For a steel frame, a spread of 126mm to 130mm should be no problem at all.
I spread my UO-8 from 120 to 123mm (ultra-6) and my Capo Modell Campagnolo from 120 to 126 (standard 6-speed), all without any issues whatsoever.
Electronic shifting is the one form of post-friction transmission control which actually interests me -- let us know how the project goes!
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"Far and away the best prize that life offers is the chance to work hard at work worth doing." --Theodore Roosevelt
Capo: 1959 Modell Campagnolo, S/N 40324; 1960 Sieger (2), S/N 42624, 42597
Carlton: 1962 Franco Suisse, S/N K7911
Peugeot: 1970 UO-8, S/N 0010468
Bianchi: 1982 Campione d'Italia, S/N 1.M9914
Schwinn: 1988 Project KOM-10, S/N F804069