bryceman

My race rig currently is setup with 7800 DA and would say it has in the neighborhood of 15k miles on it. Replaced the rear derailleur earlier this year with a 6700 unit off of my CX bike due to cable slip. Have had shifting issues on/off for about a year on this bike and want to move to something better. Would really like to move to internally routed cables and from what I gather the 6700/7900 units are a step backward from my current 7800.

With all of that said, would you just replace the shifters with 6700/7900 since they will be newer and more efficient or would you bite the bullet and go with a full 6800 groupo (only $650 from PBK right now). I have reviewed wheel information and can get a freehub for my powertap and boyd wheels to convert over.

Thoughts?

gsteinb

Thoughts...

15k miles is a decent year. I've got 6 or 7 hard years on a 7800 group.

bryceman

Well, the shifters were used when I bought them, so the total life on them is questionable.

More what I am getting as is that if I wanted to go with a internal routed bar cables, are 6700/7900 really a downgrade that is noticeable or should I go ahead and move to 11. The groupset as-is probably has a $400 value on it and full 6800 is only $650. Replacing the shifters alone wouldnt be a large expense since the current 7800 units have value too.

cafzali

Just curious as to why you immediately went to replacing it as a result of shifter wear? Usually replacing the RD cable, cassette and/or chain will solve that issue.

bryceman

The RD was replaced due to the cable wearing down on the bolt location. The 'grove' under the bolt had worn down so much that the cable was allowed to pull slightly. This must have been due to multiple incorrect installs by previous owner.

The shifters have not been replaced yet.

What I am hearing here is -- keep the shifters, replace downstream components if there is still shifting slop.

Dunbar

7800 to 6800 won't likely improve shift quality. More like a lateral move. But you get the newer, larger hoods which IMO are an improvement over the 7800 generation stuff and of course the new stuff looks better. Braking is probably better with the new calipers.

It's your money but 5800 is an even better value and I doubt you could feel the difference between it and 6800.

And 5700/6700/7900 shifts very good with the new 11sp polymer coated cables installed but I wouldn't bother with it at this point. If you already owned it that would be a different story.

bryceman

Interesting. Didn't really think about going to 5800 since the 6800 groupo was such a 'deal' @ $650 shipped (compared to the retail sticker of $1499). PBK doesnt carry the 5800 groupo, but looks like Ribble has it available for ~$440 -- though the 53/39 cranks are out of stock.

hack

Merlin has the 105 group for $450 and have the 53/39 in stock:

Shimano 105 5800 11 Speed Groupset Black | Merlin Cycles

shovelhd

I don't know why you say that 7900 is a downgrade from 7800. You've been reading too much noise on the net. The crank is stiffer. The shifters don't eat cables. The brakes are more powerful. The front derailleur adjusted correctly needs no trim. You might want to ask guys that have actually raced 7900/7970.

You have to decide whether you want to stay on 10 speed or go to 11. Wide or narrow.

Make sure your Powertap has a 15mm axle or you will have to replace the wheel as well.

soma5

6800 front shifting is better than my 7900 front. Rear, not so much. 9000 trumps both but that's not part of the discussion, apparently. I'd go with 6800 over 7900, myself, if going 11-speed.

Ygduf

man, the one thing about shimano: too many numbers. wtf are all those gruppos.

mattm

One of the many reasons campy wins!

Ygduf

We aren't all paid in iBucks.

Dunbar

Running the derailleur cables under the bar tape adds friction and makes the shifting less slick. The new polymer coated 11sp cables will fix that but I'd go 11sp if I was going to drop money on a new groupset in 2014. If you're already on a well functioning 5700/6700/7900 group 11sp is a lot harder to justify.

aaronmcd

My cables are under my tape and I noticed no difference in shifting. But speaking of shifting, mine is getting bad. I think I need new cables. Do cables or chains usually wear out faster?

Dunbar

The new polymer coated Shimano cables require half the force to downshift the RD. I had them on my 5700 setup. Getting ready to install 5800 on my Roubaix. Chains usually wear faster although most people change cables on a calendar basis not mileage based.

shovelhd

Again, is that your opinion based on your own racing experience or is it net pinion? I have raced 7800 and 7900 hard and 7900 shifted better with equivalent effort. I did not use DA cables. Oh, and I have a perfectly functioning 7970 group that I am in the process of upgrading to 9070.

globecanvas

When you say "in the process", you mean collecting parts. right? That's an all-or-nothing swap, isn't it?

shovelhd

Collecting parts, yes. It is an all or nothing swap at the group level. The 7970 wiring harness uses Di2 connectors while 9070 uses E-Tube like 6770 and 6870. If I had 6770 or 6870 I could keep the back half (behind the B junction) of the harness as it is the same. The front A junction has to be replaced when going from 6770 to 6870 or 9070. I have all the parts on route. I plan on tearing the bike down next week. I can't ride it, so I might as well decapitate it.

Dunbar

At the 105 and Ultegra level yes. I currently own/owned 5500, 5700 and 4600 equipped bikes and rode a 6700 equipped loaner bike for ~500 miles. The externally routed Shimano shifters require much less effort to downshift the RD. I'm not saying 5700/6700/7900 shifts poorly when setup properly with good quality cables/housings but it's not as slick as the older (and newer 11sp) stuff. There were lots of complaints about 7900 being a step backwards in shift quality when it was first released. As it trickled down to Ultegra and 105 you also started to see the same complaints from people upgrading their older Shimano groupsets.

Ygduf

I enjoy that shimano seems to literally need 9999 version numbers.

globecanvas

Yes, it's much more confusing than talking about, say, SRAM red vs SRAM red black... :/

Ygduf

you mean all of the interchangeable versions, or how the latest is like 2 years old and still lighter and doesn't eat cables?

Shimano stuff is fine. Every time I have to rent a bike I get it. But and is some funny stuff!

globecanvas

Mind you, I have SRAM on 3 bikes and Shimano on one. But to be fair, the "wiring harness" quote, and every single one of those model numbers that ends in 70, is all about stuff that doesn't apply to SRAM for obvious reasons. The different numbers refer to 10 vs 11 speed, or ultegra vs DA. It's easier to type "9070" than "11-speed electronic Dura-Ace."

Ygduf

it's not obvious to me, I don't know the numbers -> gruppos at all. It's all just 6070809006080709808060907080