73 SFC replica for sale

Paul Marx

Hero member
Location
France
Bob Heath used to race his G50 with an unpainted frame to gain a few grams.
Apparently quite a common practice in the days when bikes didn't churn out hundreds of HP.

Paul
 

piranha-bro2

Hero member
Location
Melbourne
Paul Marx said:
Bob Heath used to race his G50 with an unpainted frame to gain a few grams.
Apparently quite a common practice in the days when bikes didn't churn out hundreds of HP.

Paul

I trust he also took strong laxatives the morning of the race, shaved every hair from his body, removed his false teeth (which he had fitted to allow him to remove them on race day), didn't drink any fluids and slept in a sauna for three days prior to help rid himself of unwanted grams of body fluid ... sheesh! FFS!
 

CLEMTOG

Hero member
when I mechanicked for sidecar race teams, almost all of them were  bare metal chassis, this was (mainly and the big point) so that inspection of all areas, for cracks and defects could continually be looked at. It was my idea (when Tony Bateup was building a new chassis for Brian Houghton and the Bevan imp) that a pilot hole was drilled internally at all tube joints, to connect the innerds of them all together, then a 1/4 BSP boss was welded on near the headstock to carry a pressure gauge with another boss and a Schrader valve at the rear, the idea? simply pressurise the whole tube chassis to around 20PSI, and if a crack occurs the pressure drops. This seemed like a good idea but it didn't tell you if a brazed on bracket outside of the tube formations had cracked, or even broken off, as in the case of the rear brake pedal at the IOM in 1975? ! it dropped into the streamlining, fortunately and Brian still won the Southern 100, mainly because he was so far ahead that he was already hard to beat, there was a lot of front wheel lockups though, as the pedal linked all three wheels, and the handlebar lever and calliper was really only for scrutineering, which stipulated separate brake systems.
Then they had riveted/glued aluminium chassis, such as Seymaz, LCR etc and then carbon fibre. sometimes made by Arrows cars.
CLEM
 

Paul Marx

Hero member
Location
France
Piranha Brother 2 said:
I trust he also took strong laxatives the morning of the race, shaved every hair from his body, removed his false teeth (which he had fitted to allow him to remove them on race day), didn't drink any fluids and slept in a sauna for three days prior to help rid himself of unwanted grams of body fluid ... sheesh! FFS!

Every little bit helps when you're hustling a 45 HP machine around the Isle of Man.

Paul
 

laverdas

Hero member
For what it's worth i think cadnium plating is banned in the UK.
Bentley motors (local car plant) had to remove and dispose of all cadnium plated parts from there stores due to the toxic nature.
Regards Andy
 

MarnixSFC

Hero member
When you ask people in Breganze there is no consensus about the frame finish, but I had several unrestored frames in hands and took one to my local plater, who did a check and said it definitely was zinc plating. A friend who wanted to try cadmium plating managed to get an aerospace company to do a frame. The result wasn?t as expected and the frame is now painted silver..

I too think that they plated the frames because cracks can be quickly be detected. Drum brake SFCs often suffered cracks, supposedly because they were they were raced in endurance races to the limit, and beyond.

Marnix
 
laverdas said:
For what it's worth i think cadnium plating is banned in the UK.
Bentley motors (local car plant) had to remove and dispose of all cadnium plated parts from there stores due to the toxic nature.
Regards Andy

Cadmium wouldn't be totally banned ........ 90% of the hardware on aircraft is cad plated and so far there is no viable replacement. Cadmium has a major advantage in that consistent and smooth torquing is achieved as well as superior corrosion resistance. No other plating can offer both at this time.

Jim
 

Dellortoman

Hero member
Vince said:
I used to think Galing a frame would be great long-lasting protection but after getting my dirtbike box trailer hot dip galled it went from an easy one-hand lift and push to a full-blown backbreaker. It's insanely heavy now, but definitely no rust in the last 20 years it been in my back yard. Odd choices for a lightweight race bike.

G'day Vince,

Hot dip gal shouldn't have added a significant amount of weight. It's only a thin coating. Are there any tubular parts to the trailer chassis, such as RHS or round tube? If so, one or more of them may have filled with zinc and not drained when the thing was lifted out of the dipping tank.

I enquired about getting my bike trailer galvanised many years ago, and they said all tubular parts had to have pressure relief holes drilled in them. The explanation at the time was that the molten zinc is very hot and any sealed spaces with air in them could build up a high pressure inside. They didn't want any explosions due to gas pressure build up. However, that meant molten zinc could get in, and there's no guarantee that it'll all drain out when they lift it out of the tank. Maybe if you drill a few drain holes and get it re-dipped it'll come back lighter.

In the end I decided to paint the trailer rather than getting it galvanised. Much cheaper and easier. It's still hanging together after 40 years.
 

Vince

Hero member
The only hollow section would be where the floor was replaced, some of the old floors remained so maybe I now have a 10mm thick section of solid gal between. It got that heavy I had to add a Jinny wheel to move it. It was as I said a one hand easy lift and move before. Now its a ball breaker without the Jinny wheel. The trailer place charged me $400 about 20 years ago, I saw the results of my Dads poorly painted trailer years ago. It just disappeared with rust.
 

Laverda SF

Hero member
I agree with Marnix either a 71 or 72 SF with a SFC Fairing and Saddle, Pipes and rear sets are up to rider - Not too shabby but my ride was in much better condition ;o)
 

angonemoto

Hero member
Location
Chicago, USA
All things considered, it's a clean SF with some poor assembly and fastener choices to boot. Are we saying it's a fools errand to get this at a non replica price and refit it to a SFC spec because of the year?

I'm considering that cuz the bike is so close to where I live. I'm not sure what ignition is in there, but I can pull the cover. What other easy looks can I get from a visit to see just how much would need to be done to create a worthy replica out of it?

Fire away!
 

IAG

Hero member
Location
Chicago
angonemoto said:
All things considered, it's a clean SF with some poor assembly and fastener choices to boot. Are we saying it's a fools errand to get this at a non replica price and refit it to a SFC spec because of the year?

I'm considering that cuz the bike is so close to where I live. I'm not sure what ignition is in there, but I can pull the cover. What other easy looks can I get from a visit to see just how much would need to be done to create a worthy replica out of it?

Fire away!
My first concern is the claim that the bike is ridden once a month-Fuel lines dry w/no discoloration-fuel in the tank? Exhaust downpipes have no discoloration, either.  The bike looks like a living-room display piece. Fitting the bike to SFC spec would be costly but I agree-it's a clean SF. Go see it, ride it & let us know how nice (or not) it is! 
 

MarnixSFC

Hero member
Depends how far you choose to go.
Do you want to alter the frame to SFC spec and do same with the swingarm? The small valve engine may run very fine, but of course SFCs all had had big valve head with big carbs. The SFC parts on this bike are mostly disc brake SFC items, so not right for drum brake chassis.
All entirely up to you of course.

Can be a fine machine to ride as it is too if the engine is healthy. 

Here in Europe, the short bell mouths would indicate the engine being GT spec, but I believe the SFs that were exported to the US were fitted with an air filter, which requires short bell mouths.

Marnix
 

Laverda SF

Hero member
MarnixSFC: The SFC 750 cam is too long in duration for the street. The standard 70 SF cam works approaching 7800rpm with open mouth Dellorto 32 VHB's with 2 into 1 pipes. Say Mukini's CSV 34's maybe worth a try (Never tried it). I actually have set of them - If your interested and still be able to use a velocity stack and an air breather, Basically do the same thing as the 32 VBH's but keeps dirt outta the engine ;o)
 

Laverda SF

Hero member
$100 Canadian for the pair (Guaranteed in great shape). But you have to fabricate linkages and play with jets plus pay for shipping ;o)

VHB to PHB's: "No you can't get away. From hell's heart I stab at thee. For hates sake. I spit my last breath at thee." Mikuni CSV BS 34's !

They sell for for over $160 US a piece - Lots of part accessories available at descent prices.

Personally, I would extend the series linkage and just use a single throttle cable. Then of course you require a vacuum hose to each carb from the cross over manifold tube or feed the vacuum separate to each carb without a manifold tube.

Kinda off topic it's a Paul thing ;o)

 

ducky

New member
Spoke to the seller a couple of months ago and seemed a good guy. He also has the SFC with 5 original miles, asking north of $150k, and a nice MHR Ducati as well as others from the era.
 
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