Are my Dura-Ace 7800 shifters dying? Small lever unresponsive
 

When I'm trying to shift to a faster gear on the right-hand side with the small black lever, sometimes the lever will move all the way in without engaging anything. I have to jam on it a few times before it finally 'clicks'. This happens maybe one out of every ten attempts. I just had the shop replace the cable and the problem didn't go away. Am I screwed?

How old are the shift cables and housings? What you describe is typical for excess friction in the housings or somewhere along the cable. The short housing at the rear derailleur is often the culprit.

You may be able to fix the problem by shooting lots of WD40 into the shifter(s). Thick hard grease and dirt can also cause this problem. WD40 is an effective solvent to loosen and flush the dirt and hard grease out.

I doubt that the shifter is worn out. My 7700 Dura-Ace has had the same problems, WD40 and new cables and housings returned the shifters to "like new" performance.

Sounds like the same thing here
http://www.bikeforums.net/showthread...ter-repairable

I concur, but would like to add that sometimes the WD40 takes a while to work and you may have to work the shifter a bit to loosen the grease/dirt. Don't give up to quickly. If you really do need an new shifter, now that it's the end of the season, I've just noticed that STI shifters on eBay are selling at very reasonable prices (compared to last spring).

beef: Check the condition of your shift cables, both the wires, particularly inside the shifters, and the housings, especially the small loop going into your rear derailleur. Be sure the housings' ends are properly prepped and not extruding out of the ferrules, which will cause binding. Keep in mind that the derailleur spring pulls the cable in to shift to smaller cogs, the shifter does not push it out, so friction will cause the problem you are seeing. If your cable is fraying inside the shifter it would be a lot easier to replace it before it breaks than after.

Hmm. Interesting points. If my cable is brand new (I just had the shop install a new one), could bad housing still cause this? It really feels like something in the shifter's just not 'catching'. Want to know before I test the theory and buy new housing.

Also, dsbrantjr, could you elaborate about the whole idea that friction only affects upshifts and not downshifts? It makes sense intuitively, but I just want to hear you explain it more. Thanks.

edit: I should also note that this is on a used bike that I just bought, so I don't really know the history of the bike.

Is the main lever returning to its original position after your last shift up to a larger cog prior to this problem occurring?


From what I have seen with a late-model Ultegra shifter I partly dismantled recently, there is in fact not much grease in there.

beef: A new cable may not play well in a worn housing. Did the shop replace the housing or just the wire? I always replace them together, it's cheap and saves a lot of head-scratching. You should be able to somewhat check out the condition of your cable housing by inspection. Undo the cable from its anchor point on the derailleur to give yourself some slack to work with. You should be able to pull off the ferrules from the housing ends (they are present, right?) and make sure the housing ends are cut or filed square without any stray strands for the wire to catch and reamed open so the cable can move smoothly. It is shifter, not brake, housing, right? Slide the housing along the cable to feel for friction or catching.

The reason that cable friction will affect upshifts more than downshifts is that the only force pulling the cable out of the shifter is the derailleur return spring, while downshifts are accomplished by the lever action of the shifter pulling cable into the shifter, which it can do with considerable force, certainly more than the spring can exert. Without proper tension from the spring, transmitted by the cable, the shifter ratchet will not function correctly. The cable needs to pull out far enough and with enough force for the shifter ratchet to cycle properly.

Rowan: the main lever works perfectly fine. What do you mean by not enough grease? Should I put more in my lever?

dsbrantjr: The shop just replaced the wire. Yeah, it's shifter housing. I guess I'll inspect it and test out your theory. But one thing makes me think it's a shifter problem: when I miss an upshift, the black lever goes really far in; a much longer 'throw' than what would ordinarily cause an upshift to occur. Wouldn't that mean there's just something not right with the shifter?

Anyway I'll try swapping the housing first.

Try shooting lots of WD40 directly into the shifters.

If that doesn't fix it- shift the rear to the smallest cog. Loosen the cable from the rear dérailleur, slide the short housing forward on the cable and lubricate the part of the cable that runs through the short housing. Be carefull with the cable routing at the rear dérailleur. If this makes a big improvement it means you need new housings.

This is what I think has happened:

When the shop replaced the cable, they have shoved it through so that it has popped the little plastic retainer for one of the return springs in the top of the shifter assembly. It means the black plastic paddle won't return to its normal position properly, and this in turn upsets the detentes in the other parts of the shifter.

If it is this, the fix is not exactly simple, but it's not overly difficult. The issues relate to getting the main return spring back in the right place, and keeping the small spring I mentioned above in place with the plastic cover over it. It's not reallly a repair for the faint hearted.

This assessment is based on my experience with a left-hand triple Ultegra lever that I bought from eBay. Whether the issue existed beforehand, or I was the clumsy idiot who caused it when replacing the cable, I am not sure. This also assumes that late model Ultegra and Dura-Ace levers have the same assembly (but I suspect they do). The repair was quite enlightening as to how the assemblies have changed substantially since I last looked inside my old circa 2000 Tiagra levers.

My reference to grease was that compared with the older shifters, the factory actually appears to use less grease on the current levers, and therefore I suspect gumming up of the workings is not an issue in this particular instance.

However, I could be entirely incorrect on all this and it may just be a simple problem with the cable housing. Perhaps the housing that runs from the chainstay to the derailleur has been caught between the QR acorn nut and dropout at some stage, deforming it sufficiently to slow the shifts down the cogset like this. Had that happen, too.

I had the same problem especially on cold mornings. I just followed the advice to flush with WD40 and problem solved. Many thanks, this saved me over a hundred buck on replacing the right lever.

I love when this happens. :beer:

Common maintenance procedure; just did it on my XT triggers.

Suggest you dribble your lube of choice in to keep things happy; I usually use a shot of Tri-Flow...

Correct - the cable can't cause this. Hopefully the WD40 will fix it. I give it a 75% chance

At what point would one try just the WD40? Where do I shoot the WD40, down at the rear derailleur?

If it is missing the 'click' when you push the lever, it's the shift lever. WD-40 wash can probably completely fix this. I've done this successfully a few times.So have other people I know. The wd-40 goes in the shifter. The derailleur just goes where the shifter tells it to go.

Use the red straw that comes with an aerosol can of WD40. Shoot it into any and all openings you can find in both shifters. Turn the bike upside-down (this is the only time I recommend working on a bike upside-down) shoot more WD into the shifters. Let it set for awhile and then turn the bike right side up. For safety be sure to clean all of the WD off of the brake/shifter levers, and be sure there is none on the wheel rim braking surfaces.

OK will try it. But need to check the WD40, if its still in garage.