Quick action throttle

[Davo]

I would expect you would really need the accelerator pumps to work well or it will bog with a fist full.

Exactly what my Le Mans does, especially when cold.

 

[Legs]

OK Carlo, have to ask, what do all those buttons do and what is that little lever?. Terry from the Stone(s) age.

 

[Vince]

Photon Torpedos.

 

[Laverda SF]

Perhaps a 625hp 7000rpm GM MK IV SR 460ci with a Holley DP or Annular Carb on Pump Gas on 4 wheels - Fuck the gas mileage ;o)

 

[piranha-bro2]

I can't imagine how heavy a triple throttle would be if it were 1/4 turn!! Lav twins are bad enough std. Racing the 1200 in the Castrol 4-Hour with s std throttle was a pain the arse (well, wrist actually  ), two handfuls out of every friggin corner!

I managed to retain my original switchblock with a QA throttle by using the plastic barrel from a KX Kwaka dirt bike and grinding the opening part of the round (ie the part that opens off idle), drilling the nipple hole closer to the inside radius, then creating a 'rising rate' QA throttle (shaping the cable barrrel like a cam lobe) where the first part of the twist is gentle and retains smooth and light action around town and cruising but when you want a fistful the ratio ramps up and it opens a lot quicker. With cut-down springs it worked a treat and I didn't lose the look of the original ND switchblock.

I'll lose that now that I'm going to FCRs, but might look at something like Robber's CBR250 switchblock and barrel.

 

[Davo]

I used a "tamer" from these guys on the Yamaharley as it needed a bit slower action from idle to go. Very well made gear but I don't know what the quick action throttle is like. However it looks like it would be a straight fit into the existing switch block and just replacing the throttle tube.

http://www.g2ergo.com/product-category/street/

 

[cbertozz]

OK Carlo, have to ask, what do all those buttons do and what is that little lever?. Terry from the Stone(s) age.

The little lever is a thumb brake. I've never used the rear brake on track but it helps keep the front down whilst allowing you to stay on the gas (I've turned off wheelie control to get better drive out of the corner), and it helps tighten your line without unsettling the bike, also settles the bike before braking had, and finally is just some extra stopping power.

The buttons are just for selecting and changing the various parts of the traction control, wheelie control and launch control - navigating the dash.

Allens Performance Products for the multiplier, a black coloured one, 1:1.33 ratio, with part number 1771.91 or there is a higher ratio of 1:1.77 which is grey with part number 1933.91.
I intend to give one a try.

Im toying with this or Davo's suggestion further down the page.

From my experience the faster the Throttle the thicker and more tapered the needle with Stock jets (Not getting into Exhaust Systems).

Perhaps a stock needle; but, bigger main Jets is necessary with Bigger Valves and new valve springs with a free flowing exhaust - What's your take?

My mouse is dying - need a new one ;o)

It's been a pretty seamless transition, doesn't seem to bog but maybe on the track it could benefit from different setup but for road it's fine so far.

I can't imagine how heavy a triple throttle would be if it were 1/4 turn!! Lav twins are bad enough std. Racing the 1200 in the Castrol 4-Hour with s std throttle was a pain the arse (well, wrist actually  ), two handfuls out of every friggin corner!

I managed to retain my original switchblock with a QA throttle by using the plastic barrel from a KX Kwaka dirt bike and grinding the opening part of the round (ie the part that opens off idle), drilling the nipple hole closer to the inside radius, then creating a 'rising rate' QA throttle (shaping the cable barrrel like a cam lobe) where the first part of the twist is gentle and retains smooth and light action around town and cruising but when you want a fistful the ratio ramps up and it opens a lot quicker. With cut-down springs it worked a treat and I didn't lose the look of the original ND switchblock.

I'll lose that now that I'm going to FCRs, but might look at something like Robber's CBR250 switchblock and barrel.

It's really not that different in terms of heaviness. If anything the fact that you have to turn less means your wrist is at a more comfortable angle with open road riding.

I would like to have the original switchblock but enjoying the change for now.

I used a "tamer" from these guys on the Yamaharley as it needed a bit slower action from idle to go. Very well made gear but I don't know what the quick action throttle is like. However it looks like it would be a straight fit into the existing switch block and just replacing the throttle tube.

http://www.g2ergo.com/product-category/street/

Looks like a good option. What model did you select? (they don't list Laverda unsurprisingly)

 

[Legs]

Thanks Carlo, thought it might be a thumb brake.

 

[psg]

Thanks Carlo, thought it might be a thumb brake.

Developed by Mick Doohan/HRC MotoGp I recall when he badly smashed up his right leg, but still needed to use the rear brake for the same reason cbertozz does, but his leg was too weak.

 

[Davo]

I would like to have the original switchblock but enjoying the change for now.

Looks like a good option. What model did you select? (they don't list Laverda unsurprisingly)

As stated I bought a "Throttle Tamer" for the Yamaharley I used to own as the transition from idle to go was very abrupt and their tamer slowed down that action. You would have to sort out which quick action tube suits the Laverda switchgear but I would assume starting with the Suzuki stuff would be a start. Once you have sorted out what suits you could let the rest of us know 

I did note while reading through the specs that different inserts can be fitted to the "cammed" section to allow for different throttle action rates. Sound interesting.

 

[Dellortoman]

I reckon a neat solution would be a programmable fly-by-wire setup.

I've not tried it, but I suspect it's do-able with Ignitech ignition which has a servo output that can be mapped to a TPS input. Basically what you'd need is a twistgrip TPS to provide the input signal and a suitable servo motor to drive the throttle shaft on the carbs. Any heavy throttle issues would be a thing of the past too.

 

[Grant]

Make one for the clutch too, no more heavy pull clutch.
I think Honda made a similar set up for the front brake, and had fitted a rubber stop to give 'feel' at the brake lever.

 

[CLEMTOG]

"Developed by Mick Doohan/HRC MotoGp I recall when he badly smashed up his right leg, but still needed to use the rear brake for the same reason cbertozz does, but his leg was too weak."

Nope, It was me that invented that one,
I beat him by about three years it was fitted and working on my Monty in 1979, using a cable type lever under the clutch lever (suitably cut down) and a cable running from it, down to the master cylinder to activate the brake hydraulic bits, it stayed there for three years and was then removed to satisfy a fussy scrutineer, and first race after that was my last as I crashed, wrecked it, and sold the bike to a Mr P J Todd and rode away on TOG which at that time was called "Ivy" due to reg number of EYX IV. funny that I was using the brake to stop the rear end from stepping out, when hard charging up the gears on exiting the corners, and couldnt use the pedal at all due to an old injury, that one last race was done without a rear brake.
CLEM
ps Oh, did I mention that another crashing Monty and an a 500 Suzoook with a spanny dragging in the road where all about at the same time?

 

[Alexb83]

Well, I had a bit of a faff with this recently.
7 years or so I have been operating my triple with mikuni carbs, stock switch gear, a push/pull throttle and a cut down grip/throttle tube to get it all to fit onto the bars.
My switchgear was also left in a dubious state by the previous owner and has needed repainting but that's another story.

This last week, the grips gave up the ghost and so rather than butcher another one, I decided to set the whole thing right by trying to adapt the ND switch gear to receive a two cable suzuki throttle tube replica, 3d-printed by that fella Steve B.

Ordered a promising bottom half for my right hand switchgear, only to find that while it is cast to accommodate the two-cable tube and wheel, it isn't drilled or tapped to receive a second cable and also has no hole for the starter button. Bugger.

Looking on a popular auction site at another version of the switch gear bottom half, I see it is drilled for the cables but again, not the starter button. So that too will need work, and it's not clear if it will fit the throttle cable connections even if it has enough metal to be remachined.

So in the end, I put that little project on the back burner until I can get a man to do some machining for me, and fitted a modern domino RHS switch gear and one of their xm2 throttles. Absolutely no rivets to count.

 

[Jo]

I used a NOS Suzuki GT550/750 throttle/switch gear when converted mine to Mikunis. Switch gear is identical to Laverda. I'll search and will post it here.

 

[Jo]

Hi Alex,

Here’s my story regarding this subject:

Step by step


And there’s obviously a dealer offering Suzuki GT550/750 switchgear/throttle grips in the UK (I ordered mine from the Netherlands in 2018) – the link shows the german e-bay page however – but that’s what I ordered & used in 2018:


Suzuki GT550/750 switchgear/throttle grip


Hope this will help you!

 

[Alexb83]

Hi Alex,

Here’s my story regarding this subject:

Step by step


And there’s obviously a dealer offering Suzuki GT550/750 switchgear/throttle grips in the UK (I ordered mine from the Netherlands in 2018) – the link shows the german e-bay page however – but that’s what I ordered & used in 2018:


Suzuki GT550/750 switchgear/throttle grip


Hope this will help you!

Thanks Jo, that thread is a great resource.

For now, I will use the modern setup - I've stripped, basically painted and rebuilt my old right hand switchgear, and now have a suitable 2-cable throttle tube ready to re-engineer the below (third variant!) casing to accept the start button.
You'll see that the casting does have the slot needed to fit the small PCB for the button, only the hole on the front of the casing for the button is missing in this case.



Once I sort that, it's just a matter of finding cable ends that fit properly (my current 'return' cable at least does not, even if the 'pull' cable does), then I will have a 'period' set of spares that I can revert to if I don't like the Domino setup.

I don't want to keep throwing good money after bad, and it is cheaper for me to buy up these scrap casings and see if I can persuade my neighbour to adapt them in his workshop for the price of a few beers.

 

[piranha-bro2]

My conversion for Keihin FCRs was dead simple - buy a two-cable throttle assembly from a Suzi, as per Jo. Not quite sure why you've created several rods for your back! But sounds like you've got there in the end.

I actually ended up running a single pull cable anyway - have never had any reason to fear my decision. No doubt the naysayers will be along soon with tales of impending doom. BTW, haven't seen a triple on Dells running a 'push' side to their throttle assembly - not quite sure why the placement of the return spring makes any diff (in the slides or on the shaft).

 

[Alexb83]

My conversion for Keihin FCRs was dead simple - buy a two-cable throttle assembly from a Suzi, as per Jo. Not quite sure why you've created several rods for your back! But sounds like you've got there in the end.

I actually ended up running a single pull cable anyway - have never had any reason to fear my decision. No doubt the naysayers will be along soon with tales of impending doom. BTW, haven't seen a triple on Dells running a 'push' side to their throttle assembly - not quite sure why the placement of the return spring makes any diff (in the slides or on the shaft).

Part of it is just suitability and the other part is cost - even the link Jo posted above for a suzuki switchgear is for one with only a kill switch, without a starter button, if you look.

The objective is to run a 2-cable throttle, kill switch and starter that looks close to original, and if not possible, move to a modern alternative (which is where I am currently).

 

[Jo]

<snip> - even the link Jo posted above for a suzuki switchgear is for one with only a kill switch, without a starter button, if you look. <snip>

No, the pic of the used one also showed a starter button. Anyway, Suzuki built the same switch gear with and without a start button, with one and two throttle-cable connections; it was a modular concept. And, most importantly, they're identical to those on contemporary Laverdas ...