Dura-ace 10-7800 vs 7801??

Can anyone tell me the difference between these two gruppos. I just bought a new bike that I believe is equipped w 7800 (according to spec sheet although how would I know?).

I found some good closeout pricing on replacement chains and casettes, but the casettes say 7800 and the chains say 7801. Will performance be better if they are exactly matched? Do I have to worry if my shifters are 7800?

I also heard that Ultegra 10 chains and casettes are more durable, i.e. will last longer w similar performance and therefore were a better 'value'. Is this true, or just hype from someone trying to sell them to me?

Lastly I assume I can also purchase 7900, but since it costs more I assume there isn't much benefit (i.e. some are a tad lighter, but again I assume they are optimized to work in a 7900 drive train, and I know the new 11-28 casette is not back compatable with the 7800 RD).

7800 shifter is for the the rear
7801 shifter is for a double.
7803 shifter is for a triple.

I get great life from the Dura-Ace chains, but use the KMC SL10 normally (it's about 100g lighter)

7900 is nice with the internal cable routing (like Campy, Sram), but a lot more expensive then 7800 right now. Sort of depends on what you want.

A 7900 cassette will cost you $300 MSRP. Ridiculous.

I run Ultegra or 105 cassettes and KMC chains (had the old X-10, which I think is the same as DX-10 now, but now I run X-10SL). I wouldn't run a SRAM chain unless you are running SRAM cassette. If you've been running Shimano chains, don't switch now.

I got over 6k miles on my lst 105 cassette and KMC chain. I replaced them together. I had just started having slight shifting problems in a couple gears.

IMO, DA for these parts isn't worth the money. For shifters, cranks, and cables, yes. Chains and cassettes? No.

Ok. First of all, 7801 is just an update to their 7800 line. Everything is compatible.

The reason 7800 and 7900 cassettes are more expensive is they use titanium for the largest cogs. This has no benefit to us normal people. It weighs about less but supposedly doesn't last as long. I use an Ultegra cassette and a Dura Ace chain. The DA chain is just like $3 more. SRAM chains supposedly never shift quite as nicely...or so I've heard.

IMHO, 7900 is overkill for people w/ day jobs like me :) Shimano is just trying to keep from loosing market share from SRAM Red. AKA carbon bits, internal routing, 11-28 cassette option, weight savings. Some folks even frown on 7900 because it only allows you to drop 2 gears at a time, as opposed to 7800's 3. Or so I've heard. I llllove my 7800. Smooth as butter baby.

DH is 175-180 lb, a bit of a masher, does a little racing and gets about 6k out of DA chains. He actually doesn't replace the cassette everytime either, says it still shifts just fine on the original (although next time it is getting a new one). That is the only experience in our house with them but enough for me to say I guess that aren't as fragile as said. He does keep it regularly lubed and since we are in Texas it is mostly dry weather riding. I would think that does factor into wear.

I run an Ultegra chain but I really don't know my head from my butt on this stuff so whether it is better I wouldn't know. :p

As long as your rear hub is a 7850 and not a 7800, which only takes Dura-Ace cassettes, then the Ultegra cassette is a good way to go. Just remove the cassette to find out-if the freehub body is TI (light grey as opposed to the Aluminum used on the 7800) you have a 7850. And as long as the chain is 10 speed it will work but some shift smoother. (Just avoid SRAM chains.) Ultrega, Dura-Ace, or Wipperman for me- and I prefer the Wipperman.

I use Dura Ace (7700) with Ultregra 10 speed shifters and cassette and 10 spd chain; it's been on several bikes and it's been bullet proof.