Replacement front derailleur

Hi,
I was about to install a Tiagra 4500 groupset to a frame I have here. The problem I have is that the front derailleur is a band on type with a 34.9 band. I need a 31.8.
Other than a FD4500 front derailleur, and as I will invariably be trawling the bay (or other sites) looking for a replacement, what other series are compatible with the ST4500 levers?
I'm thinking....
FD4600
FD3400
I've seen FD4503 available but I'm not sure if there is a fundamental physical difference between that of the triple and the double? Any advice greatly received.
I was about to install a Tiagra 4500 groupset to a frame I have here. The problem I have is that the front derailleur is a band on type with a 34.9 band. I need a 31.8.
Other than a FD4500 front derailleur, and as I will invariably be trawling the bay (or other sites) looking for a replacement, what other series are compatible with the ST4500 levers?
I'm thinking....
FD4600
FD3400
I've seen FD4503 available but I'm not sure if there is a fundamental physical difference between that of the triple and the double? Any advice greatly received.
0
Posts
https://www.ebay.co.uk/itm/Shimano-Fron ... .l4275.c10
Google or eBay this - Shimano SM-AD17 Front Derailleur Clamp Band Reducing Adapter - 34.9mm to 31.8mm
Your LBS probably has a box full of spares.