Friday, April 19, 2024

Clutch cable won't work? Here's a fix

Cotton swab through hole in gearbox back.
Cotton swab shows path of Royal Enfield clutch cable through back of four-speed gearbox.

 "Eeeewwwwwwww," my wife groaned, as she picked up my helmet from the sidewalk and put it into our car. 

"That is one soggy helmet!" she said. 

No surprise. 

I had just pushed my 1999 Royal Enfield Bullet about a mile, with my helmet on because I had no other place to put it besides on my head. 

I had considered abandoning my helmet and returning for it later, but figured that if she came in the car and got it she could also bring me some water to drink. 

I would need the water. I still had another mile to push to get home. Luckily we live in Florida, where there are no hills to push up. 

Several people stopped to offer help. Did I need gas? Nope, got plenty. Did I need to borrow some tools? Nope. I have a full kit on board and could fix the problem -- if I only knew what it was. 

It all started with a broken clutch cable. (This time the little nub on the end of the cable broke off at the lever. Usually it's the nub on the gearbox end that breaks off.)

Luckily I carry a spare cable and all the tools needed to swap it in. I've done it on the side of the road before. (My spare cable is extra long, so it need not be threaded through the nacelle, but can arch over the handlebars.)

This time, however, the moment I set off with my new cable installed, the clutch lever went right to the handlebar and the motorcycle stalled. Once again I couldn't disengage the clutch!

I knew the problem couldn't be another broken clutch cable, so soon. I'd need time in the my garage to diagnose this problem, and that meant a two-mile push home! Ugh.

Thanks to the four-speed Bullet's neutral finder lever I was able to put the gearbox into neutral.

And so the long, hot push began.

The next morning I began taking a closer look. Indeed, the new clutch cable was intact.

The trouble was that the cable could not operate the clutch because its whole end had been pulled inside the gearbox. To work, the outer cable must stop at the gearbox wall and allow only the inner cable to respond to the handlebar clutch lever.

View of hole in gearbox from back side.
View from behind of hole that must grip outer cover of clutch cable.

Removing and replacing the cable was no help: the first pull on the handlebar lever once again yanked the cable through the hole into the gearbox. Obviously, the hole had grown just big enough to allow the fat end of the outer cable to pull right in.

I'm stumped on how to make that hole smaller. All I could think of was to put a washer on the outer cable to stop it from being pulled into the hole.

It's a bodge, not a perfect fix. The washer barely grabs the shallow ridge at the cable end, and in doing so it holds the cable slightly proud of how deeply it should be held in the hole.

Gearbox end of cable with washer fitted.
Washer will keep all but narrow tip of outer cable from entering gearbox hole. Note the shallow "shoulder" of the cable that is supposed to prevent it going into the hole, but doesn't. It will keep the washer in place, I hope.

The effect of this is to shorten the reach of the inner cable. It is just slightly shorter, but enough so that I had to leave off the cable adjuster at the lever end to let it reach the ferrule that holds it at the handlebar lever.

I'll replace the adjuster when the cable has stretched enough.

The photos here explain how I made my "fix."

Washer held in vise has flat side filed into it.
I filed a flat side onto the washer to better fit near the gearbox hole.

The washer I used has an internal diameter of 3/8 inch (8mm). It must be rather a common size as my spare parts bin is full of them. Since replacing the cable roadside will undoubtedly result in the washer falling off and disappearing I put a package of extra washers into my on-board toolkit for next time.

But there IS a better solution: In "My Cart" at Hitchcocks Motorcycles is clutch cable part No. 142453A, for Bullets made before June, 1999 with the Magura handlebar controls. Allan Hitchcock suggested it in response to a question from me.

In an email, he wrote of this cable:

"There is the top hat outer cable ferrule which locates in the case of the gearbox (the originals had a crude domed ferrule). This looks to have a bigger diameter shoulder to the ones in your photo, which will prevent it pulling through."

That's just exactly what I need. 

Finally, I'd like to thank the charming young sales associate at the business whose parking space I used to initially replace the clutch cable. She graciously offered me a bottled drink, which I had the affrontery to refuse, so confident was I that my repair was complete.

How badly I suffered with thirst in the blocks before my wife came to the rescue with a thermos of water. Serves me right.

6 comments:

  1. Mike Bolasna4/20/2024

    You must be in Great Shape to push your bullet for a mile.

    Great Fix

    Thanks

    ReplyDelete
    Replies
    1. Thank you. I am no muscleman. But I found I could push it like a bicycle, by walking alongside and holding the handlebars. Once in motion it tended to roll pretty easily. The only problem was the danger of dropping it; I tried to keep it carefully under control and tilting toward me, if at all, not away from me.

      Delete
  2. Tim Lewis4/20/2024

    I would have counter bored the hole in the case. Then made a sleeve that would bush the hole enough to stop the cable where you wanted it to. By the way, 8mm is almost exactly 5/16. Great story, keep riding

    ReplyDelete
    Replies
    1. That would be a nice repair, but I'm not skilled enough to not screw it up. Based on what Allan Hitchcock says, the original cables had a washer like top-hat or domed ferrule to prevent the very problem I experienced. The cables I have bought in recent years, though, have only that vague shoulder to their design, not enough to prevent what ultimately did occur. I think my bodge basically reproduces the original intention. Thank you for the correction on size. The washer fits loosely so, just to keep it on while I was pushing the cable end through the frame, I put a little dab of super glue on it.

      Delete
  3. Anonymous4/25/2024

    Always check that you have stated Magura when ordering cables. I was luckily told that before I ordered and a few years ago, same as you, at the roadside, changed it out, but all was fine. good job to as I needed to go up a pretty steep hill, pushing was not an option!
    (Scaleyback - forgot my log in!)

    ReplyDelete
  4. Anonymous4/30/2024

    I had the same thing happen on my '99. The solution I found was to start the bike in neutral, then straddle the bike using the waddle to get the bike up to a speed of 5 or 6 mph, then slip it into 2nd gear and chug away home. Thanks for the tip about the clutch cable part No. 142453A, that explains a lot.

    ReplyDelete

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