jamesdak 

Missing the faceplate on the one ST-6600 10 speed shifter on my CAAD8. Had gotten a nice set of ST-7800 shifters with the bike so those were swapped on. The ST-7800 don't seem to have enough cable pull for the Shimano 105 FD that the ST-6600's were working just fine with. Thought they'd be a direct swap since both are 10 speed. I thought the cable pull change came with Dura Ace 7900?

What do ya think, should it work?

Can't find a Shimano compatibility chart that has the ST-7800's on it.

dedhed

https://www.celebrazio.net/bicycling...no_jp_2008.pdf

Crankycrank

Are you sure you have the cable routing on the 105 derailleur clamp correct? Not sure if yours is the 5600 105 or ?? but here are the cable routing instructions. SI-5JM0C-001-ENG.pdf (shimano.com)

jamesdak 

Yeah, this is what I am wondering too. I actually have the LBS doing this one and haven't picked it back up yet. Normally they do awesome work on my stuff but this one seemed to stump them. I didn't check compatibility because I didnt' think it was a problem. I do have a FD-7800 I can put on this bike but figured the one on there would work if it did with the Ultegra shifter.

Don't remember which FD it is off the top of my head.

dedhed

Doh front.
​​​​​​https://www.celebrazio.net/bicycling...no_jp_2008.pdf

jamesdak 

Just got it back. The FD is really old, it's a FD-1050 so it most likely is the issue.

I thought about this more as I drove to town. I've only had a few rides on this since it's a recent pickup. FD was rubbing on the outer ring and I adjusted for that. Then I found the crank had a lot of side to side play in it. That had allowed grit inside the BB past the seals. So I replaced the BB, put on the crank, but never fully checked everything since I was already planning on doing the other work to it. So this probably never did work correctly as I think about it.

jamesdak 

So, just to close the loop on this. It was the FD. It took me all of about 5 minutes to put on the proper FD-7800 and dial it in. Shifting seems spot on with no rubbing on the stand. As soon as the rains stop this will get a real test ride.

For someone who usually messes with old steel bikes this thing is now crazy light. My lightest steel bike is my one Giordana XL Super at 17 lbs 14 ozs.

This beast now weighs in at 16 lbs 8 ozs as in this picture except for the FD. I grabbed this pic before I put on the FD-7800.

icemilkcoffee 

There is your problem. The FD 1050 is a pre-brifter era FD and has the wrong pull ratio for brifters. You need the 105 FD1056

jimc101

Nice build! well color coordinated

wheelreason

No....

jamesdak 

LOL, it certainly isn't subtle.

But on it's first ride yesterday since all the work was done, it's finally living up to the Cannondale reputation of being fast.