Are parallel v-brakes fixed distance? [Avid Arch Rival 50] OK, this is naive question, but I have to be 200% sure :-)

If you compare the regular v-brake against parallel v-brakes as Avid Arch Rival 50:



the one thing which is always ignored is the way you can change the distance between pads. In the regular v-brakes you change the distance with the cable, more loose means more distance between pads.

But with parallel v-brake the distance is fixed, so loosening the cable does not change a thing, it just adds a dead cable section.

This influences the pads and the wheel rim you can select -- more fat pads or slightly wider rim and you have a problem.

The question is -- am I right with the fixed distance in such v-brakes?

UPDATE: fixed means -- there is some distance, predefined, and you can narrow it, but you cannot increase it. Let's say you are on the ride and you hit something hard with wheel. The wheel needs trueing. With regular v-brakes you just loose the cable to get home. With parallel v-brakes loosening cable does not help.

Photo comes from Avid Arch Rival 50 Review at GearReview
iirc - the Arch Rival V-brakes are described as parallel because the brake block surfaces are always parallel to the rim braking surface at whatever distance from the rim. This in theory improves braking.

Other than this - they function the same as a normal V-brake in that the arms act as levers to apply the brake blocks to the rim surface.

Adjustment may be a bit more picky - in that as the cable is loosened and the braking arms move outward - it will raise the brake blocks to keep them parallel to the rim. Therefore, to get the pads further from the rim - you may have to slacken of significantly more tension than with traditional V-brakes.
You may have to undo the cable entirely to slacken enough.