Click, shift, done.
LOL. There, we said it -- the first time ever on the Competitive Cyclist website. LOL. Why are we LOL-ing? Because we know that's exactly what the mad engineers at Shimano are doing about the Dura-Ace FD-7900 front derailleur.
It's just a front derailleur -- what can be so amusing? It's this: When Shimano's arch-nemesis SRAM unveiled their much-ballyhooed Red component group in fall 2007, one of its most-hyped attributes was the fact that the left Red Doubletap lever (in contrast to SRAM Force and Rival) allows for front derailleur trimming. It has a micro-shift to it, which allows you to cross chain in gears like a 53x21 and eliminate noisy front derailleur/chain rub. And this was a fine enhancement, so long as you didn't dig too deep into the details (e.g. Red doesn't allow for trimming when you're in the small chainring -- so you're SOL if you're in a 39x13. Cross-chaining in the small ring is noisy as hell. Another fact, of course, is that Shimano has offered front derailleur trim in the STI lever since, like, forever).
What's funny (or at least interesting) is this: The great innovation with the Dura-Ace FD-7900 is that Shimano has eliminated the need for front derailleur trimming. SRAM hasn't yet figured out how to provide it, and suddenly Shimano has made the need (in a Dura-Ace drivetrain, anyway) obsolete. Thanks to the fresh design of both its cage profile and the linkage, you can cross-chain to your heart's content. You won't get chain rub, so you won't need to micro-shift the noise away. Sure, 53x25 and 39x11, etc. are usually unwise gears to be in -- they put excessive wear on your drivetrain, and they have loads of mechanical drag. But, then again, at crunch time on race day, your pain-addled, oxygen-starved brain isn't optimally situated for thoughtful shifting decisions.
The redesigned and widened linkage combined with the optimized spring tension reduces the shifting force required to move between chainrings. These shifts typically happen under a decent bit of load -- exactly the situation Shimano had in mind with the Dura-Ace FD-7900. Many folks say the most dramatic shifting improvements between 7800 and 7900 are with the front derailleur, not the rear.
The Shimano Dura-Ace FD-7900 front derailleur is available in braze-on, 28.6mm clamp, 31.8mm clamp, and 34.9mm clamp. It is compatible with the Shimano Dura-Ace FC-7900 and FC-7950 cranksets and Shimano Dura-Ace CN-7900 chain. According to Shimano it is not compatible with the Dura-Ace 7800 series crankset and chain.
Share your thoughts
I have the Shimano Dura Ace bar end shifters...
I have the Shimano Dura Ace bar end shifters on my Cervelo P3 Tri Bike. It has an Ultegra Front Derailleur. The bar end shifter for the front is a friction shifter, rather than a clicky type. Since the 7900 is supposed to have this awesome no-trim feature on the large chainring, how different will it shift for me versus the 6700 given I have the fricton type shifter?
Should be good to go - no worries, just more awesome shifting :)
- Gender: Male
- Familiarity: I've put it through the wringer
It's a nice derailleur, works just fine.
Will this work with Shimon 5700 105...
Will this work with Shimon 5700 105 shifters?
Should work OK ;)
I have the Di2 Dura -Ace set up on my...
I have the Di2 Dura -Ace set up on my Cervello using the FD-7970 front derailleur. I wanted to change my rear cassette to a 12-27. Do I need to change the derailleur or will it work without any adjustmants just changing the rear sprocket? Thanks
Just found out that it was the rear derailleur RD-7970 that is the factor and apparently it will work with the 12-27...So thanks anyhow.
Will the 7900 front and rear derailleur...
Will the 7900 front and rear derailleur work with ULTEGRA 6700 SHIFTERS SHIFT LEVERS ?
Of course! No issues at all, just make sure if you're running a double you're using the right the shifters and front derailleur; same story if you run a triple. Make sense?
The front derailleur is just as smooth as the rest of the 7900 series drive train and feels great.
will the 7900 front derailleur work with...
will the 7900 front derailleur work with 7800 shifters?
Not well, the Spring is much lighter in the 7900, it will shift fine just feel really light.