Dual vs. Single Throttle Cables

[ridesolo]

I've got to get off my posterior and order new clutch and throttle cables for the 360/378 so I can get it finally buttoned up and done. I need cables shorter by 6-8 inches so I'm ordering cable kits that I can set to the right length.

I've never completely understood the need for the dual throttle cables especially since there's a return spring. The idea of a second cable has always seemed redundant to me. I've noted comments here in DTT that the second cable isn't needed, but thought I'd seek out a consensus before pulling the trigger on an order.

So, If I originally had dual cables would it be best if I replace both? Or will a single throttle cable be fine?

 

[Sderbyshire]

I think the close cable is a safety measure in case of spring failure, i’m thinking double springs and single cable for the 550.

 

[pidjones]

One advantage of dual cables is that your right arm doesn't get twice the size of your left overcoming a spring big enough to ensure safety if the pull cable breaks.

 

[ridesolo]

One advantage of dual cables is that your right arm doesn't get twice the size of your left overcoming a spring big enough to ensure safety if the pull cable breaks.

That sounds good, I guess, but in all the miles I've done on all the bikes I've ridden I've never broken a throttle cable. I spoze it CAN happen...

 

[doc_rot]

depending on the carb design and engine vacuum the slide can stick open at WOT with single cable, this is why all flatslide carbs are push/pull. dual cable can improve throttle response down low as well

 

[irk miller]

That's really what it comes down to with a CV. Not only can it stick, but the spring working against vacuum slows the down throttle. Depends where in the throttle range and how stiff the spring for how much the effect. If you want to go with a lighter spring to soften your throttle, that's pretty much out the window running a single cable.

Mikuni TM flatslide carbs are just single cable, but Keihin FCR flatslides are push/pull.

 

[Maritime]

CV Carb = dual cable for me for the reasons mentioned above and also I've had a cable break and you can swap your push to a pull to get you out of that situation.