STI shifter stuck.

[peetee]

I’m looking for some suggestions as to how to unstick a RSX 7 speed shifter.
I’ve come across this issue many times with older Shimano and spraying loads of GT85 in the workings does the job every time.
Not this one, oooooh no. It’s from the Cannondale featured on this forum. The bike has prob never done more than a few hundred yards, there’s no wear or marks on anything. Consequently the shifter has lain idle for over 20 years and although the levers move well and everything looks pristine, the internal ratcheting doesn’t work.
Its been sprayed from every angle possible and left for days/weeks with the occasional encouragement and gentle tug at the cable but no joy.
I don’t want to disassemble it myself.
Ideas?

 

[ChromeChainstay]

curious

is it in the the largest cog, with max cable tension?

probably not

 

[Jonny69]

I think you’ll have to take this apart. It’s the only way you’re going find what’s stuck and you’ll be able to clean and re-grease everything. It’s just ratchets, pawls and springs inside. Nothing particularly complicated.

 

[pigman]

I think you’ll have to take this apart. It’s the only way you’re going find what’s stuck and you’ll be able to clean and re-grease everything. It’s just ratchets, pawls and springs inside. Nothing particularly complicated.

No personal experience, but I've heard Shimano is virtually impossible to dismantle. Note, I said virtually, as I guess it's not absolutely impossible, but probably not one for the DIY enthusiast, especially on a first attempt.
Campag on the other hand is quite a straightforward dismantle and reassembly

 

[Jonny69]

No personal experience, but I've heard Shimano is virtually impossible to dismantle. Note, I said virtually, as I guess it's not absolutely impossible, but probably not one for the DIY enthusiast, especially on a first attempt.
Campag on the other hand is quite a straightforward dismantle and reassembly

Same, I've heard modern Shimano doesn't come apart easily, but it looks like the older stuff does. Only reason I posted what I did was because when I looked up what the shifter was, the first result was this video:

My usual advice with these sorts of things is watch the video carefully and take lots of pictures as you go so you remember where everything goes back on. It doesn't look like you'll need to take any of the ratchet mechanism apart, just clean it out with WD40 with a toothbrush and rag and get lots of new grease into it. Only tricky bit looks like getting that final spring into place

 

[pigman]

A selection of small pointy nosed, curved pliers are your friends for these jobs