barrychen0507

As the title suggested, my 105 5800 Right shifter will not release tension so that I can shift into the last cog (the smallest cog). I pulled the cable with my pliers (with decent amount of force for sure), and it just will not move a millimetre in the last shift. I can hear the click noise from the shifter tho (erm, maybe I'll post a yt link later on). What can I do? It's definitely not the RD's problem, do I have to replace the shifter or is there some potential problem that I can probably solve without replacing it?

Edit:
/shorts/gP8S7qGACPE?

delbiker1 

I am not sure what you mean by "I pulled the cable". Do you mean while tightening the cable anchor bolt at the rear derailleur? If so, you likely have put too much tension on the cable before tightening the cable anchor bolt. You should not have to pull it that hard. The derailleur needs to be on that small cog when you tension and tighten the anchor bolt. Have you tried the adjustment barrel on the rear derailleur? That may need to be turned clockwise. Have you tried adjusting the derailleur limit screws? If the cable tension is right, the limit adjustment should allow the cage to move enough to get to the small cog. The outer limit screw should be turned counter-clockwise to to give it the ability to jump onto that cog. You may have to adjust the inner limit also to get to where all 11 cogs can be reached. Most of the time, this issue has to do with the cable/derailleur adjustments. If your shifter can click 10 times, it is likely ok.

Try Parktool.com for a video on this subject.

barrychen0507

Erm, the problem is the 10 clicks.

And by the mean of 'I pulled the cable', I meant that I unscrewed the RD, and simulated the tension when pulling the cable with a plier. And the last one just won't move a millimetre like other gears do.

It only has 9 clicks for the one that shifts into the harder gear, but has ten (but 1 does not shift at all) when shifting into the easier one.

The limit screws was set up properly, and it shifted correctly for 10 gears, but misses the last or first cog (both the largest one and the smallest one, when fiddling with the barrel adjuster of course, it depends. For example, it either shift from 1-10 or 2-11, so I don't think it's the limit screw's problem.)
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I did posted a video on youtube, but the site told me I have to have 10 posts in order to put a url, so I just edited with a link but without youtube com, maybe you can have a look, thanks.

andrewclaus

Is the cable disconnected from the derailleur? If not, do so first. Then shift into high, squeeze the brake lever (you may also need to loosen the brake cable) and push the cable end out of the access hole. Inspect for fraying, replace if needed. Then spray a liberal amount of solvent like WD-40 into the hole to clean out the works.

Then individually inspect each piece of cable housing and its ferrules. Clean, lubricate or replace as needed.

Then be sure the derailleur operates correctly by hand and the limits are adjusted right.

barrychen0507

Sure, I'll try to inspect the cable status and try to see if it will help.

delbiker1 

I am not being critical, but I don't quite understand your explanation. If you have 10 clicks with one, you should have 10 clicks with the other. How do you know the limit screws are set correctly. Have you tried adjusting them to at least eliminate that. It does not take much error to have the limits set wrong. You can just eyeball the line up with the derailleur and the small and big cog, then adjust if needed. Tried to see the video, but no luck finding it on youtube.

barrychen0507

It does go up to the largest cog and the smallest cog (when I fiddled with the barrel adjuster), the limit screw wasnt the problem, it just only shifts ten gears.
It turned out that the cable was actually broken into many small iron lines in the shifter as the cable hadn't been changed for years, and was faulting the shifting mechanism (as I would think). But still, idk if it will solve the problem after replacing it (which I'll buy tomorrow and install it), and we'll see after I install that cable.

Andrew R Stewart 

A fraying apart cable can certainly jam up the shifter spool's movement as well as hinder the cable's movement through the pathway from the spool to the housing. Many shops (and Shimano) suggest replacing the rear shift cable every year as a precaution form the broken off end becoming trapped in the shifter (and the entire lever being replaced, you do the math). Andy

barrychen0507

I'll change out the cable each year in the future, since I do know the cost of buying a whole new set of the shifter. It's very pricy indeed.

Although I still don't know if that will solve the problem tho, hopefully it will, let's see.

Iride01 

Before you do much of anything else, disconnect the cable from the pinch bolt on the DR. pull the hood up on the shifter and push on the bare cable running up the down tube so about 4 - 6 inches of cable are exposed from the shifter. Look for a frayed strand or strands of cable. If you've waited too long the frayed strands might make it very hard to get the cable end exposed from the shifter.

https://si.shimano.com/api/publish/s...002-05-ENG.pdf

https://si.shimano.com/api/publish/s...003-09-ENG.pdf

https://si.shimano.com/#/en/search/S...5800&type=ROAD

Another possible problem might be that someone mucked with the high limit screw and it won't let you feel the 10th detent because the cable has too much slack in it because the DR can't move to the 11 tooth cog. But don't touch that until you eliminate everything else. Limit screws are seldom wrong once they are correctly set at installation.

Never mind, I should have read your prior post before Andrew R Stewart 's reply.

Your first post described the classic case of a frayed cable and I was in too big a hurry to respond.

delbiker1 

The fraying cable will always screw up the shifter eventually. The new cable will almost certainly solve the problem if all the rest is correct. I would suggest replacing all cable and housing if they are all that old. I apologize for missing the obvious cable issue. I was assuming, and I should know better, that you were installing a new cable.

andrewclaus

And pay attention to cable adjustment issues. I'll guess you've had to fiddle with the barrel adjusters a couple of times in the past few weeks or months. That's a watch-out situation.

I hear some Shimano shifter models are worse than others, but the models I've had over the decades will eat a cable in a few years with about 6000 miles/year of mountain and foothills riding, so a fair amount of shifting. I inspect every year and have never caught it that way. After two breaks on the road, I'm now really good about checking the cable every time I need to change the barrel adjuster.

Andrew R Stewart 

I fall into the assuming pit too often myself. It's so easy for me to go past the most basic first steps of a problem repair, the steps that most any experienced wrench knows blindfolded. I am often reminding myself that most here don't have the depth of understanding and experience that a few do and, thus, often don't supply needed data or miss reporting small but important details. Andy

barrychen0507

Sorry for the late response, the site told me that I was going to have only 5 posts per day.
Anyways, after I changed out the cable, all things sort. Although, I left a piece of the plastic guiding tube inside my frame as it was too old and it just broke inside xD

barrychen0507

I've learnt that as well. I will surely change my cable yearly and inspect my braking cable as well.
It had shifting problem prior to this incident, I thought it was just because the derailleur hanger wasn't straight and wasn't bothered to solve it, and now I know that the cable will indeed affect shifting performance and might get stuck inside the shifter.