Originally Posted by
HillRider
Yes, my 1980's Sun Tour ARX FD handled a 46/42/26 triple crank just fine as it's inner plate was shallow enough.
However, unless the OP can find one of these and is using friction front shifting the suggestion isn't of much use. The original Sun Tour has been out of business for many years and their old components are now pretty much rare collector's items. None of these vintage FD's were intended for index shifting either.
However, OP said he is using friction and both Vx (including a NOS) and Cyclone FD's are currently listed on Ebay. I don't suppose either is much more difficult to obtain than a new derailleur.