Which Groupset?

What is the extra rivet point for?

They added a second rivet point between the largest cogs and the carbon fibre center cluster.. If you look at the back of the latest cassettes and you'll see two rivets were there was one and also a different profile to the cogs to allow the extra rivet to be installed. I would guess it was done to strengthen the larger cogs connection to the carrier and prevents it from getting loose. Because although you appear to have been lucky, there are numerous threads on the web documenting these cassettes falling apart.

5800 weights: https://www.flickr.com/photos/13647127@N04/sets/72157645790442968/

Both.
(and quotes)

I'm not sure I even have a carbon carrier - looked like Ti and Alu to me. You sure you're talking about DA? Bearing in mind I was in a mad rush last time I swapped cassettes so I may not have seen any carbon bits.

^ yes it's carbon on Dura Ace .. Take a look at this pic it clearly shows new (on the right) and pre modification (on the left)

http://brimages.bikeboardmedia.netdna-cdn.com/wp-content/uploads/2014/06/shimano-dura-ace-da9000-cassette-running-change04.jpg

^ yes it's carbon on Dura Ace .. Take a look at this pic it clearly
shows new (on the right) and pre modification (on the left)

brimages.bikeboardmedia.netdna-cdn.com/wp-content/uploads/2014/06/shimano-dura-ace-da9000-cassette-running-change04.jpg

Ta. I'll have a look at the new one I got tonight.

5800 105 dropped at Merlin.

Looks like a great groupset for the money

£325! Damn.

It looks awesome. Shame there's no 'cross suitable crankset. Yet.

Even cheaper with quidco - I've just ordered it for a new build

weren't they releasing a 105 disc groupset too or I imagined that?

Can't you get rival 22 in all sorts of combinations including hydraulics etc. also what constitutes a cross suitable crankset?

They will soon, more like the brake/shift set.

@8bits

weren't they releasing a 105 disc groupset too or I imagined that?

They are doing a non-series hydraulic mechanical STI shifter, the RS685. Expected release some time later this month, although I'll believe it when I see it.

weights, then:
5800 - 2,474g (using 6800 chain weight)
6800 - 2,274g
7900 - 2,087g

are they manufacturers make believe weights? This is the weights I have from a post where Fairwheel bikes weighed individual components from current (at the time) group sets

Shimano Dura Ace 7900 = 2277g

Shifters, 365.7
Brakes, 294.8
Crank, 744.9
frt der, 63.9
rr der, 164.2
chain, 251.1
cassette, 160.7
cables/housing, 231.7

If you don't include cables then it's 2045g .. and there'll be some variation due to manufacturing tolerances

I puckered up and bought it.
Good excuse to completely rid my life of all traces of campagnolo.

Anybody wanna buy the 11-28t cassette off me though?

Also means i'll be selling chorus F&R mechs, athena shifters, and some un-used centaur carbon cranks, and a set of Kyserium SL wheels with record cassette....

The Campag cassettes will work with 11 speed Shimano - I rode in this morning with a Chorus 12-27. However if you want rid I'd happily take the 11-28 off you, as I need 1 more tooths top end for Oval-Kennington.

I know this has been endlessly debated but...

I'm looking into purchasing a full groupset. I'd be happy with an older 10 speed SRAM Force (GXP) as I was happy with my old Rival groupset on the BMC. Hard to find though and not anywhere near as good value as a new 105 groupset.

So, plump for full 11 speed SRAM Force 22?
or Shimano 105 full set?
Or buy individual bits and mix and match - Force cranks, Rival mechs, Rival brakes and brifters? Too many options.

Could be going on an older cannondale Caad8.

new? then ultegra 6800. £499 from Merlin
http://www.merlincycles.com/shimano-ultegra-6800-groupset-oem-69564.html?utm_campaign=googlebase-GB&utm_source=googlebase&utm_medium=shopping&utm_term=Groupsets+by+Shimano%2C+Campagnolo+and+SRAM&gclid=CN6bkrO4g8ACFUjlwgodxHoADQ

@dammit
email me.

If you find the hood shape of the new Ultegra comfortable and like the shifting, go for the 105.

Make sure your wheel is compatible.

Woah, that ultegra price is quite cheap. For that I could deal with the less than optimal rear cassette. Would miss double tap though.

That seems like a good choice, unless I find a super cheap slightly used Force option.