Stupid throttle return cable question

I have a couple of bikes with return cables. One broke years ago, and
I never replaced it. It doesn't seem to make any difference, as the
throttle spring on the carb returns the throttle to closed.

What do I not understand correctly?

 

One motive for dual cables is balancing out the effect of cable
flex: Tension in a single cable changes a little when the cable
is bent, having two cables working against each other cancels most
of that tension change out.

I'm not sure that's the _motive_ for dual cables, but it's an advantage.

bob

 

Motive, I think, originally, was US product liability laws.

 

iirc, Harley used them for technical reasons before the lawyers decided they
were a Good Thing.

 

I remember some deranged Italian marketed a push/pull conversion kit for
the old Guzzi Le Mans marks One to Three, whose 38mm slide Dell' Ortos
were ferociously heavy.[1]

It worked, but it made the throttle *heavier*.

[1] Later marks had 40mm carbs and were even worse.....

 

Harleys once had a single cable open and close the throttle before the
advent of return springs. But they didn't start using a second cable
until 1981.