mynameistaken

This is supposed to be a 105 5700. However it doesn't look like the ones on Shimano's website. I don't see any markings on it either. Can someone please verify that this is a 105?

desertdork

Possibly a R770. The backside of the inner cage plate should have the model # on it, e.g. FD-R770.

The R770 & R773 FDs were designed for 10-sp drivetrains in conjunction with Shimano's SL-R770 flat bar shifters. Is this a hybrid bike?

mynameistaken

Yes its a hybrid bike, and yes I looked where you said and it is a 770. Will a 105 work with flatbar shifters?

desertdork

I've not tried those 770 shifters with a 105 derailleur, but the claim by Shimano is that the two will be incompatible. Does your FD-R770 need to be replaced?...or is this a type of upgrade? I ask because the 770 is a high quality derailleur.

mynameistaken

Actually you are right again! The 770 does at least cost more than the 105 a few places I checked. The reason I asked is because the bike I just purchased was advertised to come with the 105 5700. It works fine so I will leave well enough alone.

Thanks!!!!!

JiveTurkey

That FD is a flat-bar road FD. It allows you to use flat-bar/MTB front shifter with larger road chainrings. Don't replace it with a regular road FD, like the 105, or its cable-pull ratio won't match to your shifter.

desertdork

FWIW, in your comparison, you shouldn't really judge the quality difference by the item price. I suspect that Shimano sells countless more 5700 FDs than R770 FDs, and either a higher price or lower profit will come with the smaller production. Regardless, the R770 I had was functionally and cosmetically equal to my Ultegra.