Cotter pin alternative for control rods |
Some of the earlier motorbikes have many small cotter pins for locking the rod ends of their numerous control rods either, when the rod has a bent end, simply by inserting the cotter pin through the rod end itself (Harley Davidson) or, when the control rod has a forked end, indirectly, by locking the separate connecting pin.
When carrying out maintenance work on such a motorbike
a lot of time is wasted and damage risked in trying to take out the cotter
pins, not least because the cotter pins are almost always in positions
which are very difficult to reach.
However, the smallest of these existing clips that could be obtained was still too big to be used as a replacement for cotter pins in control rods. Moreover the smaller "R"-clips are not very effective and are liable to come loose, mainly because the risk of deformation of the circular spring part during insertion is high.
Nevertheless such a clip appeared to represent a practical alternative if made small enough whilst also providing improved clamping force and reduced risk of deformation during insertion.
The latter problem was solved by modifying the circular spring part to form a helically wound spring, which allows high flexibility and at the same time improved clamping force, even for very small diameters of the spring part. In view of the high clamping force required, high quality spring wire was first used for manufacturing the clip, but better results were obtained using safety pins which are moreover readily available in many different sizes.
If nickel plated safety pins are bought then simple
cutting and bending is enough to provide a clip all ready for use! I also
found that the nickel plating does not chip off if round nosed pliers are
used for bending.
Bending the clip legs into any shape and, when finished, manipulating the clip into the required position on the motorbike is quite easy when using round nosed pliers for holding the helically wound part of the clamp.
Four varieties are shown below, of which in particular Nos. 3 and 4 gave excellent results. Other possibilities are left to the imagination of the keen restorer!