joedab

There's an old Gary Fisher hardtail that's still my go-to for mashing around the mountain trails, but recently it developed a problem of skipping from one gear to the next while pedaling. My best guess is a wobbly derailleur pulley because it will still ghost shift no matter the amount of back-and-forth on the barrel adjuster. Also have a new chain and cassette in hand, but also reminded of the long-term problems with shifting and think it's time to start replacing parts.

I am not usually one to give up on older parts that may just need some maintenance, though the current ST-M566 Deore XT trigger shifters seem to be notorious for issues down the line. The main issue with these is that for whatever reason, the levers have become extremely difficult to press toward the larger cogs, no matter how much housing I replace or parts lubed. My impression is that issues with these are extremely difficult to resolve.

I have not shopped for shifters in some time and do not even know the standard for modern mountain bikes, but there seems to be a dearth of options that appear as solidly built, but appearances can be deceiving. With a quick scan on ebay, I zeroed in on these as one of the more promising options. Does anyone have any experience or others I may not yet me familiar with? It is easy to unbolt the current shifter assembly from the levers, and so hope to find others that would slip on the bar along side (or even bolt onto) the present levers.

Along with a chain, cassette and new shifters, it would seem incomplete not to consider the derailleur, though its part may not be any more than a worn ceramic bearing. The crucial bit about shifting to higher cogs seems to relate more to the shifters with both sides being equally difficult. The spring on either derailleur seem to have no excess tension and actuate smoothly enough. An initial diagnostic would probably be the ease of shifting with new levers and a new pulley of course and then go from there. Anyone have a source for a good g-pulley?

dsbrantjr

That bike has clearly (and unsurprisingly) been knocked around quite a bit during its life, judging from the wear on the drive side chainstay. Have you checked the derailleur hanger alignment and checked for a bent derailleur? A fresh set of cables, both inner and outer might also be in order.

2cam16

If you're looking to replace components, I'd try going used period correct. There are quite a few out there on EBay.

AnkleWork

As advised first check the derailleur hanger alignment and cables. You're not going to find better shifters -- yours probably only need thorough cleaning and lube. Then maybe replace the chain and see if it still skips. If so then replace the cassette.

If you still want to replace everything, just because, I'll buy the shifters from you.

joedab

Indeed the cables and housing have been replaced many times. The bike has also had regular concurrent replacement of the chain and cassette, however the bushing on the g-pulley has a degree of sideways play that would allow the chainline to sway.

The derailleur hanger has also been checked and maintains uniform distance from the rear rim.

Going with period-correct componentry is something I have definitely strove to maintain, although nothing currently mounted is original except the brakes and bottom bracket. The issue with sourcing another set of these shifters is not only price but reliability. I have looked into overhauling these, but from what I gather, this is not very accessible to say the least. I have tried oiling the pal and ratchet mechanism while working the gears back and forth, but I cannot seem to shake the extreme force required for shifting to the larger gears. It seems worth trying a contemporary set if only for diagnostic purposes to see of the foreboding tension/friction is actually based in the shifters.

Bill Kapaun

Found any RDER's where the Guide Pulley DOESN'T have a bit of side play?

dedhed

That's what it's designed to do. It allows for slight misalignment in your indexing and promote quieter running.

Jeff Wills

Have you tried taking the plastic covers off the shift levers and washing out the insides with spray lube? Given that these are 25 years old I would bet the grease has hardened and is making the "push" action very stiff.

A worn rear derailleur is also possible. I recall wearing out a Deore XT rear derailleur of similar vintage and it was not as smooth as it was when new. It still indexed properly, but a sideways push on the cage showed that the pivots had considerable play.

I assume you have an 8-speed system. Here's similar (not identical) shifters available on Ebay: https://www.ebay.com/itm/SHIMANO-Deo...S/123848166193