Vibration - Chassis Cause Clutch Cable Failure

[mikeyb]

So, I spent several minutes looking through the very interesting thread about clutch cable failures here:
viewtopic.php?t=21703
and found that nobody had mentioned any physical damage to the outer cable, causing the inner cable to fray. My cable broke today (the inner clutch lever broke last month) so this has been the summer of clutch problems. I got 1900 miles on the inner lever before it failed and 2200 on the cable before it snapped.
HERE is where it gets interesting. I had a spare cable just for this occasion BUT when replacing the inner cable, I found it difficult to get the cable inserted more than 5 inches before it was blocked. Upon closer inspection of the outer cable, there were two places where the outer cable sheath was worn through because it was rubbing (possibly from vibration) where it curves down through the headset at the top after the handlebar tube AND near the back underside where the outer cable exits the metal unibody chassis. Both locations wear agains the chassis where there is a metal edge the sheath lays against. My cable broke near the top where the sheath was warn through.
I can't fit my inner cable through the top because the outer cable is damaged. I will have to replace both the outer and inner cables BUT I am thinking of placing some sort of protective padding where the outer cable rubs agains the unibody chassis.

Maybe I am making too many assumptions but based on the routing and the metal rubbing against the cable, I think this may be causing premature failure.
Share your thoughts.......

Mike

[fisher1]

Nice going in tracking that down. Are you thinking of actual padding, or of a meal shim/sleeve of sorts at the pressure point ?

[mikeyb]

Yes, I do plan on putting some sort of sick plastic guard at the pressure point and taping that in place on the cable. What's really interesting is the exit point from the chassis on the underside back end of the bike. The Chassis Exit point is in the shape of a "V" And the edges are bent and jagged.

I also am thinking about putting a different cable in. I'm wondering if there might be a stronger cable, possibly solid wire, that would not be so prone to break. I'm not sure if there is such a thing but it seems to make sense to me.

Also, I am curious if anyone else may have a similar chassis with jagged edges or if it is unique to my bike?

[Stilts]

Yes, I do plan on putting some sort of sick plastic guard at the pressure point and taping that in place on the cable. What's really interesting is the exit point from the chassis on the underside back end of the bike. The Chassis Exit point is in the shape of a "V" And the edges are bent and jagged.

I also am thinking about putting a different cable in. I'm wondering if there might be a stronger cable, possibly solid wire, that would not be so prone to break. I'm not sure if there is such a thing but it seems to make sense to me.

Also, I am curious if anyone else may have a similar chassis with jagged edges or if it is unique to my bike?

While not a Stella, my friend's ~'70 Rally 180 has a similar problem. He goes through clutch cables like there's no tomorrow.

[BuddyRaton]

Some people will route the outer to the opposite side of the fork tube inside the headset. It gives a bigger arc for the inner and relieves some stress but it starts making things a bit crowded in there.

You may also want to consider changing the outers to high quality teflon lined. Scooterwest is probably the best source for them. They are cut to length for each model. Also don't forget to keep those cables lubed!

[mikeyb]

Is there such a thing as a solid inner cable for the Stella?

[BuddyRaton]

Is there such a thing as a solid inner cable for the Stella?

Not that I have ever heard of. It would be tough to pull one through, tough to pull the clutch, and not as strong as braided cable. Cables iners and outers, are one of those things that are worth a couple more dollars to get higher quality.

I honestly don't know but I would not assume that a Stella has high quality cables.

[mikeyb]

Thanks for the replies David. I contacted Scooterwest and asked them if they had any higher quality cables than the stock cable for the stella. The parts guy gave me the impression that the cable quality wasn't any different as far as strength goes but the difference was the cable was teflon coated??? I opted with the standard cable and used white lithium grease to lubricate.
I ended up replacing the entire outer and inner cable and wrapped some aluminum heating and cooling foil tape around the two areas where the cable touches the chassis and rubs.
The bottom exit point area and bent downward to round and soften the touch and there wasn't really anything I could do with the area in the head other than wrap and protect the cable from the hard point there.

For those who have not yet experienced the infamous cable breaking there are a couple of warning signs before it happens:

1. There will be a clicking feeling in the clutch handle when you pull the clutch handle in and some of the cable braids break. Some may explain the feeling something like maybe when the cable felt like it was stretching a bit. After that point I got about another 15 or so gear changes before it broke.

2. The clutch lever felt harder to pull in and seemed to not be as smooth when I pulled in the clutch. This went on during the time I believe the cable was frayed and was getting ready to break.

Others may have had different experiences but that is what I felt. The best thing that can happen is you learn how to change out this cable. If you feel you don't have the skill, ask your dealer to let you watch when they change it out so you will know how to do this. It would really be a simple repair on the road...... as this will break while you are riding (most likely).

One last thing. The 4th hand tool would have made life a lot easier. I used needle nose vice grips and it worked but this tool http://www.scooterworks.com/tool--fourt ... -11936.php would have made life a lot easier.

So, time to review my onboard tool kit and include one of those along with a spare cable for the clutch.

Mike

[BuddyRaton]

Max at Scooterwest knows his stuff. Personally I use the teflon lined...well worth the extra couple ducats if changing outers.


Not David

[jimmbomb]

Thanks for the replies David. I contacted Scooterwest and asked them if they had any higher quality cables than the stock cable for the stella. The parts guy gave me the impression that the cable quality wasn't any different as far as strength goes but the difference was the cable was teflon coated??? I opted with the standard cable and used white lithium grease to lubricate.
I ended up replacing the entire outer and inner cable and wrapped some aluminum heating and cooling foil tape around the two areas where the cable touches the chassis and rubs.
The bottom exit point area and bent downward to round and soften the touch and there wasn't really anything I could do with the area in the head other than wrap and protect the cable from the hard point there.

For those who have not yet experienced the infamous cable breaking there are a couple of warning signs before it happens:

1. There will be a clicking feeling in the clutch handle when you pull the clutch handle in and some of the cable braids break. Some may explain the feeling something like maybe when the cable felt like it was stretching a bit. After that point I got about another 15 or so gear changes before it broke.

2. The clutch lever felt harder to pull in and seemed to not be as smooth when I pulled in the clutch. This went on during the time I believe the cable was frayed and was getting ready to break.

Others may have had different experiences but that is what I felt. The best thing that can happen is you learn how to change out this cable. If you feel you don't have the skill, ask your dealer to let you watch when they change it out so you will know how to do this. It would really be a simple repair on the road...... as this will break while you are riding (most likely).

One last thing. The 4th hand tool would have made life a lot easier. I used needle nose vice grips and it worked but this tool http://www.scooterworks.com/tool--fourt ... -11936.php would have made life a lot easier.

So, time to review my onboard tool kit and include one of those along with a spare cable for the clutch.

Mike

MIKE.... thanks for the warning signs write up...
Can you say where your cable frayed and broke at?
Mine have always broken at the clamp...
Thanks

[jimmbomb]

When mine breaks at the clamp, my symptoms start as I feel the hand lever doesnt return all the way out sometimes. Usually a flick of the lever will make it spring back fully.
Then it gets worse and the friction point gets closer and closer to the grip.
(I like my clutch grab point way out near the end so I dont have to pull it in all the way to shift)
Im trying an experiment now...
When this cable breaks at the clamp...I hope to not have to run a new inner...
Used a piece of tubing to extend the clamp point. Then I hope to have another inch and a halt left to put in a new clamp on the same cable..
wish me luck..
[

And

[Robbie]

jimmbomb,

If your cable keeps failing at the clamp by the release lever it usually means a part is missing in the clamp.
There is supposed to be a tiny barrel over the section of the bolt that pinches the cable.
Without the barrel, the bolt cuts the cable while being tightened and, of course, the remaining strands will sign off sooner than ever.

Rob

[jimmbomb]

Right, Robbie....I know about that shoe...but ALWAYS seem to forget about it during set up..
Then I remember after..and its too late..damage to done...order another inner..stuff it in the glove box

[BuddyRaton]

Right, Robbie....I know about that shoe...but ALWAYS seem to forget about it during set up..
Then I remember after..and its too late..damage to done...order another inner..stuff it in the glove box

If you don't put the disc inside the pinch bolt you will keep breaking cables. The tube looks like it might give you a little more roon for getting the 7 and 8 mm wrenches in there.

You are also missing your slack adjustor.

[jimmbomb]

Right, Robbie....I know about that shoe...but ALWAYS seem to forget about it during set up..
Then I remember after..and its too late..damage to done...order another inner..stuff it in the glove box

If you don't put the disc inside the pinch bolt you will keep breaking cables. The tube looks like it might give you a little more room for getting the 7 and 8 mm wrenches in there
.

You are also missing your slack adjustor.

Slack adjuster?? Ive only seen one adjuster in that area and have always called it a cable adjuster.. But slack adjuster is a new one on me..
If it's what Im thinking.. it is there.. screwed into the case...hard to see in the bottom picture since the brake cable is blocking most of the cable adjuster from view...
or..
is there another adjuster (slack) that goes on south of the clutch arm??
thanks..

[Robbie]

I believe I see the adjuster hiding behind the brake cable......camera angle causing confusion.

Rob

[BuddyRaton]

I believe I see the adjuster hiding behind the brake cable......camera angle causing confusion.

Rob

Good catch...my error

[mikeyb]

does anyone have an exploded view of the assembly (from the manual). I don't see a spacer like the brass looking one in the picture. I don't remember an insert inside the pincher either???

My cable broke up in the head because of a rub-through hard point of the chassis. Rubbed through the outer cable and the inner cable. Mine is a 4T by the way in case that makes any difference.

Mike

[Robbie]

does anyone have an exploded view of the assembly (from the manual). I don't see a spacer like the brass looking one in the picture. I don't remember an insert inside the pincher either???

My cable broke up in the head because of a rub-through hard point of the chassis. Rubbed through the outer cable and the inner cable. Mine is a 4T by the way in case that makes any difference.

Mike

The spacer in the photo is jimmbombs invention.

I was under the impression (meaning other posters help needed) the protector only came with the clamp assembly.
I do know you can lose it in the blink of an eye.

Rob

[mikeyb]

Not to argue with anyone but I am still trying to understand what a "disc inside the pinch bolt" is? BuddyRaton said:

If you don't put the disc inside the pinch bolt you will keep breaking cables.

I have the only pic I can find from a stella manual that shows the exploded view of the clutch cable assembly and specifically the end that receives the solderless nipple that crimps down the cable holding the tension against the clutch lever arm where the cable attaches near the motor/clutch. See the pics below. I circled the part and the part description with a red bubble for clarity.

So, I don't want to keep breaking cables and I am concerned that maybe I am missing a part. Right now, the screw that is part of the solderless nipple is screwed down hard keeping the cable from slipping. Will this damage the cable and cause it to break?

I also included a 3rd image of a photo taken from vespamaintenance http://www.vespamaintenance.com/body/cl ... lutch1.jpg that shows the nipple, but no disc with the pinch bolt???? Does someone have a picture of the disc?

Thanks,
Mike

[BuddyRaton]

Ok here you go.

There is a a small metal disc below the 7mm bolt. the cable goes through the hole with the disc above it. Then the bolt is tightened down.

[Robbie]

If the adjuster bolt has been screwed down against the cable without the disc, the cable is already damaged.......strands have been cut.

Rob

[jimmbomb]

Right. Ive screwed mine down NOT knowing where the disc is..
So I have already damaged my cable...
Or Maybe not.... 50/50 chance..
So I keep a spare inner in my glove box for the inevitable. ..

** Note**....
In Buddyraton's picture of the clamps....the metal disc is not pictured.