mlamb01

I'm having an issue where it is slow to shift up and down in the back. It will sit there and grind for a few seconds before shifting... If I am to a bigger gear, I can lightly tap the level and force it to go. Going down to a smaller gear I just have to wait. Does not happen all the time, maybe 20 to 25% of my shifts. Started noticing this about 100 miles ago and it has gotten progressively worse.

Bike has almost 5000 miles. Chain and cassette are Shimano 5700, with 212 miles on them. Other parts of the drivetrain are Shimano 5600, including brifters. I replaced the shift cables earlier, they have 659 miles on them. The rear cable did almost break, it only had 3 strands holding it together when I replaced it.

I have cleaned the inner wire and dripped lube into the housings, it still did not seem to help. I have oiled all the pivot points on the rear derailleur, and it did not seem to help. I have not tried lubricating anything inside the brifter yet...

Elvo

Adjust cable tension.

mlamb01

Which way do I adjust it? If I tighten it, shifting to the bigger cogs gets better, but shifting to the smaller cogs get worse. The opposite is true if I loosen the tension. Right now it seems to be adjusted perfectly in the middle, its like there's not enough movement in either direction to shift successfully 100% of the time.

billykmd

You mentioned you replaced the cables. Did you make sure there were no bends in the cable since that make a difference... Since the previous cable was almost shredded, may consider the housing and make sure there are no kinks in the housing. If the cable tension adjustment is in the middle, the other thing could be derailuer itselft?? I'm no mechanic by the way...

mlamb01

Hmmm... No kinks in the housing or the wire. I slid the end out of the shifter, and it was not frayed. I did check out the housing ends, and I did find a slight bend on the end that makes the sharp turn and goes into the rear derailleur barrel adjuster. Its made out of plastic, and looks like it has taken a slight set. Rotated it 180 degrees(to bend the kink out), and slid it back onto the end of the shifter cable housing. It might have made a slight difference.

Bioluminescence

This is a nice video explaining how to adjust the rear derailleur.

mlamb01

Thanks for the video... But I've already been there and done that.

tagaproject6

Check the clearance between the largest cog in the rear and the upper jockey pulley. Too much gap in this section will cause shifting delays. The gap should be just enough space between the teeth on the biggest cog, the chain, and the upper jockey wheel. Adjust the "B" screw to set the clearance. Ensure that the alignment is also straight along the cassette and the pulleys. An angle here will also cause shifting problems. Check your hanger if it is straight.

BarracksSi

Also see if the derailleur hanger needs to be straightened. If I can't get a bike to shift cleanly by the adjustments mentioned so far, it's always because of a slightly bent hanger.

Sundance89

If I'm reading this right, when you replaced your cables you 'did not' replace your housing as well? I would lean towards that then. The fact that you have to "wait" and have hesitation leads me to think too much friction coming from the housing somewhere. To be safe, or at least to rule it out, I would get new cable housing.

BarracksSi

Hmm... I'm not sure I would buy into that idea. I could imagine a cable hesitating if it was stretchy enough to get hung up in a section of housing, but steel cable just isn't that stretchy, especially the short length that fits on a bike.

For now, I'm sticking with my thought that the derailleur hanger could be a bit bent.

Sundance89

No, I meant (and thought you meant) the other way. The shifting was hesitating on the release, when shifting into the smaller cogs. No? Just out of curiosity, how many miles (or how old) is your housing?

flip

When you replaced the cables, did you use electrical tape to secure down the housings to the handlebar, underneath the bar tape? it's easy to constrict cable movement if you taped too tightly.

mlamb01

There is about 5000 miles on the housing. The shifting hesitates when shifting into both smaller and larger cogs. Its kinda baffling, because I figured if it was sticking in the housing shifting to a bigger cog would be fine, and shifting to a smaller cog would be bad... But shifting is bad for both.

mlamb01

I have the 5600 series of the 105 shifters, the routing is not underneath the handlebar tape.

BarracksSi

I'll clarify what my bikes' symptoms were when it was just a bent hanger --

Say that I set the cable tension just right, starting from the smallest cog. It would then shift fine maybe three or four cogs bigger, then it wouldn't work right -- it would hang up and shift halfway without falling into place, or maybe start skipping, or whatever. Going back to the smaller end, it would settle down once it got to the smallest cogs.

From there, if I tried to reset the tension so that the big end of the cassette shifted well, the small end shifted like crap. I'd still only have half of the cassette working well.

Everything else was adjusted right -- B-screw, limit screws, new cables & housing, everything. I was stumped. The RD looked straight, but something made me check to be sure. Straightening the hanger -- did it the first time at home with a spare wheel, took another bike to a shop where they had the proper tool -- I could get the whole cassette to work again.