louky

I recently bought an early/mid 90's Trek 520 with issues on MP. It has Shimano RSX shifters (which I understand may not have come originally on this bike). I have never worked on this type of brake/shifter combo before and have been doing some research as they both are gummy and not shifting. The bike had a tacoed rear wheel and apparently has been sitting for years. When looking this over and trying to get some WD40 sprayed into them I noticed a visual difference between the L and R shifter when the brake lever is pulled back. The R is completely covered but on the L, the mechanism is exposed like the included picture (not my pic but identical). My question is if this is normal? If there are parts missing and I have to shop for them, it might change the direction I will be going with this bike. Thanks in advance!

I captured this from Ebay, mine looks like this.

andrewclaus

Someone worked on it, or tried to, and broke off the plastic cover. And I think I can see the reason. One of the ratchet pawls, a claw-like piece, looks like it's sticking straight out. It's supposed to have a torsion return spring. If that's broken, the shifter is toast. You can see the coil of the spring at the base of the shaft.

If there's a bike co-op in your area, they may have a salvaged replacement shifter.

Mid 90s is the right time frame for those RSX shifters.

louky

Thanks for the prompt response. It's kind of what I expected but not what I was hoping for. I will focus on getting the LH working. If I am able to, I will try to match the RH. If not, I will start from scratch. Any suggestions on new lower cost shifters of this type? If I have to start from scratch, should I go back to bar end shifters? This bike is likely to big for me and will end up back on MP, once I get the rear wheel sorted. I will try to get a pic of my actual shifter posted since the pawl on mine is not sticking up like this. If I can get my RH working, maybe I can shop for a shifter that may not work but has the cover. How is the cover held on?

andrewclaus

If there isn't a co-op near you, check on eBay for used shifters in working order. A quick glance shows them starting at $100/pair. New Microshift pairs look less expensive than that, and others have had good luck with them.

I don't remember how the cover is attached. I think it snaps on but the tabs get brittle and care is needed. There may be a YouTube video showing disassembly. As I recall, left and right are different.

louky

Yes, it appears that the left and right are different, and the YT I found on this (so far) was doing the right. I have included a photo of my actual LH shifter (as opposed to the screen capture in the OP. Are you seeing anything obviously wrong with this one?

I am going to approach this slowly and see if I can get this one working (sans the cover). This would allow me to shop for one at the co-op or from ebay that is complete but inop. If I am able to get the LH working, I will then tackle the other. I have freed up a lot of the MB combo brake and shift setups with just spraying and working the pawls. I have had some that the pawls had to be forced dozens (maybe hundreds) of times before they finally break free and once they break free they seem to work fine.

louky

andrewclaus

If you've worked the pawls on other shifters, you're all set to tackle these. You may need to remove the lever/shifter from the body to access both pawls. That will require loosening a small Allen set screw and punching out the pin. Assembly is harder with the torsion spring, and there's a knack to it. Again, YouTube may help. Once it's exposed, try some penetrating oil, just a few drops, on the pawl shaft. WD-40 is a good solvent, but not so good a penetrant. Then go at it with the dental pick.

I had missed your note that your first photo was not your shifter. Yours at least has an intact torsion spring at the upper pawl. Good luck.

I've put or kept these in service without the cover for free or inexpensive bikes at a non-profit shop. It's partly cosmetic, at least most of the time.

louky

Following up: The LH shifter freed itself up since yesterday's soaking with WD40. I cycled it 20 or 25 times and then lubed with tri-flow. Other than the plastic cover I think this one be OK. I'm still not sure how this cover attaches. I did find a YT where the person disassembled a LH unit but it looked like he completely took it apart (even taking the lock nut off that requires a special wrench) and still didn't show removing the cover.

There is an extensive YT by RJ the Bike Guy on the RH and I feel confident I can get it down as far as he shows, giving full access to the pawls. I saw the tool he used to help align the spring to reassemble but some people suggested a properly sized roll pin in place of the tool, which I will try first.

BTW, the Front derailleur seems to take a whole lot of pressure to shift up. I've lubed the pivot points on the derailleur and checked for free movement in the cable. The shifter doesn't feel that hard to shift when not hooked up. I was doing this with the bike in the stand and I don't have anything to compare this to as I have never worked on one of these shifters before. It just seemed like it took much more force that a similar thumb click shifter.
This is with the chain not in place.

andrewclaus

Replace the cable housing. It's probably pinching the cable at the ends when under compression. Pull off a ferrule and you might see that. Replace the cable(s) while you're at it. And if you haven't installed new housing, check out Sheldon Brown's site for instructions. A poorly routed or improperly sized housing could cause problems too.

Troul 

The spring here looks suspect. Is it suppose to have that gap between the paw & it's last coil?

andrewclaus

The OP says in the first post that photo is not his, it's from another site. I missed it too and had the same question.

louky

Yes, I posted my actual shifter further down the thread. The good news is that I was able to get this freed up and working. I switched over to working on my RH unit for the bad news.

andrewclaus

Yeah, that's bad. And it's a failure I haven't seen.

louky

My guess is that somebody forced it after it quit working initially. Since the bike is new to me, I will never know for sure.

louky

Following up: I was able to get a set of these at the bike co-op for $15. The RH was gummy and not working but I disassembled, cleaned, and lubed. It is now working fine. I had previously freed up my LH shifter but it is missing the plastic cover. The LH I got at the co-op is inop, but the plastic cover is intact. I took this apart but am not seeing how to get the plastic cover off, at least not without removing the nut with grooves in it that takes a special tool. Am I missing something here?

louky

It looks like the tool required to take this nut off is no longer available. Is there a hack for this?

andrewclaus

In this video, the plastic cover is broken, and then glued back on for reassembly:
I guess there's a reason the original one was broken, and why I sometimes see them missing.

Thanks for the update.

KCT1986

The tool to remove the nut in the back is hard to find. The more modern brifters don't seem to use this same 'castle' shaped nut.

Some people on here have fashioned their own tool out of a hex socket. 8mm socket is an option, it needs to have an outer diameter small enough to fit between the prongs of the brake cable holder bracket.

See post #47 in the attached for an example.

Ultegra 8-speed brifters, opinions - Page 2 - Bike Forums