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Bottle in front of me
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Discussion Starter #1
Hi all,

I got a set of older 8 speed Dura Ace STis that seem to be worn. The gear spacing is kinda funky in the big cog, even though everything seems to be adjusted well, and I'm using them with a Dura Ace derailleur.

I'm a semi-competent wrench, I think (but could be wrong). I've done lots of bike builds, I build my own wheels (they actually stay straight!) and the like.

My guess is that the ratchet inside has worn and is allowing extra cable slop in the most popular (to the previous owner) gears.

Can the ratchet mech be replaced in these? Are the parts even available?

I'm a fairly DIY kinda guy, but if it means that I'm going to spend 500 hours to locate parts and install them correctly, then chase down why they don't work just so, then maybe its time to pony up for a whole new drivetrain. The thing is, I'm broke, so the chances of that are pretty slim.

Option two may be finding 105 parts if they fit, and replacing my derailleur as well, since the DUra Ace 8 speed pull ratio is different than everybody else's pull ratio. My derailleur pivots seem kinda sloppy as well.

Any opinions are appreciated.
 

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How about just a new 8 speed STI unit from ebay? Too expensive? My experience with DA SIS Downtube shifters is that the index unit in the rear shifter wears out eventually - use, water (rain) and salt (sweat) are not its friends.
 

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No user serviceable parts inside

There are those who claim that they have rebuilt STI shifters, however they are never heard from again after making these claims :) In order to rebuild them, you'd have to find spare parts, which would mean cannibalizing damaged units - Shimano doesn't sell them. Those still with us who have attempted this generally report that it's not a feasible undertaking. The one thing you can do is to flush the unit with WD-40, TriFlow, etc. while working through the gears. That often restores crisp(er) shifting. Obviously, you have to be sure that your cables and casings are in good shape and that the lever hoods are not interfering with shifter operation.
 

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Try a Shimagnolo bike. Go to Sheldon Brown's site for a good article on combining the two. It sounds like you need a new rear derailleur & a new shifter anyhow, so if you've got to buy them, at least consider Campy. While you're at it you can upgrade to 9 or 10 speed. Put a Wheels or American Classics cassette on that Shimano hub (it should fit right on) and you should be set. Crankset and FD should work with the Campy Shifter. Then you can rebuild your shifters to your heart's content!
 

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Bottle in front of me
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33 Posts
Discussion Starter #5
Pepe said:
Try a Shimagnolo bike. Go to Sheldon Brown's site for a good article on combining the two. It sounds like you need a new rear derailleur & a new shifter anyhow, so if you've got to buy them, at least consider Campy. While you're at it you can upgrade to 9 or 10 speed. Put a Wheels or American Classics cassette on that Shimano hub (it should fit right on) and you should be set. Crankset and FD should work with the Campy Shifter. Then you can rebuild your shifters to your heart's content!
Uh, like I said:

pimpbot said:
The thing is, I'm broke, so the chances of that are pretty slim.
 
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