Shimano Bar end shifter disassembly & repair

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brucelee
Posts: 290
Joined: 19 Feb 2009, 10:39am

Shimano Bar end shifter disassembly & repair

Post by brucelee »

Hi, I have a couple of broken right/rear bar end shifters (7700-9sp), which I want to have a crack at reconditioning. Anybody know how to get them apart ? Where can I get a replacement drilled indexing washer ?
Cheers,
Bruce.
bar end dissassembly.jpg
Brucey
Posts: 44521
Joined: 4 Jan 2012, 6:25pm

Re: Shimano Bar end shifter disassembly & repair

Post by Brucey »

brucelee wrote:Hi, I have a couple of broken right/rear bar end shifters (7700-9sp), which I want to have a crack at reconditioning. Anybody know how to get them apart ? Where can I get a replacement drilled indexing washer ?


I have not dismantled that model of shifter but normally there is a central splined covering washer (and/or sometimes a crush washer) and then underneath that there is a circlip or (more usually on shimano shifters) a LH threaded serrated locknut. One the clip/locknut is removed all hell breaks loose and it is quite possible that several tiny parts will make a bid for freedom at this point.

You (of course) cannot buy the internal parts for the lever indexing, which is why most folk don't bother to try what you propose to do. Very often the indexing fault in these bar end shifters is actually because of an external plastic part anyway IIRC; I think others know about this in more detail than I do.

If you get anywhere with these levers I'm sure that folk will be interested in what you find so any pics etc would be welcome.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
brucelee
Posts: 290
Joined: 19 Feb 2009, 10:39am

Re: Shimano Bar end shifter disassembly & repair

Post by brucelee »

The plot thickens, Having removed the crushed washer I am now confronted by this :
xxx.jpg
I'm not sure if it's on a thread (there is none evident), looks like a special or improvised tool is required. Anyone recognise it ?
I'm beginning to dwell on the difference between belligerence and determination....
Cheers,
Bruce.
Brucey
Posts: 44521
Joined: 4 Jan 2012, 6:25pm

Re: Shimano Bar end shifter disassembly & repair

Post by Brucey »

the part with the four slots in looks like a (left threaded) nut to me. You can make a good tool for unscrewing it by filing a length of steel tube to leave four prongs sticking out. You might get lucky and have it unscrew with a small pair of snipe-nosed pliers, but don't hold your breath.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
brucelee
Posts: 290
Joined: 19 Feb 2009, 10:39am

Re: Shimano Bar end shifter disassembly & repair

Post by brucelee »

Success, it was a reverse thread, fairly easy to remove with a pair of short pin nosed pliers. Components removed in order shown right to left. The broken drilled washer (the bit a guess needs replacing) actually broke through the plastic shroud and was removed before dissassemly. I then split the rest of the shroud to examine the rest of the assembly. I think this could form the bassis of some sort of repair and maybe a modification to allow 7/8/9/10/11 speed cassettes. But I'm guessing the drilled washer is made from hardened steel. I expected a non-linear spacing between the gear indentations but there seem to be two groups of three.... There were also a couple of small pieces of metal that may have broken off something though I can't determine what (one show to the left of the plastic shroud).

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boblo
Posts: 799
Joined: 24 Sep 2009, 7:35pm

Re: Shimano Bar end shifter disassembly & repair

Post by boblo »

That's how they seem to fail. The index ring breaks and makes a bid for freedom through the plastic shroud. I'm sure it's hardened and almost certainly not available as a spare. I've had a few levers go like this and end up replacing them.
Last edited by boblo on 26 Oct 2014, 4:14pm, edited 1 time in total.
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gaz
Posts: 14649
Joined: 9 Mar 2007, 12:09pm
Location: Kent

Re: Shimano Bar end shifter disassembly & repair

Post by gaz »

Intrigued to know how those internal parts compare with a standard down tube shifter, not that I am ever going to attempt disassembly of either myself.
High on a cocktail of flossy teacakes and marmalade
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