I'm setting up a bike with brifters for the first time (105 9 speed (st-5500) shifters shifting a Dura Ace 7700 derailleur over an Ultegra 9 speed cassette), and the right shifter is driving me crazy. It works 100% fine with no cable in it. It works 100% fine with a cable in it and me pulling the cable to create cable tension. When I add cable housing is when it all goes to hell, and doesn't want to upshift (into smaller cogs). It does this both with the cable running all the way to the rear derailleur, and with me just pulling on the cable where it comes out of the housing on the downtube stop. I've tried different cables, different housing, longer housing, different ferrules, and a full cleaning/relubing of the shifter. Nothing has worked.
Anyone have any ideas? I would think that if it was a lubrication issue, the shifter wouldn't work with no cable, and I would think that if it was a wear issue, it wouldn't work with me putting tension on the cable. I'm stumped.
2004 LeMond Buenos Aires, 1982 Bianchi Nuova Racing, 1986 De Rosa SLX, 1991 Bridgestone MB-1, Guerciotti TSX, Torpado Aelle
I have very little experience with STI levers, but I did read the extensive comment on the YouTube video about flushing the lever out with WD-40. Awhile back I ended up purchasing something on eBay from Bikemanforu, who has a lot of videos on YouTube (he and his family are funny). Anyway, there was one in which he got a gummed up Deore XT Rapid Fire lever working again by spraying CRC Brakleen into it.
check your cable housing to make sure that you dont have any kinks in it.
check that your cable has no kinks.
that you are running shift and not brake housing.
stop into your local shop, with your bike and a pack of beer and you will be in and out faster then making a video.
Not enough tension on the cable, use more leverage... RD probably has a spring tension adjustment, take it apart and put the spring in the tighter position. Shifter is probably gunked up too, keep cleaning it out and lubricating it.
What you're seeing is a symptom of tired 9s STIs, where the return spring for the upshift lever doesn't stop it from moving a bit when you hit the downshift lever, causing the mechanism to jam.
I bet if you grow another hand and pull on the cable while holding the upshift lever against its stop, and hit the downshift lever, it works.
The weird part is how threading your cable through the housing makes the difference between this fault occurring and not... seems like it's only just happening, with the slight difference in force caused by the housing making it show up.
Goes to show, at least for these 9s ones, a demo off the bike proves nothing.
I repaired this fault in some ST-6500s by tweaking the upshift return springs stronger and the downshift return springs weaker, but it's major surgery and the results weren't entirely satisfactory.
Sadly, I believe your lever is virtually toast. Unless you're game to try your hand at STI wrangling... more watchmaking than bicycle mechanics.
If so, check the link in my tag for more.
ETA: I just figured out the weird bit - when you're pulling on the bare cable, you're helping the upshift lever's return spring because the force isn't balanced by the pressure of the housing end. This prevents the upshift lever from moving so much and jamming. This doesn't explain why the lever works with no cable, though. Subtle and tricky stuff...