runs and it suddenly flips to two finger use levels.

[Stuart42]

[QUOTE=bex;403335]No silly!

Its for Engine Breaking Bex Yeeeeeeeeeeeehaaaaaaaaaaaaaaaw ! :chuckle:

There we go with the Yeehaaaawing again.

Anything from Chas & Dave to The Business and flying down the mountain.

I think Bex is a frustrated cowgirl. Mind you she does go on about tipping them a lot.

[Gordon H]

I can see Castle Combe is gonna be a hoot tomorrow.......

[bex]

Cow tipping, thats an everyday sport at home, dont mock it!

[Gordon H]

Cow tipping, thats an everyday sport at home, dont mock it!

No it isn't - you're just asking us to subscribe to a widely held stereotype image of Ireland...... you'll be trying to get us to believe that everyone drinks Guinness, says "top of the morning" and believes in leprachauns.....


oh, hang on......

[bex]

Actually 'top of the morning' is more a southern thing, but the rest is pretty accurate :running:

[Gordon H]

This is a long shot but might be worth considering - I remember you said that you had a hell of a job getting the discs off the first time round - I have a come across something similar on cars with distored wheel hubs - the wheel hub casting may not be 100% true where the discs are bolted on. If there is a distortion on the discs when they are secured to the wheel it may eventually (after a few miles) be enough to distort the discs and give you the juddering effect. The pads and discs would appear to be ok when checked...... It may not apply to bike wheels (don't see why not) but have come across it with cars....... dunno, but if everythine else checks out.......

[Rally]

I can see Castle Combe is gonna be a hoot tomorrow.......

It's 26 degrees on my thermometer today and tomorrow is mean't to be even hotter! I am going to take the car so we have a Gazebo to shelter under with a few seats. Shorts and tee shirts I think. :eyepopping:

Actually 'top of the morning' is more a southern thing, but the rest is pretty accurate :running:

For sure, for sure Bex. I'll pop a whip and cowboy hat in the car for you, in the hope you do make it tomorrow! :biggrin:

[utopia]

I have similar issues on my M750. I've had advisories on it for the last three mot tests, and it seems to be getting worse. The discs run true well within the tolerance limits, bobbins have been cleaned out, calipers overhauled etc. I did gently abrade the surfaces with wet and dry, which may have resulted in some temporary improvement, but it was minimal and didn't last very long.
I rely a lot on engine braking too. Most of the time my braking is just a gentle, one-fingered affair.
However, I was using the brakes a little more aggressively at the Mallory trackday, and I did think that the juddering had reduced a little afterwards.
I'm wondering if there is something going on whereby constant gentle braking is causing some sort of uneven change in the disc surface which causes the problem.
I think there is perhaps a lot of sense in what Nick says, and my plan now is to clean up the discs with wet and dry again, and then to go through the heat cycling/tempering process that he suggests, followed by a change in braking policy whereby from time to time I brake much more aggressively, to try to keep the disc surfaces in good fettle.
Maybe there is something to be said for removing one of the front discs, so the other one has to work harder and is therefore operating in its preferred range, rather than being underutilised as is currently the case.

[gary tompkins]

Pads will glaze due to lack of use which can lead to juddering

I don't think this is the cause of Bex problem though

[rac3r]

Could it be something to do with the wheel?

[bex]

Yet another new set of discs and pads coming my way. And a new seat to boot, since the surface has gone all worn and nasty.

All on warranty. Thank you very much MotoRapido.

[J.P]

You're just too 'intense' for the bike Bex.

[bex]

If only! :rolleyes:

[Gadget]

I had horrible judders after my last service. After a couple of hundred miles I switched pads to Ferodo as I could not get Carbone Lorraine's. The problem went away for about 4k.
Now I am beginning to get the judder again at low speed and gentle braking...

New disks soon I think.

[bex]

Royal pain in the ass huh? I think I've done just over 2k on my current set.

[Gadget]

I only get the judder if I am riding particularly slowly or have to be careful
But not in the wet or when I am being enthusiastic.
Go figure.
But yes. a pita.