wrk101

OK, 99% of what I work on is either DT shifter or barcon. But I have picked up a few Shimano STI bikes, and must be messing up the install.

On the last five bikes I have had problems, 100% of the time, its always the front shifter. On one bike right now, I can get it to shift up to the big ring, but not back down to the small ring. On another (RSX), I am getting three solid shifts (triple), but on the big ring, either I get a lot of rub, or it just doesn't make it. On the RSX bike, I just had the shifters rebuilt, so they are good. And when I am 0/5, I suspect mechanic (me) error.

I think I have these guys zeroed out. I just replaced a nine speed Ultegra front, with a used DA nine speed, same problems, same symptoms.

I need to figure this out. Next step is downloading the PDF Shimano instructions (I know, I should have started there)...

wrk101

Some details of the process I use.

1. I adjust the low limit and cage position without the cable attached.

2. I make sure (or I think I make sure) shifter is zeroed out by shifting several times to get it in the low position.

3. I attach the cable. It is usually routed over the top of the leverage tab, and then attached horizontally (there is a groove in the attachment point).

4. I adjust the high limit after running the derailleur through multiple shifts up and down (assuming it works).

Puget Pounder

You probably left this out, but what about tension? Are you using thinner ramped rings?

oldbobcat

On the first bike, the cable is pulling the cage too tight against the high limit screw. Let out a little cable tension or let out the limit screw and re-calibrate. On shifting to the big ring, the cage should lightly kiss the limit screw as the shifter ratchets into the outer position.

On the second bike it sounds like you need to let out the high limit screw a bit--try this and try a few shifts by yanking on the derailleur cable. If it works, add a little tension to the cable and fine-tune limit screw and cable tension.

By the way, both Park Tools and Shimano have web pages on derailleur setup and tuning.

zebede

is the cage parallel with the chain ? I had one 9-speed Sora brifter recently that drove me crazy for a couple of day until I tweaked the rotation of the derailleur clamp a bit and voila. The symptoms were very similar and it was off a very small amount.

Sean Gordon

All the advice on setting up the derailleur to shift properly first is golden. Limit screws, proper height angle, good cable routing and lubrication of pivots and springs have to be resolved first. In regards to FD height, the outer cage should clear the longest teeth on the big chainring by just a few mm. IE, when the chain is on the big ring, you should not be able to move the FD inward to flex the chain without turning the cranks. The closer the FD to the chainring, the better the shift, especially with large steps between chainrings.

Some shimano front derailleurs actually swing outward slightly as they actuate. This is not a design flaw, it allows for more useful gear combinations while still keeping the limit stops close. Its also important because you can't precisely trim with STI. (The rear of the cage is farther out from the centerline of the frame).

Its a very slight arc, but generally the FD will only be perfectly parallel with the chain rings in its low normal state. In regards to setup, make sure the FD is parallel with the chainrings in its low normal state. FD's that move in this slight arc (in plan view), may not shift back to the small chainring unless they are set up in this way. My FD7700, and I think my FD7800 have this characteristic.

With FD's that stay perfectly parallel, maybe try setting it at a slight angle (with the rear of the cage being 1-2mm further than the front from the centerline of the bike). This can resolve upshift problems, but you will need to let out the inner limit stop to prevent rubbing in your low/low combination.

It can also be a problem with the shifter. I have had older 9speed 105, and 8 speed 600, have backlash issues. Any ratchet mechanism has backlash, or play between the ratchet and the pawls. This manifests itself in derailleur movement in a way thats like 3 steps forward, 1 step back. Most of the time, its actually good for shifting because you need that little bit of extra push to get the chain to catch onto the big ring. However, backlash increases proportionately to wear, so your older shifters may shift up to the big ring, only to fall back down as you release the lever; further tensioning of the cable only makes the FD overshift.

There's not much you can do to overcome backlash issues except replace the ratchet and pawls, and you can't do that with shimano except for some 8 speed models and 7700 9 speed. Don't buy used low-end STI levers; most of the time you'll get them when they're ready to fail.

RT

Be sure you are looping the cable the proper direction when fastening to the FD.

I have always set my min and max at the same time when the cable is disconnected.

Not to be a wet blanket, but I have yet to find Shimano documentation that makes it worth the time taken to download it

Al1943

Use the instructions found at www.parktool.com. Do all of the steps in proper sequence leaving nothing out. The Shimano instructions are basically the same.
Hose out the shifters mechanisms with WD40.

Sean Gordon

I would only flush the shifter internals with solvent if they stopped working, IE not letting any cable out. This is a last resort fix for a worn-out STI. You'll never be able to get lubricant back in there after you wash it out. I've had to do this a few times and it usually frees up the mechanism for a little while before complete failure occurs a week or two later. (this is on a cross bike though).

Al1943

WD 40 will not do any harm to shifters. My 1998 Dura-Ace shifters nearly quit after 4 years. WD 40 totally restored them to good shifting performance and they are working perfectly today. I've known of many cases of WD 40 restoring good performance to other STI shifters.

wrk101

Shifters themselves work fine. Its just not moving the cage far enough. It got a lot better when I raised the cage a bit, and rotated the rear out very slightly (as someone above pointed out). So right now, I am only getting rub on the highest gear, on the big ring (RSX triple). Will keep playing with it. Reread the Park tool site instructions a couple more times.

Sean Gordon

Right, but its a last ditch repair. You want the factory lubricant to remain in the mechanism as long as possible.

wrk101

Success, sort of:

Bike 1: Novara Randonee, 7 speed RSX, triple front. The bike came with a Shimano 105 FD. I finally pulled the only other triple FD I had in hand, a SORA unit, and did a swap. Instant success, no more problems. Not sure what was wrong with that 105 triple FD, but the SORA works great.

Bike 2: 1989 Cannondale R400, came with 8 speed Shimano 105, double front (yes, I know this is not original, bike was a mess of misc parts). Since changing the FD on the Novara worked so well, I decided to do a swap on the Cannondale as well. So I pulled off the Shimano 105 FD, and replaced it with the only double brazeon FD I had in hand, a RX100. Instant success. I ended up pulling off the eight speed rear off the Cannondale, it was really jammed in, a very tight fit, on a late 80s Cannondale, and put in a seven speed rear instead. Right now I am keeping the 8 speed Shimano 105 brifters, limited out the rear, seems to be shifting great.

Bike 3 and 4: Quintana Roo (9 speed DA) and 1987 Schwinn Prologue (9 speed DA): Front brifters definitely not working. So I pulled a Tiagra front brifter I had in hand, instant success. I am giving the DA front STI the full WD40 treatment, as a last ditch effort to revive it. We'll see how it goes. I have a couple of other single front brifters, they won't match, but they will get the Prologue back on the road. Hopefully at least one of the 2 DA units comes around.


So far, the lesson for me is if I have other derailleurs available, make a swap there. Its a lot quicker swapping FDs, maybe 15 minutes, versus the hours spent trying to get the bike to work. For whatever reason that I have not figured out yet, the rear shifting has been much less tempermental.