In reply to MeMeMe:
> They sound good but they are a lot weaker than normal rocks (4-6kN compared to 7-12kN).Do you know if this is due to the single wire or to the narrower head?Or something else?
> Just wondering if you could have the advantages of the smaller profile and single wire without the disadvantage of the lower breaking strain if you used heavier materials?
As the designer of Superlight Rocks hopefully i can answer your questions...
The Superlight Rocks are weaker than std Rocks basically due to the unique way they are made - something which came about due to the way we manufacture Zero cams.
The problem had always been with aluminium that to create a small (micro) nut has been impossible because you cannot solder Aluminium (nut) to Steel (wire) - thus in the past all aluminium nuts had to have a loop (two strands) of cable running through them which limited the size they could go down to - especially width wise..
But with the new Zeros cable design this was solved as a small steel collar is soldered to a single cable (creating a 'stop') and for the Superlights is then pushed through what is essentially a sawn in half rock...
And since it is a single strand this gives the ability to finally have a much narrower head in aluminium and this gives amazing placement possiblities - see reviews...
However, it is the strength of this soldered ring which is the limiting factor - and if you will note the Superlight Rocks give the same strength as the Zeros which use the same size cable...sizes 1 - 4...
And as for using 'heavier' materials - if by that you mean larger materials - and yes you could but then you would have a larger heavier nut, which would defeat the object...a non micro micro nut??
As the designer i envisaged the Superlights to be used in exactly the way Jonathon and others (I used the superlite wires on north stack the other dayand they were ace - James MacHaffie)have enjoyed them - as an addendum to a regular rack and as a specialist tool to give more options for very little weight.
Nuts of this size always have their limitaions and should be used with care - but as i think someone else says 'it's better have it than not'...and as for Andy K saying to not use WC or DMM micros then it's maybe becasue he's not been on the sharp end of an E4 E5 or E6..