I don't know how many of the intended functions of the long dropouts were factors but in the design but they certainly are handy in a number of ways. They are helpful when "pushing" a Campagnolo Nuovo Record rear derailleur to handle a 28t large cog without the pulley bumping on the teeth (may have to remove adjusting screws altogether). Also useful to accomodate larger tires but I don't care to have to insert a wheel with the tire uninflated. Certainly useful when converting a bike to a fixed gear.
I've a number of frames with missing or bent dropout adjusting screws. While they must be handy in a racing environment to allow a fast wheel change without the need to play around with centering the wheel in the rear triangle, I don't consider the screws to be essential. They won't do anything to maintain adjustment because if a quick release slips, the wheel will go forward away from the screws.
Haven't experimented with the difference in feel from front to back but the long dropouts certainly provide the option of tightening (or stretching) the wheelbase by modest amount.
Charles T. Young
> So, what is the function of dropout adjusting screws? Even in the long
> dropouts, the springs take up so much room that there really isn't much
> room for adjustment. And what difference does the adjustment make? I
> doubt if anyone would notice the change in wheelbase. The whole long
> dropout/long adjusting screw has always baffled me. It always seemed
> like the long dropout was just a leftover from the Cambio Corsa or
> something like that.
> Louis Schulman
> Tampa, Florida, where I was able to ride between storm clouds for a
> nice 50-mile tour around the Bay on my 1973 Ron Cooper (which has the
> long droupouts and adjusters, fwiw)