slickhorn

just wondering if anyone has a trick to share....

I have brand new sora 2/3x9 sti shifters. went to mount them today, first time sti. did the right first, no troubles. checked the action on both after mounting, before cabling and all was well.

when I went to finally attach the front derailleur cable, the left shifter would not downshift.

these were working smoothly half an hour ago. never ridden, and haven't been out of my sight. I've tried putting pressue on the cable, so its not a slack downshift attempt, but no luck. the thumb lever seems to articulate just fine, but no downshift. I can't even get the cable out!

Any suggestions?

Thanks folks!
-b

dddd

I recently had to throw away a Shimano MTB shifter that locked itself in high gear, similarly while it was being moved from one bike to another.

It was as if the shifter being shifted to, or past, the point of greatest cable pull resulted in the shifter not being able to downshift.

This was a $90 pair of shifters from the midlate 1990's in perfect condition until I shifted it with the cable having no tension on it.

I couldn't believe it. The shifter is dead. The actual shift mechanism on my shifter was completly non-serviceable, no threaded fasteners at all, and no view of the inside. This seems so much like a deliberate black-box failure engineered into the modular shift mechanism.

In my case, the release lever actually locked up as well, and I eventually slapped it hard enough to release the cable, but the shifter would then skip a gear while shifting toward the smaller sprockets.


I have known road STI left shifters to lock into high gear, but only as long as excess cable tension froze the mechanism.

Kimmo

IMO it's almost certainly not broken... perhaps it's shifted too high and become stuck, or maybe the downshift lever's pawl isn't engaging due to a sticky pivot.

Keep fiddling with it; maybe it'll come good. You could try a squirt of WD40 if you get desperate...

slickhorn

So, it looks like although the cable end was seated properly, it worked loose a little and was out of position. This led to things getting fouled, but I was eventually able to clip and free the cable head and all is working.

whew, I was rather terrified ...

-b

bobotech

I was thinking that was what happened. Those STI shifters do not take well to there being shifted while the cable is slack and the cable stop isn't perfectly seated. Has a tendency to lock up shifters as you found out.

AlphaDogg

Happened to me the first time I replaced shifter cables on my 105 set.

Kimmo

Ah, third possibility. Noted.