GS12 Fornt end knock when braking

[Deleted account 211025001]

When braking on my GS12 (ABS Servo), if I grab a 'quick' handful and then release quickly there is a very pronounced 'knock' from the front end, as if the head bearings are loose.

I have checked the head bearings and there appears to be no play there.

Do they 'all do that sir', is it a function of the ABS/floating discs/unconventional front end?

Cheers
Andres

 

[Engineer]

It might be the 'float' in your front discs - hold either side of the front disc firmly and try to rotate it back and forth - you can often feel a small about of play - the knock may be caused by the 'play' being taken up when you brake. This is the case with the Brembos on my Ducati - it is perfectly normal.

 

[Deleted account 211025001]

It might be the 'float' in your front discs - hold either side of the front disc firmly and try to rotate it back and forth - <snip>

Yup, I know what you mean - my old bike had floating discs and you could hold the bike at a standstill on the front brake and by rocking back and forth feel a distinct click as the floating discs took up the play.

However this is not the case with my bike. I've also done as you suggested but can not get the discs to move

I'm getting worried now - does nobody else experiance the same knock?

Andres

 

[iletts]

had similar symptoms on my 1150, nothing at all obvious, dealer diagnosed duff front shock. I should have (but didn't) asked what exactly was wrong, but it was changed under warranty.

 

[skywalker]

When braking on my GS12 (ABS Servo), if I grab a 'quick' handful and then release quickly there is a very pronounced 'knock' from the front end, as if the head bearings are loose.

I have checked the head bearings and there appears to be no play there.


Cheers
Andres

Have you got a new model that we don't know about?
Its more than likely the pads rattling back and forth in the calipars.Give them time - they'll soon get sludged up and stop rattling

 

[John Armstrong]

Re: Re: GS12 Fornt end knock when braking

Have you got a new model that we don't know about?
Its more than likely the pads rattling back and forth in the calipars.Give them time - they'll soon get sludged up and stop rattling

Err he's putting the brakes on so why would the pads rattle Unless they're just about to fall out

AFAIK the forks are dry and only have sliders in them. As I'm running in mine at the moment and trying to take it easy I've not yet tested the front ABS, but I do have some recollection of a minor clunk either when the brakes go on or off. But I can't remember which, sorry.

 

[Deleted account 211025001]

Re: Re: GS12 Fornt end knock when braking

Have you got a new model that we don't know about?
Its more than likely the pads rattling back and forth in the calipars.Give them time - they'll soon get sludged up and stop rattling

GS1200

Mmm, I did wonder about that but there is no movement when, with the wheel off the ground and the brake on, you try to rotate the wheel which I presume there would be if that were the case?

Yours confused
Andres

 

[Deleted account 211025001]

As nobody has come on and said 'they all do that sir' I'm assuming there must be something amiss. It's a very dfinite 'clunk' so I'll raise it at me first service (still running in at the mo.)

Thanks for all the suggestions guys - I'll report back after the service.

Cheers
Andres

 

[John Armstrong]

Whens the service getting done?

 

[Taipan]

Chuffin' 'eck Andres, you broke it already!
TBH mate with all the rumours about the servo brakes on these bikes, I wouldn't take any chances and just back it for them to sort out.

 

[GSmonkey]

Mine doesn't do that...even when the ABS kicks in.

 

[Deleted account 211025001]

Mmmmmmm....... all the recent comments have served to make me even more nervous about it! I've only 300 miles on the bike so far so the first service is a week or two off yet.

Think I'll give Pidcocks a ring on Monday and get them to have a look

Thanks again!
Andres

FWIW I don't think it has anything to do with the ABS, it's a very definite mechanical clonk caused by play somewhere.

 

[Stig]

Never Fear.. Stig is Here!!!!

Mine DOES IT... and the Two Demos i rode DID ALSO...

Ive done nearly 5k on it so far... it still does it if i grab "quick n hard" ... but I don't worry about it.... and neither should you lot !!

As mentioned further up... it prob float

 

[Deleted account 211025001]

Never Fear.. Stig is Here!!!!

Mine DOES IT... and the Two Demos i rode DID ALSO...

<snip>

Stig - thank you!!

That was the answer I was after - I will still raise it at the first service just to make sure.

Andres

 

[Guzzler]

I'm gonna take a guess that it might be the telelever ball joint. It might be loose, and need to be re-torqued.

I had the same issue on my 1150GS, after the telelever was replaced. The tech didn't put any loctite on the nut and it slowly loosened up. Had to fabricate some tools to tighten it up properly (after I put on the proper loctite).

 

[ELIMINATOR]

Mine does it as well. When riding at walking pace, grab a handful, more of a thud as the pistons hammer into the disc. I put it down to the power of the servo????? Tried it quicker, but the sound of my arse clenching and my knuckles turning white drowned it out!

 

[Deleted account 211025001]

Well, it's had it's first service at 950 miles (Pidcocks, Nottingham).

The mechanic who was going to carry out the service had a ride and said he felt a definite clunk but had yet to ride a GS12 before so would investigate.

When the bike was collected I was told that they all did it and that they could find no fault with it so I went away happy.

However, just had a go on a 1150 the other day and it didn't do it at all, very solid front end......mmmmmmmm. Mind you it didn't have ABS so maybe the clonk is a function of this

Anyway, I've now gone back to being a bit unsure again so....... I think the only solution is to go back for a ride on another of Pidcocks GS12's and see for myself

I'll keep peeps up to date.

Andres