What exactly does it do?Me again.
There's a knurled adjuster inside the hand guard, near the lever pivot -
Excuse the rusty bit, won't you?
It's part no 20 on this fiche -
Mmmm I hope this doesn't sound rude Lutin, but have you ever used ACF50....
Ummmmm pretty sure it does adjust the span by pushing the lever away/toward the business end of the master cylinder. Certainly seems to on my TA and the Vara anyway. Could be the thread is knackered and turning the knurled adjuster is having no effect .Mmmm I hope this doesn't sound rude Lutin, but have you ever used ACF50....
The dial control doesn't adjust the span, it just adjusts at what point you start feeling the brakes start to bite.
Some people might prefer the brakes working earlier, some people might want to have more of a handful before braking really kicks in. Basically it controls the distance the lever is pulled back before braking is felt, but does not affect span.
How about a dog leg lever?