On average the
outer cable length given in this list should work for all rigid girder BSA M20's.
When the correct cable length is used it's easy to see how the cable
original would have been situated on the bike, it fits just in one way and
works with great ease. In general the
length of the outer cable will always be usable no matter if all components
are original or not. The inner cable needs to be made to the right size
depening on the length needed. Part numbers are taken from the 1947 parts
list length remains the same for all years.