You don't say what brand FD. I had the same concern, but the Simplex rod FD on my 1954 Duravia shifts a 50-36 quite well. So, at least for Simplex, I don't think the tooth spread is a significant problem. On the Simplex, however, the range of movement is limited by the fact that the design has the inner travel of the top of the rod stopped agianst the right side of the seattube, so I don't think this design can shift a triple. Another thing I found a little tricky was adjusting the FD so as to shift onto the large ring without overshooting and dropping the chain outside the large ring. There are no stop screws like a cable-operated FD, so you have to move the cage in and out on the rod. But overall, these rod RD's shift a wider tooth range than most people expect they would.
Regards,
Jerry Moos
Big Spring, Texas, USA
> From: Michael Allison <cyclo_one@verizon.net>
\r?\n> Subject: [CR] info needed on Suicide derailleur
\r?\n> To: classicrendezvous@bikelist.org
\r?\n> Date: Monday, December 7, 2009, 10:52 AM
\r?\n>
\r?\n> I'd like to use a rod operated front derailleur on my 1958
\r?\n> Holdsworth restoration. Does anyone have experience on how
\r?\n> well they handle large chainring differences? Will they
\r?\n> shift the chain on a 46/32 (or smaller inner) combination?
\r?\n>
\r?\n> Michael Allison
\r?\n> New York, NY