MOTOBRICK.COM

TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: BobR on May 05, 2012, 10:50:23 PM

Title: Snapped Clutch Cable
Post by: BobR on May 05, 2012, 10:50:23 PM
Clutch cable snapped while on a ride today. (91 K100RS)  In 3rd gear at the time.  Broke off at the clutch lever terminal end.  I put a new cable on less than 2 years ago (and less than 8k miles ago), so I am wondering why it failed so soon.  I have bar risers on the bike.  I bought the replacement cable from Beemer Boneyard and they advertise it as "German made", however not OEM.  It's cheaper than a OEM cable (~ $25 vs. $38).

So, couple of questions:

1.  Does having bar risers necessitate a longer cable than stock?
2.  Do these cables need to be lubricated (I never lubricated it).
3.  Are aftermarket cables to be avoided?

Title: Re: Snapped Clutch Cable
Post by: mystic red on May 05, 2012, 10:55:43 PM
My take:

1. OEM

2. Don't lube the cable.

3. Do grease the nipples

4. Don't think risers have a thing to do with it.
Title: Re: Snapped Clutch Cable
Post by: Chaos on May 05, 2012, 10:59:56 PM
I've had a BBY clutch cable for the last decade with no issues.  I have risers, but that should not be an issue if the cable is routed correctly.  Snapping at the hand lever end, at the nub, is usually a sign of the retaining barrel not being lubricated and not rotating when you pull the lever, bending the cable and causing it to fail prematurely. (never lube the cable itself)  I think I'm going to lube my barrel right now while I thinking about it.  Thanks!
Title: Re: Snapped Clutch Cable
Post by: johnny on May 05, 2012, 11:01:55 PM
i carry a peice of aircraft cable and brass cable ends in my bung... when my clutch cable broke i simply slid the aircraft cable down the existing jacket... slid the cable ends in the clutch levers and tightened the cable ends down on the cable... i rode like that for about 20,000 miles before finally swapping out cables...

i can scrape up photos if you wanna take a look... all parts can be had at the hardware store for about 5 bucks total...

j o
Title: Re: Snapped Clutch Cable
Post by: BobR on May 05, 2012, 11:07:16 PM
I've had a BBY clutch cable for the last decade with no issues.  I have risers, but that should not be an issue if the cable is routed correctly.  Snapping at the hand lever end, at the nub, is usually a sign of the retaining barrel not being lubricated and not rotating when you pull the lever, bending the cable and causing it to fail prematurely. (never lube the cable itself)  I think I'm going to lube my barrel right now while I thinking about it.  Thanks!

OK, I will make sure I lubricate the retaining barrel.  Is that something you do periodically as well?  Thanks
Title: Re: Snapped Clutch Cable
Post by: BobR on May 05, 2012, 11:08:52 PM
i carry a peice of aircraft cable and brass cable ends in my bung... when my clutch cable broke i simply slid the aircraft cable down the existing jacket... slid the cable ends in the clutch levers and tightened the cable ends down on the cable... i rode like that for about 20,000 miles before finally swapping out cables...

i can scrape up photos if you wanna take a look... all parts can be had at the hardware store for about 5 bucks total...

j o

I would definitely like to see pics of this, if  not too much trouble.  Sounds like a great idea.  thanks...
Title: Re: Snapped Clutch Cable
Post by: mystic red on May 05, 2012, 11:55:16 PM
i carry a peice of aircraft cable and brass cable ends in my bung... when my clutch cable broke i simply slid the aircraft cable down the existing jacket... slid the cable ends in the clutch levers and tightened the cable ends down on the cable... i rode like that for about 20,000 miles before finally swapping out cables...

i can scrape up photos if you wanna take a look... all parts can be had at the hardware store for about 5 bucks total...

j o

I would definitely like to see pics of this, if  not too much trouble.  Sounds like a great idea.  thanks...

yellow on a blue background.........
Title: Re: Snapped Clutch Cable
Post by: johnny on May 06, 2012, 12:31:27 AM
most ace hardware stores carry two types of hillman fastners brand what they call cable stops... thats what they call them anyway... they are generally used on older lawn mowers and other vintage power equipment as choke and throttle cable ends...

the hex unit fits perfectly into the hole on the handle bar clutch lever... the round one fits perfectly in the lower clutch lever down by the swing arm...

i would getts a couple of each and a couple lengths of the small diameter stainless aircraft cable they sell at ace... its the stuff on the red rolls... make sure its small enough to sit the holes in the cable stops...

warning... when in the bung... moto vibrations will back the screws out of the brass ends and unravel the ends of the cable... i screw the screws in tight so they wont back out and wrap the ends of the cable with electrical tape...

(http://i12.photobucket.com/albums/a247/michylyn/RideTales/PICT0001.jpg)

napa has these... im not sure if they will work... i think the diameter may be too large to fit the holes...

(http://i12.photobucket.com/albums/a247/michylyn/RideTales/PICT0006-2.jpg)

j o
Title: Re: Snapped Clutch Cable
Post by: Snowy on May 06, 2012, 05:11:28 AM
I went for overkill and have a second OEM cable already in situ next to the existing one so I can just swap them over if it fails.
Title: Re: Snapped Clutch Cable
Post by: thebob on May 06, 2012, 08:04:04 AM
Those solderless nipples are often used on Karts...

http://www.gokartsupply.com/thcable.htm (http://www.gokartsupply.com/thcable.htm)
Title: Re: Snapped Clutch Cable
Post by: mystic red on May 06, 2012, 10:09:04 AM
I went for overkill and have a second OEM cable already in situ next to the existing one so I can just swap them over if it fails.

I have my old one in the bung but Johnny's and your method would get you back on the road quicker. :yes
Title: Re: Snapped Clutch Cable
Post by: Inge K. on May 06, 2012, 11:10:08 AM
The OEM clutch cable is a very reliable part, if you keep the nipples lubricated.
On my oldest K I have changed it one time during 26 years of ownership/+200K km.
And it wasn`t because of that it did snap, it just was stiff to operate after years in service.

Inge K.
Title: Re: Snapped Clutch Cable
Post by: DRxBMW on May 06, 2012, 05:21:23 PM
I went for overkill and have a second OEM cable already in situ next to the existing one so I can just swap them over if it fails.

I have my old one in the bung but Johnny's and your method would get you back on the road quicker. :yes


MotobricK store may be in order ?  I would buy a clutch repair kit.

FWIW, I've never broken a K clutch cable yet. Honda Moly 60 grease applied with a q tip every six months on both barrel ends is the mantra. 

Wunderbar Sping-Fling event sponsored by the Honda club this morning. Ha, I was the ONLY friggin BMW in attendance, piloting the GS too boot :bmwsmile :bmwsmile



Title: Re: Snapped Clutch Cable
Post by: mac on August 27, 2012, 07:50:06 PM
Where exactly do you all apply lube to the "nipples?"
I'm assuming between the end of the ferrule and the seat in the barrel adjuster at the lever end, and between the ferrule and the seat at the clutch end.
I'm not quite sure how this prevents a failure...why does the ferrule/housing need to be allowed to rotate?
Title: Re: Snapped Clutch Cable
Post by: frankenduck on August 27, 2012, 08:51:34 PM
why does the ferrule/housing need to be allowed to rotate?

Because the direction of tensile pull changes relative to the clutch lever when you pull in the clutch.  If that ferule isn't rotating freely and easily then you are bending and fatiguing that end of the cable every time you pull in the clutch.
Title: Re: Snapped Clutch Cable
Post by: Photog on August 28, 2012, 07:50:34 AM
I have found that super glue works well to keep the ends of a cut cable from fraying. Clean it with a fast evaporating solvent (brake cleaner is ideal), then put a drop or two of glue onto the end of the cable so that it wicks into the strands.
Title: Re: Snapped Clutch Cable
Post by: mac on August 28, 2012, 01:26:14 PM
why does the ferrule/housing need to be allowed to rotate?

Because the direction of tensile pull changes relative to the clutch lever when you pull in the clutch.  If that ferule isn't rotating freely and easily then you are bending and fatiguing that end of the cable every time you pull in the clutch.

Ahh! A different axis of rotation than I had been picturing. If I understand correctly, this is about "bending" perpendicular to the cable axis, rather than twist (as i had been picturing) along the cable axis. I can't remember: are these nipples kinda spherical on their ends to allow this "bending" motion?
Title: Re: Snapped Clutch Cable
Post by: frankenduck on August 28, 2012, 01:59:26 PM
The end of the clutch cable goes into the ferrule which is cylindrical.

The picture below shows why the ferrule needs to turn freely so that it's not repeatedly bending and fatiguing the cable.  The drawing I did is perhaps a bit exaggerated but you get the idea.  It's only a slight bend to the cable but do it enough times and it will eventually wear out and snap the cable.
Title: Re: Snapped Clutch Cable
Post by: mac on August 28, 2012, 02:15:30 PM
Title: Re: Snapped Clutch Cable
Post by: mac on August 28, 2012, 02:31:46 PM
This post
http://www.motobrick.com/index.php/topic,2533.0.html (http://www.motobrick.com/index.php/topic,2533.0.html)
may have added to my confusion. When people are referring to the "barrel", I was thinking of what we call the "barrel adjuster" on pedal-bikes.

I'm now thinking that people may have been referring to the cable stop itself, which I suppose is barrel shaped...
Title: Re: Snapped Clutch Cable
Post by: frankenduck on August 28, 2012, 03:40:19 PM
People use both names for it.  It is cylindrical.  The parts catalog name for it is a "nipple holder." :yow
Title: Re: Snapped Clutch Cable
Post by: RobP on August 28, 2017, 10:11:43 AM
Well, I wish I had read this thread earlier -  mainly the part about lubing the nipple connection on the cable ends.   I had replaced my clutch cable about 2 years - 5K miles ago and it broke during my ride last Saturday.  Had to use the kill switch to keep from getting launched into the highway intersection.  I pushed my bike about 100 yards to a farmer's yard for safekeeping while I handled the logistics for a recovery operation that took most of the day.
Title: Re: Snapped Clutch Cable
Post by: Martin on August 28, 2017, 04:51:40 PM
Iv'e added a grease nipple to my clutch arm. The occasional shot of grease keeps it lubed and stops water  and crap from entering. There has been a lot of debate over lubing OEM cables some do some don't. I also occasionally lube the clutch cable with a PTFE lubricant called Triflow which does not degrade the Teflon liner as does some other lubricants. Triflow is sold in bicycle shops for chain and cable lubrication. These modifications along with lubing the lever ball ends I believe have allowed my Brick to be still running the original 25 year old cable.
Regards Martin.
 [ Invalid Attachment ]
Title: Re: Snapped Clutch Cable
Post by: johnny on August 28, 2017, 04:58:41 PM
greetings...

with all that lubeing... you oughtta start a new site called lubetube...

j o

Title: Re: Snapped Clutch Cable
Post by: Martin on August 28, 2017, 05:06:33 PM
JO embrace the way of the lube. Lube is your friend especially if you end up in jail, a place where I have no intention of going.  :yow
Regards Martin.
Title: Re: Snapped Clutch Cable
Post by: Motorhobo on August 28, 2017, 05:58:54 PM
I pushed my bike about 100 yards to a farmer's yard for safekeeping while I handled the logistics for a recovery operation that took most of the day.


That happened to me recently -- was it not a good place to 'bump' start the bike in 2nd with the start button and battery power? I did it recently, but then again, where I live there's nothing but farmland and no traffic to speak of. I was able to speed match to shift, no problem, got it in and out of all gears and got it home trailer-free. If you had a lot of stop and go, then I guess that's another story...
Title: Re: Snapped Clutch Cable
Post by: RobP on August 30, 2017, 08:37:41 PM
RE:  w'"was it not a good place to 'bump' start the bike in 2nd with the start button and battery power?"


I tried, but I'm not practiced in no-clutch shifting.  I was out in wide-open farm country when the cable broke, but would have had to bring it back to suburbia with more than a few stop lights and busy intersections along the way.