Originally Posted by
Barchettaman
Morning all,
I’m pretty sure it will work, but just before I buy and install it:
will a new 4700 front shifter pod work nicely with an older 10-speed 105 front derailleur?
I am aware that there are compatibility issues with the newer Tiagra stuff and the pull ratio on the rear, but there doesn’t seem to be any information about the front!
thanks in advance
(It’s for a flat bar road bike conversion. 2x9, 10-speed crank and chain)
I understand that Shimano also changed the geometry of their road double front derailleurs about the same time, and that their newer double FDs are
not compatible with older shifters for much the same reason (different actuation). However, I've also never been able to find any hard data confirming or refuting that. I haven't tried it myself, so I don't know for certain.
It's also my understanding that Shimano's few newer road triple FDs (primarily the Tiagra 4703 - I don't think the 11-speed Ultegra or 105 groupsets ever released a triple FD) do
not use the new geometry (and thus the newer FD pull ratio), and thus should be compatible with older shifters. Same issue here: I've not been able to find any good data that would confirm or refute this, either. For some reason, tech info on FD pull ratios seems to be unavailable.
Like you, I'd hate to buy a shifter or FD and find out I'm the first "guinea pig" for initial testing.
If you're converting to 10-speed, you might want to consider using a Tiagra 4700 FD - or sticking with an older double front shifter if you plan to keep the 105 FD - to be safe.
The 4700 FDs are readily available and aren't terribly expensive. I did a quick check on eBay and used braze-on FD-4700s can be had as low as $26 US (including shipping to a US address) plus applicable taxes.
Best of luck.