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Curtiss
09-06-2008, 02:45 PM
I recently bought a used bike with 105 STI shifters. I'm not sure the left shifter is working correctly. It's a 9 speed triple, ultegra derailleurs.

The left shifter has four positions. As I understand it, it should be adjusted such that 1 is the inside position and 4 is the outside position, 2 and 3 should be slightly inside and slightly outside of the middle chaingring respectively.

Problem is, when I'm in 3 (middle, outside) and want to trim to 2 (middle, inside), there is no half-click click available. I can only release all the way to 1. Both stops are set correctly.

Question is, should I be able to click from 3 to 2 when properly adjusted? That is, is the shifter broken?

I've tried to overcome this problem by setting 1 and 2 as inside/outside positions on the inside chain-ring, 3 in the middle, and 4 on the big chainring. This way a shift from 3 to 1 puts me in the small chainring and if it's rubbing (because I'm cross-chained (which, of course, I shouldn't be)) I can just trim to 2. Unfortunately, even with the stops properly adjusted, set up this way position 4 rubs on the chain (rubbing on the outside of the chain). Also, without a trim, I don't have the range I'd like in my middle chainring.

I also read somewhere that 3 and 4 should be set up as inside/outside on the large chainring?!!? Seems people are all over the place on this.

Would one of the very knowledgable people who monitor this forum be willing to help a kid with some free advice?

djasonpenney
09-07-2008, 09:07 PM
...have you had previous experience with the Shimano triple chainring system before?

You'll find that you can't run cross-chain into all the rear sprockets without grinding the chain on the front derailleur cage, even if it's adjusted correctly.

In the small chainring, you should have easy access to the largest sprocket (let's call it #1) up to about #4. With one click of trim, you can get up to perhaps #5 or #6.

In the middle chainring, I think...it's late at night and I don't want to run out to the garage to check this...you have clean access to all nine sprockets.

Conversely, in the large chain ring, you have access to sprockets oh, about #4 through about #9.

If I read in between the lines of your post, are you concerned because you can't get all 27 gears to work cleanly? If that's what it is, don't worry, it's a "feature."

--jason "don't get me started on how stupid the gear ratios are on the stock Shimano triples" p.

Curtiss
09-08-2008, 04:41 AM
are you concerned because you can't get all 27 gears to work cleanly? If that's what it is, don't worry, it's a "feature."

For real man. Totally strange. I've ridden the same Rockhopper XC with Suntour thumbies since 1993 -- every day to high school, then college, then law school, and now to work. IMHO, a friction left shifter is vastly superior.

I did, however, figure out the 105 STI shifter (the wife and I bought used road bikes -- a Brave New World). Though nothing on the interwebs told me so, turns out there are five positions on my shifters. I had the cable too tight (and probably the high stop screweed too far in). I'm still dialing it in, but now I have 1 on the small chainring (resting on the stop and the cable pretty loose), 2 is a small click in (mostly taking the slack out of the cable and pushing the derailer a little way), 3 slightly inside the middle chainring, 4 slightly outside the middle chainring, and 5 sitting on the large chainring. Seems I only have about 3 gears in the rear cassette when in the large front chainring before it starts rubbing. However, I believe that's probably the "feature" you speak of.

I believe 2 is actually some sort of trim for the small chainring and that the shifter is "supposed" to skip it when shifting from 3 to 1.

Hopefully, this post will be useful to the next person with this problem, because I sure couldn't find anything similar online.