I am having trouble setting up my hercules 3 speed gear shifter. It seems that the cable is too long. On top of that the cable that is supposed to affix to the trigger keeps coming out from its SA trigger. I'd like to change the trigger to another style that does not use the same type of cable attachments but I'm having trouble finding sites that show how they sit on the handlebars. I'v seen only one site ( SA) and some look as if they sit on the end of the handlebar (?) Is there a way to shorten the cables for a correct fit? As of this point no matter what speed I select ( even with cable sitting in ) there is no movement to the hub chain at all. Can I shorten the cable? thanks in advance.

Is this a new SA three speed or an old one? I was assuming new based on your use of the SA site, but you said Hercules. I'm confused. For all things old-three-speed related, see Sheldon's site:

https://sheldonbrown.com/english-3.html

Harris Cyclery (for whom Sheldon works) sells lots of 3-speed bits.

Once I know if it's old, I can help. If it's new, I can't.

Sounds to me like your cable stop clamp is set too far aft, allowing the cable housing to be loose. Get that cable stop slid fwd (if there's room, if not, you need either a re-routing or a different cable) and what you describe will go away.

BTW, that shifter has been pretty good for 90 years or so.
alf

Old and new can use the same shifters. I'm using a new hub with a '70s shifter because I don't like the plastic twist shifter that came with the new hub. I've got the old fulcrum clip and pulley, too. The only difference is that the new shifters take a different cable end.

For the OP:

You can shorten the cable if you need to by using a bolt-on anchorage.

https://sheldonbrown.com/harris/sturm...her-parts.html

The one i have currently is an older one from about 1974ish. It ha s cracked plastic covering but moreover I am frustrated at having the cable constantly pop out and it doesn't have any tension at all.
My bike is a hercules , the shifter is A SA.

If the end of the housing is popping out of the shifter, it's too loose. The clamp has probably slipped as old alfie said. All you need is a screwdriver to fix it. You can still buy the trigger shifters new. The one you have with the clear plastic is probably the same one that I bought new on eBay. I don't like the looks of the current production trigger shifters, but they work the same as they always have.

I have ordered an anchorage and should get it any day now to see if that extra tension will stop the cable from popping out of the housing. Personally with tension aside I wonder if my shifter is working correctly at all but that will be determined once I get better tension on my unit. I don't have experience to compare it to. I've also noticed the cable housing has separated from the ferril but I assume that is not an important issue. To further explain the situation none of the housing unit of the trugger itself is loose...just the end of the cable keeps popping out. Sadly the design does not have anything that allows the cable end to "clip" into place or retain it there from what I can tell.

if you flip the trigger into the "3" or "high" position, there is a little slot that the cable end seats in. if it does not fit, someone used the wrong cable. if it is seated in this spot and pops out, something is binding in the housing or possibly the shifter body.