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Cable, part II
 

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April
Joined: 13 Dec 2003
Posts: 6593
Location: Westchester/NYC

8/8/15 7:42 PM

Cable, part II

I thought my STI derailleur cable was broken at the clamp bolt. That turned out not be the cause of my problem. The cable was seriously frayed but still got a few strands connected.

When I went to replace the cable, I found the shifter end was gone!

The hole where the shifter cable was supposed to go through, was open and free. The old head was nowhere to be seen.

I easily fit the new cable through. But although the shifter "clicks" normally, it's not pulling the cable! (I've shifted the shifter into the "relax" position for the installation)

What gives?

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Brian Nystrom
Joined: 26 Jan 2004
Posts: 5101
Location: Nashua, NH

8/8/15 8:47 PM

I've seen that once

I encountered a guy with that problem once on a local bike path. Every once in a while, the shifter would catch and move the cable, but for the most part, it did nothing. Unfortunately, I have no idea what the solution was. I suspect that it was a either a broken spring or a seriously gunked-up shifter. You could try flushing it with solvent or WD-40 to see if it's just full of crud. If it turns out that it's something broken, good luck finding Shimano parts. They treat their stuff as if it's disposable, which is a major reason why I will never use it.

Last edited by Brian Nystrom on 8/9/15 4:46 AM; edited 1 time in total

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Sparky
Joined: 08 Dec 2003
Posts: 19083
Location: PDX

8/8/15 9:04 PM

If the WD-40 flush works, just remember to actually spray lube within a few days. The WD-40 will flash off leaving a dry mechanism. It is NOT a lube. Else you may have a shifter that work great for a week and is then shot.

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April
Joined: 13 Dec 2003
Posts: 6593
Location: Westchester/NYC

8/9/15 6:13 AM

Odd thing is, it was working reasonble well up until the old cable broke. Now it won't catch the new cable at all.

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Dave B
Joined: 10 Jan 2004
Posts: 4511
Location: Pittsburgh, PA

8/9/15 7:48 AM

Perhaps the old cable head isn't really "gone" but is resident in the shift mechanism and that's what's causing the current problem.

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Jesus Saves
Joined: 16 Jun 2005
Posts: 1150
Location: South of Heaven

8/9/15 8:21 AM

Good point, Dave B. I worked on a bike that had that problem.

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April
Joined: 13 Dec 2003
Posts: 6593
Location: Westchester/NYC

8/9/15 12:24 PM

Spot on (I think). I spied some strayed wires in the shifter mechanism. Have to take the shifter apart to see if I can dislodge them.

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Sparky
Joined: 08 Dec 2003
Posts: 19083
Location: PDX

8/9/15 1:02 PM

Don't take a Shimano STI 'too' apart, as there is a point of no return literally.

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Jesus Saves
Joined: 16 Jun 2005
Posts: 1150
Location: South of Heaven

8/9/15 3:58 PM

Agreed. I would try using a can of compressed air while moving the shifter/lever to try to dislodge whatever may be jammed up inside.

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April
Joined: 13 Dec 2003
Posts: 6593
Location: Westchester/NYC

8/9/15 5:41 PM

I have taken one (partially) apart. So I know one "point" that's safe to return from.

The only problem (at the moment) is I couldn't use that bike today, nor next Saturday, which forces me to change my riding plans. (I had in mind of doing some dirt roads today and next Saturday, had to stick to the paved surfaces)

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greglepore
Joined: 10 Jan 2004
Posts: 1724
Location: SE Pa, USA

8/10/15 6:53 AM

Yeah, this is why you don't want the head to break off. If you've had one apart, you're ahead of many shops. The flush trick works with accumulated gunk, not so well with cable strands. Have at it and good luck.

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dddd
Joined: 11 Jan 2004
Posts: 3345
Location: NorCal

8/12/15 12:59 PM

On certain of Shimano's STI levers the rear-most cover of the shifter assembly is just a disk of black plastic sheet, anchored about it's center where the brake lever pivot bracket attaches with the castle nut. I've pried the edge up to remove a broken cable head, and the plastic rebounded to it's original shape and sealing function when released.

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Brian Kelly
Joined: 12 Jan 2004
Posts: 653
Location: Gig Harbor, WA

8/12/15 1:22 PM

An older shifter, but much of the dissassembly may be similar

https://youtu.be/xkGNN_2CfCY?list=PLxO5aF0sensjhmcBDEWCrCHTSmIwBkMFt

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April
Joined: 13 Dec 2003
Posts: 6593
Location: Westchester/NYC

8/12/15 5:51 PM

Thanks for all the tips. I'll be tackling it Friday-Monday when I'm back in Westchester (minus Saturday, when I'll be busy riding...probably a full day affair)

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April
Joined: 13 Dec 2003
Posts: 6593
Location: Westchester/NYC

8/14/15 3:37 PM

Success!

Dave B was spot on!

I thought I spied a shadow of some strayed cable. Tried pulling it out but to no avail.

Before I was going to take the shifter apart, I thought I should remove the new cable first. In the process of pulling the new cable back out of the shifter, the old cable "reared its ugly head", quite literally!!!

Some poking, pushing (with old cable) and pulling finally got the old cable and head to come out just enough that I could grip it with a plier and.....out it came!

Yeah, the black art of Shimano component repair! ;-)

(This is the 2nd time I save this particular shifter from the trash can)

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Sparky
Joined: 08 Dec 2003
Posts: 19083
Location: PDX

8/14/15 6:56 PM

Happily and luckily it did not do damage in there when you actuated the shifter with the new cable..

Glad you got it, loosing an STI or Ergo shifter sucks to be sure...

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April
Joined: 13 Dec 2003
Posts: 6593
Location: Westchester/NYC

8/14/15 8:09 PM

Never had any problem with my Ergo shifters. It's going strong at almost 20 years! (1996)! OK, going strong is a bit exaggeration. It was up to about 2-3 years ago. Now I need to do something to revive the "spirit" of the rear shifter. It's been sluggish...

But I'm not being entirely fair. I crashed the Shimano...

The Ergo, by luck or whatever, came through my 2 recent crashes unscathed.

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KerryIrons
Joined: 12 Jan 2004
Posts: 3236
Location: Midland, MI

8/17/15 3:33 PM

Revival


quote:
Now I need to do something to revive the "spirit" of the rear shifter. It's been sluggish...


First thing to do is to flush it with WD-40 or TriFlow. That works most of the time. Otherwise it could be G-springs.

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April
Joined: 13 Dec 2003
Posts: 6593
Location: Westchester/NYC

8/17/15 6:59 PM

Already done the flush routine. I'm afraid it's probably g-spring thing.

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greglepore
Joined: 10 Jan 2004
Posts: 1724
Location: SE Pa, USA

8/17/15 7:17 PM

if you can pull apart an s brand lever, campy is a piece o cake.

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April
Joined: 13 Dec 2003
Posts: 6593
Location: Westchester/NYC

8/17/15 7:32 PM

I didn't completely disassemble an S-shifter, only enough to fix the problem I had (crash damage, last year).

I've been warned it's something that should be taken with a lot of care. Not sure I want to do it in the middle of the season and risk having the bike out of action.

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dddd
Joined: 11 Jan 2004
Posts: 3345
Location: NorCal

8/18/15 9:58 AM

I found several videos online which go through the rebuild of Ergolevers.

I looked at a couple of them to catch all of the possible detail issues, and then found the process to be quick and easy.
I took a few notes as to spring tensioning and parts position detail as I removed each of the small number of parts, which turned out to be overkill.

The springs themselves are widely available and inexpensive.

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