Author Topic: Magnesium rear hub 750 SFC  (Read 635 times)

Offline MarnixSFC

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Re: Magnesium rear hub 750 SFC
« Reply #15 on: November 02, 2019, 09:07 »
Would like to add that despite stories about magnesium hubs falling apart, well these donít, not in the past 45 years. No need to paint them, unless for cosmetic reasons.

Marnix
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Offline Paul Marx

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Re: Magnesium rear hub 750 SFC
« Reply #16 on: November 02, 2019, 09:09 »
Paul, you need PHB not VHB!!!
Ciao, Gert

You're right.
I've got the end of my nose in my S. I've become a VHB expert.

Paul

Offline sfcpiet

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Re: Magnesium rear hub 750 SFC
« Reply #17 on: November 02, 2019, 09:20 »
Would like to add that despite stories about magnesium hubs falling apart, well these donít, not in the past 45 years. No need to paint them, unless for cosmetic reasons.

Marnix

I tend to agree.  The worst I've seen on these hubs is the damage caused by the missing spacer.  Happens all the time... ::)

Reckon corrosion from salt, etc, would be the big issue, once it sets in it will be hard to stop.  Most magnesium alloys develop natural oxidation when exposed to normal atmosphere, this goes a long way to inhibit further corrosion.  I have no issues using the Fontana magnesium hubs on the racer.  I bead-blasted them, checked for damage and painted them for peace of mind.  The hubs and brake backing plates on my Chott are also still in top condition, no worries there either.

piet
180s feel quick, 120s are...      If it ain't broke, fix it till it is.

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Offline MarnixSFC

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Re: Magnesium rear hub 750 SFC
« Reply #18 on: November 02, 2019, 10:14 »
You're right.
I've got the end of my nose in my S. I've become a VHB expert.

Paul
36mm VHBs even rarer than PHBs.  ;D
Marnix
International Laverda 750 SFC Owners Registry

Offline Uwe H.

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Re: Magnesium rear hub 750 SFC
« Reply #19 on: November 02, 2019, 11:49 »
Yes, Marnix, the 'old' magnesium hub of my SFC shows no signs to falling apart either.

For the cush drive, I had a spacer between drive and hub, which appeared to be a bit too thick.
The rubber shock absorbers were not sitting evenly in place, but sort of diagonally / in an angle.
Since I am riding much with my SFC (close to 70.000 km now), the rubber elements showed a sloping / slanting wear.
I changed to a thinner spacer, which may have been this certain amount too thin.
It worked long, but since the inside of the hub is not fully even, like a machined hub, it could well be the question in
which position one have put all together the next time (it may be, but not necessarily).
After discovering the cracked egde, I have installed a spacer with a measure between the two previous ones, for the
ease of the edges and the rubbers.

Could make sense to take the wheel out and just hold all together without rubber elements, to checking there is truly
free play...

Piet, assembling all without the spacer, I would expect the worst, to destroying the seats of the bearings as well, right?
Cheers, Uwe


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