Author Topic: Talking about the drumbrake 3C  (Read 65871 times)

Online maurice turner

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Re: Talking about the drumbrake 3C
« Reply #195 on: February 06, 2016, 09:32 »
Thanks Scrumpy they sure are beautiful and even better to ride I took my Aussie Drummer out today for a couple of hundred Kms back to the chap I bought her off in fact parked her out of the 38 degree heat back into the shed where she sat for 21 years as a poorly assembled and neglected classic motorcycle.
I tried to get some more information about the early history of this bike but I am afraid I can only assume her beginings.
I understand now why they introduced the linked carbies on the next generation triple as those individual cables seem to constantly need adjusting.
81 Jota*7604*

Online pf1

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Re: Talking about the drumbrake 3C
« Reply #196 on: August 27, 2016, 08:58 »
Here is drummer number 1015 for sale in Cremona, glad to see it still survives although it's been converted to discs.
You can see the frame number and the weird little breather in one of the pics and also the early upper shock mount position. It would have been the same as the Cycle magazine bike 1012 when first assembled at the factory.
There is a picture on Laverdamania of these first bikes lined up in the old factory all metallic red and all with fibreglass tanks and 3 into 1 exhausts if I remember correctly.
Anyway, get your money out €15000

http://zanimotor.it/it-it/laverda-1000-3-cilindri/a/375

http://www.kijiji.it/annunci/moto-e-scooter/cremona-annunci-castelverde/laverda-1000-3-cilindri-preserie-by-zanimotor/102094552?utm_source=wickedin&utm_medium=aggregator&utm_campaign=scooter#1
« Last Edit: August 27, 2016, 09:02 by pf1 »

Offline lavgert

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Re: Talking about the drumbrake 3C
« Reply #197 on: November 07, 2016, 08:13 »
1958 - 100 Sport
1974 - 250 Chott
1976 - 750 SFC Electronica
1977 - Sulzbacher 1000 3CL
1978 - Sulzbacher 1200 SC
1978 - Sulzbacher 1200 SC
1977 - 1200 Special (under construction)

Offline lavgert

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Re: Talking about the drumbrake 3C
« Reply #198 on: August 21, 2017, 11:44 »
... I am very happy to find this original LAVERDA press photo - a nice studio shot of a drumbrake 1000 3C - Studio Foto Vajenti Vicenza, stamped on the back. Interesting to see the ignition lock mounted to the side panel. Ciao, Gert
1958 - 100 Sport
1974 - 250 Chott
1976 - 750 SFC Electronica
1977 - Sulzbacher 1000 3CL
1978 - Sulzbacher 1200 SC
1978 - Sulzbacher 1200 SC
1977 - 1200 Special (under construction)

Offline CLEMTOG

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Re: Talking about the drumbrake 3C
« Reply #199 on: August 21, 2017, 12:26 »
that is very, very early, probably a proto, no logo on clutch and "Laverda" on bulge for engine sprocket, plus no dimple for the primary chain tensioner axle, plus loads of others, so I will stop now
Clem

Online maurice turner

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Re: Talking about the drumbrake 3C
« Reply #200 on: August 21, 2017, 12:46 »
This bike may in fact be the bike that Cor has see the starter button!!!
81 Jota*7604*

Offline Steph

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Re: Talking about the drumbrake 3C
« Reply #201 on: August 21, 2017, 19:32 »
... I am very happy to find this original LAVERDA press photo - a nice studio shot of a drumbrake 1000 3C - Studio Foto Vajenti Vicenza, stamped on the back.

Beautiful shot of a lovely bike..

 (bigthumb)

Stéphane

Offline MarnixSFC

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Re: Talking about the drumbrake 3C
« Reply #202 on: August 21, 2017, 21:22 »
Cor's prototype is the one that went to the USA. It already had the ignition switch in the usual position. Cor modified it. There is a prototype (#1012) with the ignition switch in the side panel in Sweden, former Laverda pr man Hans Blomqvist owned it.

The bike in Gert's picture is painted red though.

Marnix
International Laverda 750 SFC Owners Registry

Offline lavgert

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Re: Talking about the drumbrake 3C
« Reply #203 on: August 22, 2017, 07:42 »
... this, I think, is the swedish early 3C! Ciao, Gert
1958 - 100 Sport
1974 - 250 Chott
1976 - 750 SFC Electronica
1977 - Sulzbacher 1000 3CL
1978 - Sulzbacher 1200 SC
1978 - Sulzbacher 1200 SC
1977 - 1200 Special (under construction)

Online pf1

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Re: Talking about the drumbrake 3C
« Reply #204 on: August 22, 2017, 07:44 »
That's the 'other' duplicate 1012 isn't it?
The Cycle World magazine test bike being 1012 also, unless that particular one was brought back from the USA/Canada and refitted with all the prototype bits.

Online maurice turner

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Re: Talking about the drumbrake 3C
« Reply #205 on: August 22, 2017, 13:14 »
Have a look at the shape of the poly tank its absolutely unique!!!
81 Jota*7604*

Offline ianmaro

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Re: Talking about the drumbrake 3C
« Reply #206 on: August 25, 2017, 16:48 »
It's aluminium Maurice. ;)

Offline MarnixSFC

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Re: Talking about the drumbrake 3C
« Reply #207 on: August 25, 2017, 16:57 »
Cor's proto tank is made of fibreglass, slightly different shape to the production ones.

Marnix
International Laverda 750 SFC Owners Registry

Offline SoyBoySigh

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Re: Talking about the drumbrake 3C
« Reply #208 on: April 18, 2018, 02:47 »
BUMP!

What a great thread - fantastic pictures! I love it.

I've just got to say I've got reservations about using a drum brake on the front of an 80HP 1000cc Superbike!

And just what SIZE were these brakes again? Weren't they only 200mm in any case? Or are we talking more like a 220mm like some of the older GUZZI front drums? Perhaps 230mm like the Benelli 650 2xSLS double-sided "Doppel-Simplex" front drums? I've seen pics of their innards and the lining seems quite a bit smaller than the outer diameter, and I'm very well used to the Japanese wire-spoke drums for comparison so I've at least got plenty of sense for the normal proportions -

What I'm getting at here, is just what are the dimensions of the liner itself - diameter and width, as well as the shoes for that matter - plenty of these old drums had quite a lot of "slop" on either side, shoes as much as 10% narrower than the drum liner itself - One might look at running length of the circumference or perhaps the proportion of the full 360-degrees which is covered by shoes rather than a gap around the pivot post & cam - Obviously some of 'em are more efficient than others.

I've got a few 200mm drums I'm tinkering with right now, I've figured out using Suzuki T500 3LS shhoes, filed down to width, in the Suzuki 4LS drum so as to take up the "slop", plus I've figured out reversing the cams from left vs right sides so as to ramp up the cam action with the greater lift of the corners which haven't been filed down round, plus the T500 arms & links weigh 50% less & the rod's a 5mm pull type rather than 6mm push-type so it's stronger despite being lighter - I've opened up the air scoops all the way leaving only enough material to retain the threaded holes for the cover screens (as if they'll ever be needed, and I'd much rather fit something that'll flap open on a hinge widening the scoop mouth even broader) AND I've cut/carved ventilation slots along the center-line between the spoke-flanges, aligned 'em with the existing side-to-side holes in the center wall so as to create a fan/vane to push/pull the air out as the wheel turns - which required the drum be flipped 'round to run in reverse (call it the Ferris Beuller odometer mod?) and that meant filing off the lugs which run the mechanical speedometer & I've gutted that to fit a magnetic speedo sensor which will be threaded down a hollow old cable sheath, allowing a bushing insert to reinforce the now hollow speedometer well, ALL IN ALL some useful mods most of which don't even modify the external appearance - But I'd very much like to try something much more radial, and so I'm on the hunt for some beefy thick 8" shoe liner pad & either mounting rivets or the same adhesive used on mass-manufactured OEM shoes - 'Cause it should be feasible to skim the 200mm drums out to the 203.2mm's (PLUS the additional range of maximum servicable wear) To not only lighten the drum liner, but to get that extra smidge of working diameter & mechanical leverage. I'm not sure whether it'd be better to re-line the existing shoes, or to modify the PIVOT area of some other shoes so as to make 'em work with the correct shoe-plate, but either which way, it would be a decent modification.

If and when I manage to use a really over-sized drum on a slower more lightweight application, a sub-125cc four-stroke, Honda CUB clone type of build, for which I've set aside a T500 Titan 200mm 2LS hub, I'd very much like to try and CROSS-DRILL a drum brake!

I realize it's not at all recommended for a composite construction "AL-FIN" type Iron/alloy hybrid drum hub, but on the AUTOMOTIVE type Hot-Rod rear drums, they used to cross-drill the one-piece Iron bolt-up type drums, something analogous to a Harley "JUICE DRUM" let's say or the Norton Commando rear drum, etc etc - well these should function no differently than the Automitive type. The period magazines spoke of this DIY mod as a significant upgrade which gave older drum hubs the same "BITE" as a rear disc-brake replacement!

Now, I'm sure it would weigh a whole ton, but there are older Brit-bike SIDE-HACK racers which used front drums from automobiles for a double-sided Hydraulic 8" sls brake, basically a "Doppel Simplex" type of deal, but with a smaller disc-brake type HUB in the middle with the requisite spoke lacing which might look odd paired to a 4LS style front brake. But here's the thing - there are OTHER types of Automotive rear drums which were both hydraulic and "AL-FIN" type composite, to the tune of 10" diameter Datsun/Nissan rear drums or even the Buick 12" type with the big fins on 'em! If only it were possible to drill their outer lip edge for the spoke holes, then only a central bearing-spindle need be bolted into the middle of 'em, and the spoke lacing would be simpler. It would probably require a 19" rim or even 20"-21" to lace up the 12" Buick drums in this fashion, but the 10" Datsun stuff seems to have potential - And their "wheel-cylinder" type hydraulic slave cylinders have a separate housing for each shoe which is to say they have a 2LS/4LS action rather than the conventional SLS action of most automotive type drums. It might wind up being ridiculously heavy, if for no other reason but the assembly bolts themselves. But it would be a hell of a cool brake in any case.

I realize it's not applicable to a non- SIDE-HACK Laverda, a 2-wheel "SOLO" that is to say. But it'd be very cool on a side-hack racer. Maybe even just bolt up a center-flange Akront "NERVI" rim sandwiched between the two drums, no spokes at all! Could be one awesome side-hack brake, and it'd all be period-correct too. Just a brain-fart is all....

As for the C3/Jota I'd feel too sketchy heck I dunno about the conventional 2LS drum on an SF 750 twin! At the very least, one of the 230mm 2LS drums disguised to look like the OEM type? Better yet a 250mm-260mm - The 270mm 4LS used on the Kawasaki H1R 500cc too-smoke triple?

It's about the way that TRAFFIC has changed, is all. I'm sure they were adequate for noodling around in traffic back in the DAY, but for modern roads I'm of a mind even the period-correct dual-disc set-up ought to be scaled up a few mm's/cm's worth of diameter!



-Sigh.

Offline helicopterjim

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Re: Talking about the drumbrake 3C
« Reply #209 on: April 18, 2018, 03:09 »
Still pretty cold there in Alberta, eh Silas!
74 SFC
72 SF
75 3C
79 (81) Formula Mirage 1200
Various Ducati's, Guzzi's, Puch's ... a BSA Sloper and maybe even an R90
I don't have a 1977 Honda XL 175

Chilliwack, British Columbia