Topic: throttle 'push'cable necessary?

[000jeremy]

I'm in the process of putting new drag bars on my 77 cb 550f and I'm currently reconnecting the throttle cables to the assembly.  I'm having an impossible time getting both of the cables on.  Its almost like the cables are too short even with all of the slack adjusted in?  Anyway my 'push' cable is literally hanging on by a thread so I'm thinking of just disconnecting it so I can get it running again, just for a couple days until the new cables come in.  Is there anything bad about running with no push cable?  I cant think of anything...

[Steve F]

I've been running without one for 4 years now.  Just have to keep the cable lubed, and make sure the carb spring is strong enough to pull the carbs shut.  So far, the stock spring is fine.

[mystic_1]

The 'push' cable (actually a second pull cable) is a redundant safety feature ensuring you can close the throttle if the main cable breaks.  You don't, strictly speaking, HAVE to have one.


That said, if you're unable to get the throttle cables hooked up than there's a problem somewhere.  Check your routing, that can cause this issue.  Some workshop manuals have line drawings showing the cable routing.

mystic_1

[Inigo Montoya]

Either will work but the extra cable is like insurance. It is there in case of cable breakage or spring breakage. If your pull cable breaks, you can move the push cable to its spot and make it home. It is also insurance if the spring were to break or some other reason for the carbs not closing right.

[MCRider]

The 'push' cable (actually a second pull cable) is a redundant safety feature ensuring you can close the throttle if the main cable breaks.  You don't, strictly speaking, HAVE to have one.


That said, if you're unable to get the throttle cables hooked up than there's a problem somewhere.  Check your routing, that can cause this issue.  Some workshop manuals have line drawings showing the cable routing.

mystic_1

yes agreed with that. You should be able to hook up the A cable only and everything should work fine. Then hook up the B cable for safety. However, removing the B cable should not "fix" a problem. The A cable should work properly with or without the B cable.

just changing the bars should not keep you from reconnecting the cables properly. You'll have a longer loop of unecesary cable, just be sure its free.

Do not short cut this, if there was nothing wrong before the bar change, there should be nothing wrong after, just extra cable. If its not working smoothly, there is a problem.

Could be if the inside of the A cable is worn (where you can't see it) and the big loop you are now putting in it is now exascerbating the wear, you may need a new cable. If so, no shortcut, even lube won't fix an internally worn cable.  Such wear may not have been so noticeable when the cable was straighter.

[Duke McDukiedook]

I would and do keep both.
Drag bars should give you more cable length to route over stock, try rerouting like Mystic said.

[Qingdao]

Can you cut the return spring so that its not so hard to twist the throttle?

I could look, but I am lazy and its on topic!

[MCRider]

Can you cut the return spring so that its not so hard to twist the throttle?

I could look, but I am lazy and its on topic!

If the A side of the throttle is smooth and functioning properly, you shouldn't need to consider cutting the spring. Do forearm exercizes and install a throttle drag and twist assist.

That spring was designed to be acceptable to the broad public and sufficient to close the throttle. It needs to remain intact.

[1974CB750rider]

I would try to keep both, reason being I had a bad experience last year. My bike only had the pull cable when I got it. I rode it like that until that cable broke and then I put 2 cables back on it and I'm also running drag bars. This is just my opinion but I believe that running only the pull cable puts more stress on it, their for causing it to fail sooner than it normaly would. When mine broke I had to set my idle up to get me home, it was an interesting ride. LOL

[MCRider]

I would try to keep both, reason being I had a bad experience last year. My bike only had the pull cable when I got it. I rode it like that until that cable broke and then I put 2 cables back on it and I'm also running drag bars. This is just my opinion but I believe that running only the pull cable puts more stress on it, their for causing it to fail sooner than it normaly would. When mine broke I had to set my idle up to get me home, it was an interesting ride. LOL

I would agree there can never be a bad reason to run both.

However, for clarity, I would take issue with your reason, that running an A cable alone stresses it more.

Properly set up and adjusted, the A cable performs in isolation from the B cable. The B cable is only along for the ride until it may be needed in an emergency.

The A cable needs to be monitored for wear and lubed regularly. Eventually, the inner cable wears a groove in the outer cable housing (not the rubber, the coiled wire) at any point where there is a bend. That groove will increase friction and virtually no lube will improve the feel once that groove is established.  It is not visible, nor can it be felt when the cable is removed and held straight. The increased friction will cause stress at the ferrule and break the inner cable where it meets the ferrule, usually at the twist grip.

IMO  YMMV

[TwoTired]

Can you cut the return spring so that its not so hard to twist the throttle?

No silly, cutting/shortening springs makes them stiffer.

Do you get more spring from the middle of the diving board or the end?  The diving board is just a flat spring rather than wound.

I recommend more spinach!

Popeye: I'm your one and only exspring. See, we got the same bulgy arms.
Poopdeck Pappy: No resemblance.
Popeye: We-we got the same squinky eye.
Poopdeck Pappy: What squinky eye?
Popeye: That's going to be hard for you to see.

[MCRider]

"NO, SILLY, CUTTING SPRINGS MAKE THEM STIFFER
No silly, cutting/shortening springs makes them stiffer."

oh man that's right!

So has Qingdao been playing with us? 

if a plane tries to take off from a conveyor belt...

[Qingdao]

No silly, cutting/shortening springs makes them stiffer.

Do you get more spring from the middle of the diving board or the end?  The diving board is just a flat spring rather than wound.

I recommend more spinach!

Popeye: I'm your one and only exspring. See, we got the same bulgy arms.
Poopdeck Pappy: No resemblance.
Popeye: We-we got the same squinky eye.
Poopdeck Pappy: What squinky eye?
Popeye: That's going to be hard for you to see.

+1 hehe... sometimes I don't use my head.

Mine probably NEEDS a shot of lube.  Guy I bought mine from didn't like regular maintance. lol

[Raul CB750K1]

I would try to keep both, reason being I had a bad experience last year. My bike only had the pull cable when I got it. I rode it like that until that cable broke and then I put 2 cables back on it and I'm also running drag bars. This is just my opinion but I believe that running only the pull cable puts more stress on it, their for causing it to fail sooner than it normaly would. When mine broke I had to set my idle up to get me home, it was an interesting ride. LOL

The throttle cable of my Sanglas bike snapped and left me stranded just 15 miles from home. I have road assistance but I gave it a try before calling the cavalry.

An electrical wire and the pliers -both I carried on the bike-, some turns on the grip and I made it home.

[andy750]

I tired the one cable thing...didnt like it and promptly put the other cable back on...go for a ride with one cable and see if your revs hang up in the air..without the second cable you cant do much about it...yes I know if my carbs were perfectly clean this would not happen but they are not...however the second cable helps in masking the issue 

cheers
Andy

[Qingdao]

The throttle cable of my Sanglas bike snapped and left me stranded just 15 miles from home. I have road assistance but I gave it a try before calling the cavalry.

An electrical wire and the pliers -both I carried on the bike-, some turns on the grip and I made it home.

I LOVE IT.