KenCarlson

I have a road bike with a Shimano 6703 groupset (10 speed triple) where the right (rear) shifter appears to be broken. The failure was sudden, where everything was working fine, and then all of a sudden after one downshift the shifter now won't pull any cable past the first two clicks. I've disconnected and removed the cable itself, and that is in good condition. With the cable inserted in the shifter and coming out the other side (but not threading through any housing at all) I can pull gently on the cable while attempting to shift, and for the first two clicks the cable is pulled. Once I get to the third click, almost nothing happens anymore. I can feel a very slight bit of resistance when I should be feeling the third click, but the cable no longer moves at all. I'm imagining that there is a toothed cam inside the shifter that clicks against a pawl, and it's as if all but the last two teeth on the cam have been broken off. This is definitely not either of the two main failure modes of brifters that I am aware of: 1.) it's not a broken cable head stuck inside, and 2.) it's not a case of a gummed up mechanism. I replace the cable once a year and do a WD-40 flush at the same time. I've never had to pull out a broken cable head, and the mechanism always works smoothly since I know to keep it clean. And up until the sudden failure it was working flawlessly. So is this a known failure mode? If so, is there anything that can be done? (I've read about the hazards of working on brifters to try to do anything beyond flushing with solvent.) The shifters are 8 years old, about 16k miles, so I suppose I got a reasonable amount of use out of them, so is this just the end-of-life for these brifters?

Assuming that this brifter is toast, I've been surveying my options. There appears to be little or no NOS 6700/6703 remaining for sale out there. I can buy an entire groupset for $500+ but that would be overkill just to get one brifter. There are used pairs of 6703 on Ebay, but I would prefer to buy new figuring used brifters of that era are old enough the they may be near the end of their life already anyway. It looks like I could substitute a set of 105 5703 brifters, as I see those for sale new at not-unreasonable cost (although I only need the right brifter, I'd probably spring for both just to have a matching set). I've heard good things about microshift brifters also, so I suppose that would be an option. Although I do like the hidden cable routing of 6700/6703 (I don't mind the yearly cable replacement required for those shifters), and it looks like the microshift options have the shift cable coming out the side of the brifter like 6600/6603 did. I'm not sure, but does 5703 have the hidden cable routing? Are there other options I should be considering? As of now I'm not considering using this as an excuse to switch to 11-speed since then that would mean new cassette, chain, rear der, new 11-speed freehub since my current is 10-speed, plus I don't like any of the 11-speed cassette options because basically all of them start with an 11T cog and that cog would be useless to me, meaning I'd effectively still have a 10-speed setup after incurring all that extra cost.

So have I covered all the bases here? Anyone have any words of wisdom for me? Or should I just pick between 5703 and microshift and be done with it?

Thanks,
Ken

jimc101

I gave up with 6700 series after a few STI failures, Shimano was new to the underbar cable routing, and this first gen was pretty bad, my failures sound similar to yours, and at a similar distance.

I went to 11 speed (6800) after 6700, being as you want a triple, this isn't an option. If I was in your position, and wanted to keep the triple (once you throw in the 11 speed hub/new wheel, it's getting an expensive repair), would be looking at Tiaga (4703) knowing that the RD would need to be replaced as well (If you have done 16k on your current one, it has had an ok service life.

Tiagra (4700 series) also has the advantage of the better ergonomics of the 6800 series (although still a bit behind the latest R8000) and as there was a minor re-fresh this year, 4700 doesn't seem to have a replacement in the works just yet to hold off for.

If you really don't want a 11t on the cassette, forget 11 speed as an option, as almost all 11-speed cassettes are 11-xx, trying to find a 12-xx is hard to impossible (I've failed to find one as yet)

Sasquatch16

Wouldn't totally give up on eBay. I recently sold a slightly used pair of 6700 shifters and their was a lot of competition. Mine went for $175.00 for the pair and they were perfect.

ridelikeaturtle

I've got an ST-6700 RHS shifter sitting here doing nothing for me - I had to buy a pair a long while back to replace a buggered LHS shifter.

It's yours for 50eur + postage from Ireland, if you want it.

jimc101

You did well selling them, thinking there is a difference between people who want Ultegra on their bike, and people who have actually used it, similar to Dura Ace 7900, widely regarded as the worst Dura Ace ever, yet people still lap it up, even 7800 falls into this, esp the FD's, they can go for good money, but having put distance on a couple, they all corrode and fail in the same way, just that it says Dura Ace on it will get it to sell, and probably at a premium.

KenCarlson

Thanks for all the advice everyone. I've decided to stick with 6700 and I've taken up ridelikeaturtle's offer for his spare he has sitting around. Should be back on the road again soon!

-Ken

KenCarlson

While I was looking around, I did see that Shimano has an Ultegra 14/28 11 speed cassette:
https://www.coloradocyclist.com/shim...sette-11-speed

I don't need an 11T cog, 12T is marginally necessary for me (like maybe once a year on some long downhill run), but I would probably not be happy with the 13T missing. I do like the tight spacing that I would get with that cassette though. I'm super picky about my cadence, so tight spacing is more important to me than total range on the cassette (which is why I like a triple to get the range I need). I normally run a 12/27 10-speed cassette, but I also have a 13/25 that I sometimes use for flatter rides. The 25 cog is not quite enough for some hills, even with my triple.

-Ken

jimc101

Good find, that will be designed for junior racing, where they have limits on the size of cassette/chainrings.


Good luck with sticking with the 6700, when mine first failed, I did that, got another year or so before another shifter failure which was the point I sold my remaining good 6700 STI and went to 6800