2009 Da

Peter@vecchios

http://www.competitivecyclist.com/za/CCY?PAGE=WHATS_NEW

Great, back to future with DA...7900 not compatible with 7800 ders.

alfeng

Thanks for the heads-up on the new DA components ...

FWIW. I've been hearing/reading about the lack of compatibility about Shimano's components which were not perfectly-grouped for the longest time ... in the past, THAT seems to have been more of a marketing "thing" than an actual design matter.

So, presuming the SAME 10-speed indexing, I would GUESS that the so-called incompatibility with the new 7900 series rear derailleur (and, shifters) & 7800 components is that the 7900 rear derailleur is possibly/(probably) RAPID RISE ... AND, employing my XTR Rapid Rise rear derailleur with my 6500 STI shifters was something I briefly contemplated mating together many, MANY moons ago to facilitate downshifting.

Is the inner "paddle" on the current STI levers too small to use for downshifting in the rear? Is it too small on a Campagnolo ERGO or on a SRAM lever?!?

BTW. If I'm right (OBVIOUSLY, I could be wrong!) about WHY the 7900 components are incompatible with the 7800, then I suspect that the "adventurous" can incrementally upgrade their drivetrain with just the new rear derailleur IF they deem the current downshifting peformance to be less than desirable DESPITE what Shimano would like people to think.

Time will tell, soon enough! Obviously, I can't wait to actually see the new shifters & rear derailleur BECAUSE some aspects of the new group ARE exactly what I anticipated (some aren't, yet) ... and, since past is (has been!) prologue, I would actually have been surprised if Shimano had failed to introduce the new DA group this racing season.