The Shimano Dura Ace 7900 Shifters have been completely redesigned. The brake levers are constructed of carbon and the shift cables are hidden beneath the handlebar tape with no loss of performance. Feel it - test it - shift it.
Strengths: Sturdy design, light weight, stiff, well made.
Weaknesses: Ergonomics not right; touches a nerve.
I have to agree with mnotheis about the lack of ergonomics. I loved these shifters when I first upgraded from 7800 a few months ago. I liked the flat hoods, which SRAM and Campy have. But I've become really sensitive to a pressure point somewhere, and I think it's coming from inside the index finger where it wraps over the hoods and contacts lever. The sensation is like touching a nerve - literally the same feeling as hitting the funny bone. I have them well positioned I believe, with essentially no bend at the wrist. If I can't find a solution, I will be swapping them out, either for SRAM or downgrading back to 7800.
a Road Racer
Date Reviewed: January 19, 2012
Strengths: Ergonomics/comfort, functionality, weight, looks, price. Seamless transition from 7801's. They work exactly the same way. My comfort zone (personal preference).
Weaknesses: Little harder to install the shift cable housing by the brakes cable (though it results on a superbly cleaner look). Tape the brake housing first, then tape the shift housing. After you install the handlebar tape, you will like the results. Jagwire, Gore, Shimano, listen: now that all systems run both housings taped to the handlebar, you should produce an integral double housing for the handlebar portion of them, to make installation a breeze!!
This STI-7900 shifters replaced my STI-7801 ones. VERY comfortable. More so than 7801's when on the hoods (holding onto them the way Pro's do). Having read previous reviews, I made sure I would not struggle with set up and rigging, so I also replaced all cables with Jagwire Racer's complete set as well. I found shifters to have very smooth and precise operation, besides a cleaner look. Set up and rigging posed no issues. Performed flawlessly from the start. And for the record, rear shifter downshifts three cogs when lever actuated three clicks, unlike I read somewhere. 7800 brake calipers, in fact, operate/feel a little better now.
7900 is the new 2004 105! Having ridden my wife's ill-equipped 105 triple bike from 2004 vintage, I can say it is on deck with it in terms of feel, and overall sub-DA performance. I too was wooed away from the 7800 set I have loved for six years to be part of the latest hook. I have shunned SRAM, not even considered Campy, and am now flabbergasted at the poor 7900 setup. Di2 rocks though, so my faith is only tarnished...FOR NOW. And for reference I have two 7800 sets left in my stash that will not ever be sold.
Stupid cost aside - press on dear reader before you step into 5700/6700/7900 too.
Brakes are wonderful, the 7800 was too. So not much to write home about, I can lock up the wheels when needed on both sets, or modulate my way around anything. Work well in wet and dry and much better on carbon clinchers.
I use a BB30 Hollowgram crank and love it. Never had issue with a 7800 crank, so I am sure 7900 works just fine with it's matching chain. Have also used the Easton EC90 crank, no issues there either.
Front derailleur is very nice and is improved from the 7800 for a more rapid engagement. Impressed.
Rear derailleur is a bit flexy it seems, but shifts along at it's lumbered pace. I cannot really blame it for anything but following what the lever indicates it should do along it's parallelogram path.
Ah, the shifting. Remember this is Dura Ace right... And I even waited more than a year post-release so the engineers could quietly fix any population-unknown issues at the initial huzzah into production. Levers are nice, the carbon does not get as cold or hot as alloy. Levers feel a bit slippery but I like their width. Could have used some texturing or similar surface finish update. The nubs that used to be grippng points are gone. I cannot wrap around the tops of the body and TT away. Miss that dearly. I do like the wide-body flat setup and gives hands a nice surface to sit on.
The travel loss is large and the shifting imprecise. By this I mean sometimes (which means too often) it misses an upshift (taller gear) and has me guessing what is next. Downshifting gives you only two per sweep. On my setup if you are on the third cog down and downshift (going for two) all the way it will engage the top cog, then drop to the second. Yet it gives a click, click, indicating two shifts made. Then you have to shift AGAIN to get into first. Numerous attempts to dial this out are unsuccessful. Now having routed my cables to the inside, I may have caused this issue? Why would it be offered then? Unsure. The shifting has a dull, friction induced yawn that only begs to be put down and covered with rocks. If this were given to me in a field-test situation, I would have said the same thing. I think Shimano must have had a group-think biodome of yes-testers that could not bare their soul to how blaise the top-drawer groupset is. My hope is for 2011 or 2012 there is a cheaper Di2, wireless Di2 and a 8000 groupset that takes all that is awesome from the 7800 and few goodies from 7900 and gives us Shimanophiles another reason to not jump brands. Ye have been warned.
Strengths: Like the stiffness; carbon levers; precise snap to the shift. Very positive braking.
Weaknesses: Ergonomics on the hoods. Don't like the shifter cables paths. I always used the cable extensions as a place to hang onto and try to get low in an aero position.
Also, this series requires a special (low friction) cable (by Shimano $$$) that loops on the inside of the H'bar. No telling how often you will have to replace it.
DA 7900 shifters. I have used Shimano products my entire cycling career. I have had DA 8, 9 & now 10 speed.
The 7900's funstion fine, look good, BUT, they hurt the heck out of my hands. I have tested them for some long rides on a test bike and I am going to stick with the 7800's.
The 7800's fit the hadn better. I am a design engineer and have performed a lot of ergonomic studies and conclude that the top of the shifter hood (rounded ball shaped) creates a high pressure point and is very uncomfortable.