I thought it would be worth posting some hints towards getting Campagnolo Delta brakes up and running. The Delta Brake Blog does a good job of identifying the various versions, and this is a good primer. There is more conversation online about this obsolete jewel of a brake than I had imagined.Comments include the usual tip to set them up further from the rim than you normally would, replacing the now-ancient brake pads with this or that pad and/or holder, being sure you have the correct brake lever, etc etc. One thing I wasn't aware of was how much better they worked with the non-aero routing, as I would NEVER set them up that way.
My latest and greatest tips, after setting up three sets of them in the past month or so, involves the cable and housing.
Now I always run the freshly-cut housing end on the grinding wheel, to get it nice and flat. If possible, I suggest compressionless housing but, in the case of a recent Somec build, when only that neon pink 1980's housing will work... run NOKON-style link housing from the brake lever and splice it to the old housing just under the end of the bar tape with a special female-female ferrule. Jagwire calls it a "Double Ended Connecting Ferrule".
Next, I really think the cable is part of the solution here. Campagnolo spec'ed a very stiff cable, one that likely would sell for way too much money on eBay here in 2019. That said, I was able to overcome the horrible crunching sound at the bar not only with the NOKON housing run, but also by using a cable that has been drawn or polished to have a smooth outer surface. My memory is that Quality Bicycle Products (QBP) was the first to market a brake cable as such, but that now they must be commonplace. Now it seems the Jagwire Pro Road is the model currently marketing this feature, even though my knowledge of specific cable finishes is lacking and half of the commonly-found cables could be considered smooth.
For archive purposes, I think it's wise to publish my friend Steven's post from Bike Forums, which is likely the most level-headed and well-informed take on the subject...
"Some of the most important considerations to take into account are: proper distance from the rim (set them up too close and they will never reach the sweet spot of the progressive braking power), proper brake cable (many people simply use any old brake cable, whereas Campagnolo specced a thicker and firmer cable than what was most commonly used by other manufacturers, this is very important as many cable are perhaps too stretchy for use in delta brakes), the height must be correct (delta brakes can be adjusted up and down, if you do not have them set up at the ideal height, you will lose considerable power), new brake blocks (if the brake blocks have not been switched out by now with fresh rubber they are guaranteed to be sub-par. The delta blocks from the 80's seem to have been made of a rubber that hardened faster than many others), routing of cables (if you do not route them well enough you can lose a substantial amount of power, more so that with modern brake systems), length of cable (because the cable does not really have any appreciable room beyond the fixation nut, you have to get this spot on, ideally after having soldered the end to prevent any splaying and fraying of the cable end), lubrication and cleanliness (it is all too common that dust and rubber particles get inside the brakes and "gum" up the mechanisms; just because the mechanisms are covered up does not mean that they do not need to be serviced and lubricated.) Look after all these things and they work as well as all but the very best brakes designed pre-1985. If you are comparing them to modern-day brakes that is another thing."
