THE THROTTLE CABLE

Whilst checking through the control cables I discovered that I was short of a throttle cable.  You might have thought that it would have been very obvious but as I said non of the cables were identified and none were terminated.  I guess I was bewitched by their nice shiny grey covers.

I got on to my new found friends at Cassa Lambretta, Danny (the LD expert) and Lee.  In no time at all I had a new throttle cable for only £2.50 plus P&P - bargain.  I also took the opportunity to buy two trunnions for the ends of the gear change cables (£2.08). I wonder where those bit went and why they were lost.

This nipple should be rotated by 90 degrees

I ran the cable through the frame on the correct rout.  My first problem was that when came to fit throttle end I had difficulty in getting the nipple to sit nicely in the twist grip.  No matter what I did the nipple always wanted to be at right angles to the recess in the twist griip.  I tried twisting the nipple to the position I wanted but it only sprung back the its original position.  If I tried to twist the nipple further, say through 120 degrees, the nipple would jump 180 degrees and so I was back in the same position.  I think there must be something wrong with the inner itself, a kink?

12 mm short

Having finally got the cable into the twist grip with the nipple sitting correctly in its recess and the assembly clamped tight on the handlebar I turned my attention to the other end.  Oh dear, it looks a bit short. (perhaps I said something a  little stronger than that)

I re checked everything  but the inner cable was still short.  Having slept on it I had two options, buy a new able or shorten the outer sheath.  I think the first was the best option because it might clear the nipple problem but I felt I could wait until I sent my next order to Danny.  In the mean time I would just have to shorten the outer by 12mm.  Easier said than done.

Firstly the end ferrel had to be removed.  This is swagged onto the end of the cable and can't just be pulled off.  By carefully cutting round the ferrel (using a junior hacksaw) above the swagging it was possible to remove it and cut through the swagged bit to remove that.  

Now for the outer.  Because both ends have crimped ends it is not possible to remove the inner cable.  This means that when cutting through the outer you have to be careful not to cut the inner cable.  By using the hacksaw again and carefully working my way round the outer progressively cutting into the wrapped steel outer it was possible to separate the end 12mm.  Now it only remained to cut off this short length, again without damaging the inner cable.  By holding the short length in a vice it was possible to cut along its length and finally produce a series of rings that then could be removed.  The inner low friction sheath was easy to remove with a knife.  With the outer/inner cable shortened I was able to glue the end ferrel back over the end of the outer sheath.  Job done, almost.

The cable fitted as I think it should and the carb throttle leaver operates with the with the twist grip.  BUT .....
I'm still not happy with the twist grip end nipple.  It was difficult to assemble and I think that because it is constantly trying to twist 90 degrees it will eventually do and then there is a change of failure.  Knowing my luck that will be at some most inconvenient moment.  I had a try at unsoldering the nipple before I realised that it was crimped onto the end of the cable.  In my day they were always soldered and I could have rectified the problem.  I will have a talk with Danny before ordering another cable.  I think it essential that the twist grip end nipple sits correctly and the length is right.

And now for the gear change cables.