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Darmah "Splitter" single throttle cable

Posted: Mon Mar 17, 2008 11:47 am
by Spub
Had the sh@$%&!t scared out of me this past weekend when the throttle cable snapped on my 1980 DarmahSSD. Every try to get over 4 lanes on a busy SoCal freeway with no power? Exciting business...As you know, this model has the single cable at the throttle, with the splitter running separate cables to the carbs. I have read articles discussing the short life of the single cable, which generally breaks right at or just short of the barrel end in the throttle, and have contemplated the twin pull tomaselli conversion. My problem is this would require me to move the brake lever/reservoir unit to the left on the right side clip on to make room for the new lever, which wil now be mashed up against the starter button/run switch, which must be retained from the old single pull throttle. Unfortunately, on my Darmah SSD, this fouls the reservoir/brake hose on the tach. I could angle the bars back more to try to pick up some clearance, however the bars would really have to be angled back quite a bit.

Another option would be to route the single pull cable better, which I have tried to do. I have looped the cable aroung the head tube and have it come back through just behind the head tube on the right side, where it routes to the front and rear carb. This has improved the forces required to active the throttle, howeve a snapped cable still concerns me.

I have seen what is described as twin pull Verlicchi throttles that have a run and starter button for sale on Ebay. Anyone try these on a 900 engine? Since it has the run and starter button, it solves the spacing issue.

Alternatively, if anyone has found a way to make the Tomaselli throttle work on a Darmah SSD, I would appreciate learning how you did it (without swapping bars).

Posted: Mon Mar 17, 2008 12:32 pm
by BevHevSteve
hey Stephen, the verlicchi throttle that is off a pantah with a starter button is great if you can find one. I use a starter button from a moto guzzi on a little bracket I cut, fastened to 1 of the screws on the brake master cylinder clamp. It works a treat and solves this issue.

Tammaselli 2C daytona throttle with starter button on my SSD. You can kinda see it below on the right...........

Image

Twin pull throttle for a SSD

Posted: Mon Mar 17, 2008 2:15 pm
by Craig in France
Hi Stephen,

Glad to hear you're ok, even if your pants may need some attention :)

Yeh, the Tomaselli 2c Daytona unit isn't an instant solution, altho' Steve seems to have come up with as good an answer as any.

Coincidentally, I've just left my SSD with Tony Brancato for, among other things, the fitting of a Verlicchi twin pull.

(Btw, he advises running a spare cable alongside the working one. Now, that wouldn't have helped you cross the 4 lanes, of course, but it might have helped getting home afterwards! Also, if you haven't already done this with your clutch cable, I would strongly recommend it!)

Anyways ...

1. If the eBay item you're looking at is this one - 200206006495 - be careful. Look carefully and you'll see it's only an empty casing - no switches.

2. Your current cable routing sounds right. Personally, I haven't heard of the single cable being especially prone to breaking, but ... The main reason for fitting a twin pull is to reduce the difference in length between the cables that go to each carb. Being different lengths, these stretch differently which can make balancing the carbs difficult.

3. If you want to go down the Verlicchi route, Pantah twin pulls can, as Steve implies, be hard to come by. If you have trouble locating one ("Mug a Pantah Owner Today"? No, that's not behaving nice ...), it may help to know that a few other bikes had variations of the Verlicchi throttle, including Morini 350/500s and some Cagivas (no surprise there), for example. The wiring may be slightly different, but that's not too much work to correct.

HTH

Craig

Posted: Mon Mar 17, 2008 4:52 pm
by Spub
Steve: I think I'm gonna look for a Pantah throttle, as it see it has a twin cable, with the run and starter button, just like the Verlicchi. My 900SS holds "tune" longer than the Darmah ever has, with its twin cable Tomaselli throttle, but the real reason I would switch is so keep my shorts clean, as Craig pointed out.....

Craig: You are also on the Laverda site, no? I have a late 180 JOTA (1982). As you know this uses the same throttle as the Darmah, but with a larger gauge single cable going to a bellcrank which operates 3 32MM dellortos, so while it has a heavier load, it has a spec'd up cable. I guess this is to be expected, Ducati has the dainty, more delicate part, and Laveda has over-engineered theirs so it would take a direct nuclear hit.....

Posted: Tue Mar 18, 2008 4:34 am
by garryc
I have just replaced my tomaselli twin cable throttle with a ?verlicchi twin cable that I bought on OZ ebay for all the reasons you stated. My darmah has clip ons and I needed double jointed thumbs to reach the starter button, brake lever located way left of where it should be etc,Have put the original bars back on much better suited to my advancing age. Bought it after auction ended. Cost $200 Aus. Looks like a cheap plastic copy, needed to fit the multi pin connector from the old switch as the new multi pin was different. Have a look at Steves shop, as I am pretty sure he has a replacement and when I checked it would have cost about $140 Aus to buy it from him + postage Isn't it wonderful how weak the US dollar is
garry

Verlicchi throttles

Posted: Tue Mar 18, 2008 4:02 pm
by Craig in France
Spub wrote: Craig: You are also on the Laverda site, no?
Hi Stephen,

Yeh, that's me - RGS Corsa, simply the best bike Laverda ever made; plus a Zane 750 Formula, which is also pretty damn good - well, at least until the crank goes bang ... so a bit like a Ducrappi, really :-D

Good luck in your search for a Verlicchi unit - just to be clear, that's what you find on Pantahs. As Garry says, they don't look too solid, but maybe sometimes we have to sacrifice a bit of 'Bella Figura' for functionality. And you may have to alter some of the wiring terminals.

Ciao

Craig

Posted: Tue Mar 25, 2008 1:40 pm
by Spub
OK, I scored a Pantah throttle off of E-bay...this one actually had the switch and starter internals unlike the one that sold last week, and it sold for less, if you can believe that...

I suppose the Pantah throttle cables will work, no? (I have the stock PHF carbs rather than the 40 PHMs). Also, re-reading Stephen Eke's book he states converting from a one cable/splitter throttle to a dual cable type will result in "real" gains in torque and horsepower....all this from adding one additional cable....(Mr. Eke, if you're reading this, I did read your book, and while I am having some fun at your expense, it has added to my bevel knowledge base)....I have an old beat up Darmah throttle unit that has the green 3 pin electrical connector which I'll snip off and attach to the Pantah throttle, just have to fiture out the wiring...

Posted: Tue Apr 15, 2008 1:15 pm
by Spub
Installed the Panta throttle two weeks ago, and balanced the carbs and rode the bike this past weekend. The Panta throttle I got is a twin cable throttle, but unlike the Tomaselli throttle, has a engine "run" and starter button built into the throttle. Unfortunately, the whole unit is plastic and a bit cheap looking, but hey, it works and solves my spacing issue.

I guess I owe an apology to Stephen Eke, because the Panta throttle seemed to really improve the throttle response and (to a lesser extent) power compared to the single cable/splitter Nippon Denso stock unit. I suspect this is due to the very accurate balancing that can be had with the twin cable set up vs. the single cable set up. Especially noticeable was the improved response at small throttle openings, something the Nippon Denso throttle was never good at, due to the increased friction inherent in the design (vs. the twin cable set up). Now, I'll take a break from this bike and try it again after a respectable cooling off period, to determine if the foregoing is a placebo effect or not, but for now, I'm very happy and surprised by the improvement. My Darmh now runs as well as my 900SS (well, a tad down on power comparatively, but you know what I meant).