alden

I just got my new Shimano 105 5700 shifters delivered. Got them out of the box, looked them over, and everything worked and looked good. Once I got the cables installed and everything clamped on the bars the B lever on the right (rear derailleur) no longer wanted to work. It will push as far in as it goes before it clicks. Sometimes it rolls the mechanism back, but most times not. The A shifter works fine. As I was trying to find the problem the B lever got progressively worse so that now it won't work even sometimes.

Has anyone experienced this problem? If so is it fixable or should I just send it back?
Bear in mind I have not fiddled with the mechanics, other than turning the allen screw located on the underside of the shifter by the clamp. (I thought this might be a trim adjustment, am I wrong?)

HillRider

Try this first:

1. Disconnect the cable at the rear derailleur.
2. Push the inner lever at least 10 times to be absolutely sure the shifter is in the highest gear (smallest cog) position.
3. Pull all of the slack out of the cable and reattach it at the derailleur.

See if that fixes it.

Retro Grouch 

The very first thing that I would do, even before Hillrider's suggestion, would be to put the shifter back into the default condition. That means un-doing whatever it is that you did to the allen screw located on the underside of the shifter.

alden

After further investigation I found that that allen screw on the underside of the shifter actually holds the various parts of the mechanism together. It extends up through the center of the parts and is secured to a nut at the top, behind the brake cable inside the housing. I don't think this screw was secured when I got it, because the problem starting before I tried to adjust anything. Once I got this secured properly, and got the cable drawn nice and tight like HillRider suggested (thanks btw) it works beautifully. Just as an insight that bolt is also held in place with a set screw that takes a 1.5 allen key. It's worth making sure it is tight to prevent the bolt from vibrating loose. The one in mine wasn't and may have allowed that bolt to come free. Thanks for your input guys.

Kimmo

By the sound of it, either STIs have changed a great deal, or the above post is all kinds of wrong.

A 1.5mm allen head bolt (apparently in a vertical orientation) holding the mechanism together? That's a whole differnt animal to what I'm familiar with.

Bike Gremlin

My 105 5703 brifter for frond chainrings (left one) stopped working for no reason after some 50 kilometres. Maybe it was a bad piece, or the whole 5700 series is to be avoided? Have you fixed the problem?

Kimmo

Ergo FTW. STI is poo.

Jury's still out on Doubletap, AFAIK

Retro Grouch 

I don't think so. I've personally never encountered the "tiny screw loose" issue but I've read some other good bike mechanics who reported it. That's why I mentioned it in my post.

jimc101

Broad statment there, having done many thousands of KM on STI's and Ergo, both work just as well as each other, never tried SRAM, so can't coment on that.

Retro Grouch 

That's what I was thinking too. There's an awful lot of bikes out there using STI shifters. I'm thinking Shimano wouldn't be able to maintain their majority market share if the huge majority of riders weren't essentially satisfied.

alden

These pics are tough, but if you look close you can see the post that goes up the center of everything. That hole directly below the arrow is where the small set screw is. I wish I took pics of everything when I had it apart. It all works now however and is installed on my bike. I don't want to tear it all apart now.

HillRider

I've not worked on 5700 brifters but on 8 and 9-speed 105 brifters, there is a small allen head set screw installed vertically head-down under the shift mechanism. It acts as the retainer for the brake lever pivot pin and you have to remove it to take out pivot pin to remove the lever/shift mechanism from the brifter body. It has nothing to do with the shifting itself.

Nonsense. I've had 105 brifters run flawlessly for 10's of thousands of miles and most of the people i ride with have had stellar service from all levels of STI brifters. Yeah, Ergo is very good and I've got them on two bikes but a blanket dismissal of STI is foolish.

Kimmo

Hands up who's overhauled both STI and Ergo.

/hand

Yeah, of course I knew that, but I was thrown by the description implying it had something to do with the shifting, plus the fact I haven't had a play with any of the new ones without the exposed cables.
...Which I'm tipping are even more horribly complicated.

Ergos are amenable to rebuild, repair and even modification, but I take my hat off to the man who can just fully comprehend Shimano's demented clockwork. All made of bent steel plate even on Ultegra, yum.

It's as if - and I think I may be onto something here - they got the guy who does the fishing reels to come up with STI. It's just not... proper bike tech somehow, IMO. Campy's stuff is far more... appropriate.

And don't get me wrong; I'm not prejudiced - IMO just about everything else Shimano does is better (particularly their rear hub), with the notable exception of the styling on their dead squid cranks.

alden

At first I thought "it had something to do with the shifting". After further exploration I found it really doesn't. However if it's not tight then the mechanics are too loose and won't engage properly. Admittedly I'm not a mechanic, just here looking for advice and sharing experiences.

Kimmo

Sounds a bit different to what I know of the older ones... having a hard time making out much in that pic, your camera needs more light to make less noise.

The little allen screw secured the pivot pin for the lever, and that was it. Just bit up against a thinner section in the middle of the pin.

The lever would work as normal until the pin worked its way out of place.

HillRider

No question STI's are inscrutable and are use-until-they break-then-replace items. There are a couple of posters here who claim to repair them but have to calibalize others to get the replacement parts. However, my point is that, in my experience, that failure is a long time coming.

Ergo, at least through the '06 10-speed versions of Record and Chorus I have (pre-Escapemant, QS and the other "improvements"), are indeed rebuildable but I don't know if the current 10 and 11-speed versions still are. I've read they are not.

alden

This is my shifter, the second pic is the small set screw, the third is the allen screw on the underside of the shifter (by the clamp). The screw undernieth was the one that was loose, and as a result the various parts were not sandwitched together tightly and not engaging properly. It goes straight through the center of the machanics and attaches in the top of the housing behind the brake lever. It would seem to me that the smaller set screw is in there to keep the larger screw from loosening, and it too wasn't tight, and may have been the cause.

Kimmo

AFAIK Campy no longer does small spares, but I'm pretty damn sure Ergos remain rebuildable, since they still operate on the same principle (indexing devolutions aside).

Worse, use-until-they-gum-up-then-replace-if-WD40-doesn't-help items. They don't even have to break to be kaput.

Kimmo

No wonder I was having trouble making it out, it's a whole new ball game. So the indexing mech's housed inside the body and not the lever now?

alden

Yes, from what I've gathered online and in magazines this is "trickle down technology" from Dura ace. Is that true? I've never seen a Dura ace shifter disassembled.

HillRider

What good is rebuildable if replacement and repair parts aren't available?

Oldpeddaller

Shimano fishing reels are truly excellent - I was lucky enough to be bought a Triton Speedmaster TSM11FSC beach multiplier new about 25 years ago - they were only released for about six months on the UK market and it's still by far the best beach reel I've ever used - and I've had the lot, ABU, Daiwa, Shakespeare, Zebco, Penn - and the rest.

Which is why I was disappointed when some beautifully preserved RSX and RX100 brifters came my way - and didn't work at all. However I've blasted three out of four clean and squirted teflon lube inside and they work. The fourth has a small piece of frayed cable and it's nipple jammed inside. So tomorrow I'm going to strip them down (first time I've ever tried this) according to these posts

https://www.bikeforums.net/showthread...%29-STI-Levers
https://www.bikeforums.net/showthread...%29-STI-Levers

and lube them properly while removing that pesky cable - how hard can it be?

I've been a Campagnolo fan for over forty years (and still am), but in the current recession I can't turn down quality parts by Shimano, Suntour, Huret etc. that come my way for free! (Translation = middle-aged tight wad!)