revtothelimit - motorbike forum

OK... 2005 zx10r.

Spanking along on a private road *cough* at about 110-120 - the farmer (his road *cough* ) pulled out of a field. I grab a handful of brake, at it was like my disks were warped...lots of vibration, not much braking... I let off, grab another handful and clinch my seat with my sphincter... again.... thrrrrrrr thrrrrrrrr... again off and on... brakes worked.

After ironing out the crease in my seat... I take a look. Can see nothing.

Odd me thinks.

Try a few hard brakes from 50.... nothing but normal braking...... 80....nothing but normal braking..90......... nothing but normal braking.....120....... nothing but normal braking. Hmm.. maybe a stone or I hit a ripple in the dunno.

Using another private road.....proper smooth tarmac. Grab a handful before going into a bend.... same thrrrrrrrrrr...thrrrrrrrrrr... lots of vibration, little braking, another sphincter clenching moment.

Fuck, this is odd and really not good me thinks.

Again... stop, look, can see fuck all wrong. No sign of hot spots. So again I try loads of braking from different speeds, get the disks pretty hot. Nothing... just normal braking.

Now I have no idea.

Ever come across anything as weird as this??

Same symptoms as abs then...

Yeah, it felt pretty much like that.... but there is no abs on the bike....

Didn't you do something with the brakes not long ago, paint?

I'd have them to bits and check the pistons or that the pads aren't coming to bits.

only on big braking.??

KungFooBob wrote: Sat Aug 08, 2020 5:04 pm Didn't you do something with the brakes not long ago, paint?

I'd have them to bits and check the pistons or that the pads aren't coming to bits.

I did...yes. I have a set of pads to put in (couldn't get them when I rebuilt them) They are worn, but...

Oh well. Have them apart, maybe it needs some Brembo forged monoblocks

Dodgy knees wrote: Sat Aug 08, 2020 5:09 pm only on big braking.??

It would appear so, but not on command. ie I cant seem to make it happen at will :|

They are sintered HH pads, yes.

I had a similar thing on my ten a while back. I took out the pads and gave them a good rub with rough emery and all was fine.

All I could put it down to was,the pads had picked up something they didn't like and they were a bit glazed.

Worth a try before you go looking for anything more labour intensive!

Coming off what [mention]inewham[/mention] said, I read once, following heavy front braking and coming to a stop, don't keep front brake on, can leave itself on disc.

Sintered pads have the same material as rally paddle clutches, they leave bits of the material on the flywheel a lot. I much prefer organic pads for road use.

Wouldn't have been a bumpy road knocking the pads back.

My car does this too, badly enough that it's been to the dealer several times to no avail.

You can feel gently "thrumming" if you graze the pedal, nothing under medium braking then shuddering under harder braking.

It only seems to do it on brand new or nearly dead pads/discs. It seems weird that the problem sticks with the car rather than going when you change pads etc.

Just by coincidence I was doing work with a surrwy based supercar manufacturer when this problem first cropped up, one of their chassis guys suggested it was an alignment or stiffness (i.e. shot bushes) issue. Have you put your callipers etc. back on straight?

I’m going to strip them today and looksee

Thanks for the replies

Well I found the issue, but it's too embarrassing to admit..... Therefore let's put it down to "road fairies"

One of the pads in the wrong way round

I've done it on a car, but never a bike.

Worse....

I can't believe I didn't even notice when I stopped 3 times to look

Wreckless Rat wrote: Sun Aug 09, 2020 11:23 am Well I found the issue, but it's too embarrassing to admit..... Therefore let's put it down to "road fairies"

Well, I'll admit to one, then you can cough to yours?

My 'lack of braking' issue was the result of taking the pads out to clean them, etc.

Apparently they work better if all four, not just three, have the pads installed with friction material against the disc

Your go

wow - I'm not the only eejit!

Let's just say... calipers are normally held on with TWO bolts........

I have ordered a new set... clearly one is somewhere on the private road system.....

I suppose they are radial callipers, so not as easy to spot as on traditional callipers.

KungFooBob wrote: Sun Aug 09, 2020 11:43 am I suppose they are radial callipers, so not as easy to spot as on traditional callipers.

Yeah, that's my excuse....