banerjek

Just installed some 6700 levers on my bike today. The right lever works flawlessly, but the left one takes more force than I'd expect to shift into the big ring. The cable does not seem to be binding -- shifts to the small ring are effortless. The RD itself does not appear to be sticking though it takes some force to move it. Cables and housings are all new and let cable slide freely off the bike.

Trim seems to be occurring when I actuate the A lever rather than the B -- i.e. I can half or full shift to a larger ring with one stroke, but hitting the B lever makes it drop to the small ring right away. Is this installation error or expected behavior?

sqroot3

my left 6700 lever works the way you describe.
did you mean FD, not RD?

kbro1986

He is talking about the FD from what I understand. No problem from going big ring to small. Takes a lot of effort to go from small ring to big. My first guess would be cable tension.

banerjek

Correct. From what I can tell, cable tension is set properly as it does not work as well if it's loosened or tightened.

kbro1986

Yeah, unfortunately I ride SRAM, so i'm not as familiar with Shimano. Used to ride 105 and from what I remember it did take considerable force on the lever to shift to the big ring.

Mike F

I adjusted the FD on my back-up bikes 105 and same thing. Would be very interested in possible solutions

david58

Don't know what is different, but my FD shifting to the big ring on both my bikes (105's) takes more effort than shifting up or down on the cassette. Maybe just the mechanics and leverage disadvantage of shifting in the front compared to the back? I have nothing to compare it to, 105 is all I know (though the Tiagra on the rentabike I rode today seemed to shift pretty easy on the front, in a triple).

DropDeadFred

My DA fd is the same if I'm not mistaken, but I never shift out of the big ring o_O

Pendergast

Sounds to me like your cable tension is a bit too much. Sometimes that can be tricky to get just right.

on the path

Seems you would have to expect a different feel from the respective shifters. The FD and RD perform similar tasks, but are very different mechanisms.

banerjek

That was my first reaction, but the cable is pretty loose in the lower ring. Pulling the cable by hand to make the shift requires about as much force as expected.

Sure, but I've run Tiagra, 5600, and 6600 for years, and it seems like less effort was necessary with those systems. Having said that, my primary bike has Rival on it so I may have lost my feel for 6600 as I've been riding it in conditions that don't call for the small ring and the lever travel to shift to the big ring on Rival is huge.

Pendergast

Too much tension can cause the big ring trim not to work. That's mainly what I was going by.

JustinHorne

It's funny you mention this.


I ride current gen Force, and it shifts flawlessly. That said, I've always seen videos of riders shifting Sram, especially the big ring, and thought that it looked like it was easier for them than it is for me. I chalked it up to my small hands, etc.

One of my friends just bought a Raleigh that's got old-gen Red on it, and I was AMAZED at how much more easily it shifted. I don't mean speed, etc, I mean actual lever throw. I know my cables haven't 'degraded' since being new, as it was always stiff. I think I might upgrade cables sometime this summer.

Bob Dopolina 

Did you wrap the bars before or after you finished adjusting the der?

Sometimes, if you wrap first, the housings are not fully seated in the ferrels and are held that way by the tape creating more drag.

Also, are you sure about the cuts to the housing? Are they clean? Did you grind or file them after cutting them to make sure the cut was clean and square (not at some funky angle)?

Is it possible there is a strand of inner cable that has frayed inside the housing and causing drag?

Also, is the housing inside or outside the bars? I had the same problem with some older K-Wings but I understand that has since been resolved. The issue was the bends in the cable were just too much and it was causing friction.

Just a few possible causes.

Nachoman

I used to run 7800. The difference in effort from large to small, compared with small to large was always pretty big, especially under load. But that didn't bother me at all. It still functioned perfectly. Plus we are only talking about the effort it takes of one finger pushing a tiny lever.

ahsposo 

This is what I'd suspect.

I'll even stick a scratch awl in the opening to be sure.

kbro1986

Stop. Just Stop acting like you know how to wrench...

ahsposo 

Loser.

kbro1986

Actually, I was the first to post in the post-3,000,000 post era. BOOM.

ahsposo 

Pics?

banerjek

Before. This sounds like a real possibility.

They're very clean. I use a metal cutoff wheel. The heat messes up the teflon at the end of the housing, but I make sure everything is smooth and lets cable through well before installing.

Unlikely. I'm very careful to watch for this specific possibility

Inside. I tried to be careful about the bends, but in all honesty, I didn't test.

If this were your bike, would you pull off the tape and redo the job? I hate to do that if it can be avoided, but if that's really what needs to be done, I need to bite the bullet.
Just a few possible causes.[/QUOTE]

Bob Dopolina 

Yes.

I've damaged levers while trying to fight the chain onto the big ring under load. Also, it's just annoying.

akansaskid

Your 6600 had external housing; your 6700 are wrapped and the left shifter wire has an unusual path. I recently went from 5600 to 5700 which also went from external to wrapped. Like you, my left shifter was almost impossible to shift. I was afraid I'd break something first. A few thousand miles later, and it's loosened up and feels like my old 5600. Still way too stiff for my liking, but now no worse than the old external set. Having said all that, it would sure be nice if Shimano could make their front STI shifters work with as little effort as it takes to shift the same derailleur with their thumb shifters.

Ricanfred

5700 shifters and derailleurs. I can trim both with the A and B levers with no issues. Like you I find it takes considerable force to shift to the big ring. Bike has around 400 miles so I'm hoping it gets better, but it does shift nicely. When I compared it to me my previous bike, Sora shifters with 5600 derailleurs with a triple, it took considerably less effort to shift up with that set-up. Hope you get it sorted out....

banerjek

Mystery solved. Problem turned out to be that the FD spring and pivots were corroded up from sweat and gunk which made it resist movement too much in either direction.

It's bad enough I probably should replace it, but I got a very significant improvement simply by cleaning things up the best I could. Now shifting pressure is much less and I get trim in both directions though it doesn't work as well on the B lever because the slight drop in tension doesn't cause the FD to move as much as it should even with tension adjusted optimally. But it does perform the way I need it ot.