Author Topic: SFC front disc play  (Read 673 times)

Offline ngiles

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SFC front disc play
« on: February 11, 2019, 10:11 »
Hi

New to me SFC1000 has a lot of play in the discs around the bobbins (as I believe they're called) - I'd say nearly a 1mm both ways laterally and 1mm in total fore and aft in a rotational sense.  The result of this is a rattley kind of disc and a very distinct sense of a knock/click when braking.  Not good - so what are my options:

1. New bobbins?
2. New discs ?
3. New webs (the bit connected to the hub)?

CHeers, Nick

« Last Edit: February 11, 2019, 10:46 by ngiles »

Online maurice turner

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Re: SFC front disc play
« Reply #1 on: February 11, 2019, 11:14 »
New bike  ;)
Thats what those original floaters are like Nick!!
81 Jota*7604*

Offline breganzane

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Re: SFC front disc play
« Reply #2 on: February 11, 2019, 11:28 »
New bike  ;)
Thats what those original floaters are like Nick!!

Not really, the fore-aft movement suggests they are somewhat jatz crackered.  The aluminium carrier wears and is not available seperately, but slightly oversize bobbins are available and you just need a friendly machinist (or even an unfriendly but co-operative one) to bore out both disk and carrier in one go.  The replacement bobbins I got had a wave washer and circlip which also takes out the side to side rattle but allows movement as designed.  Takes away a little character but works well and doesn't wear out so fast.  The bobbins I got were from a mob called France Equipment but it's a decade or more ago now.
Various 120, 180 and 360 Laverdas - and a single.

Offline Laverdalothar

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Re: SFC front disc play
« Reply #3 on: February 11, 2019, 16:29 »
not completely correct: the alloy carrier was available (but in a terrible brown instead of gold color...) from Volker (Volki here) some time ago. Not sure if they are still available, but they were a direct replacement to the original ones. Mostly the disks are still OK, but as Steve correctly said, the carriers are made out of to soft/thin alloy. It is not for nothing that they stamped "Track use only" on them... (wonder how they passed the germany TV homologation...)

Drilling out the holes with new bobins is one way to go, but Spiegler f.e. refused to do that on these carriers, as a) the material was still to soft and b) it would have taken away to much material, which in return would have left to less material to cope with the forces under heavy braking. But maybe they just wanted to sell new discs - who knows...

Spiegler in Germany builds new ones according to specs you send them. They have done a few in the past (I had a collective order roughly 5 years ago or so where I ordered I think 30 Units; the last ones were sold though 3 years ago...). https://www.laverdaforum.com/forum/index.php/topic,81242.0.html
750 SF(0) 1971 #9934 *sold*
1000 SFC Classic 1989 #3367 *sold*
1000 SFC 1985 #2934 currently under restoration
1000 SFC Preproduction bike 1985 #0001 *sold*
1200 Jota 1981 #7474
750 S-Formula 2000 #1602
1000 Motoplast - currently under construction

Offline Paul Marx

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Re: SFC front disc play
« Reply #4 on: February 11, 2019, 16:48 »
France Equipement don't seem to do oversize buttons anymore.
Doesn't Ralph at Motalia do them?

Paul

Offline Volki

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Re: SFC front disc play
« Reply #5 on: February 11, 2019, 16:48 »
yes i have the carrier still in stock!!
Volki

Offline Ventodue

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Re: SFC front disc play
« Reply #6 on: February 11, 2019, 18:03 »
Which country you in, Nick?  (And please add it to your profile ...  :D)

In the past, Red has done the work in Oz ... ('all rights of author preserved'  :P)



And in the UK, Roy Thursby



But if as Paul says, France Equipment ain't doing the bobbins no more, I don't know where you'd go ...  This was the last time I got hold of a bunch - 2008, from the date of the photo.




« Last Edit: February 11, 2019, 18:07 by Ventodue »

Offline andre g

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Re: SFC front disc play
« Reply #7 on: February 11, 2019, 18:08 »
Years ago Spiegler had some thin corrugated washers which worked like springs. Those could be inserted between the bobbins and the disk and stopped the play.
I do not know whether those washers are available anywhere today.
You can see the washers in the pictures of Ventodue.
Andre

Offline Grant

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Re: SFC front disc play
« Reply #8 on: February 11, 2019, 18:23 »
Look for wave washers.
They come in a wide range of sizes and thicknesses.
They will not stop fore and aft movement but will stop sideways rattle.
www.clublaverda.com
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Offline breganzane

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Re: SFC front disc play
« Reply #9 on: February 11, 2019, 20:28 »
not completely correct: the alloy carrier was available...
There you go, didn't know that, although the ones shown by Volki are not the same pattern as the originals.

Quote
Drilling out the holes with new bobins is one way to go, but Spiegler f.e. refused to do that on these carriers, as a) the material was still to soft and b) it would have taken away to much material, which in return would have left to less material to cope with the forces under heavy braking. But maybe they just wanted to sell new discs - who knows...

From memory the boring operation was only 0.6mm or so, since half the wear also occurred on the original (anodised aluminium) bobbins.  I'd say it was easier and more profitable to just sell new disks (also perhaps less legal problems).  The France Equipment bobbins were stainless rather than ally, my disks show no rattle quite some years and km later.

Quote from: Ventodue
But if as Paul says, France Equipment ain't doing the bobbins no more, I don't know where you'd go ...  This was the last time I got hold of a bunch - 2008, from the date of the photo.
Hey Craig, 22 of those ended up on my disks, thanks again! :D
If the bobbins aren't available separately it would be uneconomic to pay someone to make them in a small batch - new disks would certainly be cheaper.  A couple of folks have been making proper replica disks which look exactly as per the originals, Menani in Italy rings a bell, and someone in the UK, perhaps the Roy Thursby mentioned?
Various 120, 180 and 360 Laverdas - and a single.

Offline redax5

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Re: SFC front disc play
« Reply #10 on: February 11, 2019, 20:47 »
found the France Equipment bobbins expensive so we make our own these days, simple CNC program
don't believe I have a full set left in stock at the moment but that can be sorted within 7 days

probably fixed 6 sets of discs by now all told


Redax Drilling Consultants, confirmed Laverda tragic's
near Brisbane, Australia

Offline KERMIT1200

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Re: SFC front disc play
« Reply #11 on: February 11, 2019, 20:57 »
Hi Nick,
 Try this company UK ,used them a few times.

    http://www.blackshadow-uk.co.uk/index.html

Andy

   

Offline Clumber981

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Re: SFC front disc play
« Reply #12 on: February 11, 2019, 21:08 »
The main trouble with lateral play is that the original wave washers loose their set and go flat.. when i removed mine from original discs they looked flat.  Needs a bit of searching to get correct OD and ID  on the washers but i found some dirt cheap on Ebay . Came from China in less than 10 days!    Problem solved.

There was no wear on my bobbins but original spec had too much clearance between bobbin and disc carrier  and this (together with too soft material) leads to the wearing some discs.

Roy Theresby in UK only does the 280mm floaters as standard  AFAIK.

I got a set of 300mm discs from Bevel heaven in the states.  The owner managed to persuade Brembo to make a new batch with better carrier material and (modern) steel discs .  Dont know if he has any left.

Offline henrywillms

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Re: SFC front disc play
« Reply #13 on: February 11, 2019, 23:33 »
If you are in North America,  Wolfgang had the oversize   bobbins....  not sure if he still does.

Offline Dellortoman

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Re: SFC front disc play
« Reply #14 on: February 11, 2019, 23:41 »
Which country you in, Nick?  (And please add it to your profile ...  :D)

He's in Australia. Can't you tell from his accent?

BTW, it does say Sydney in his profile. While there is a Sydney (and a Melbourne) in Florida, I reckon it's more likely that he's referring to the Aussie one.  :D
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