Compatibility issues with Shimano ST-5703 and FD-6700



zakel

New Member
Jan 13, 2012
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I am facing problems with my Shimano 105 shifter ST-5703. I've equiped my bike with Ultegra fd-6700 (got it in good price) but ended with a no functional bike. Actually the front derailleurs is not working after a couple of gear changes and the cable is over stressed. Knowing that the ST-5703 is meant to be used with a triple crank (mine has the 105 compact version) is there any other known compatibility issue between the 105 shifter ST-5703 and the Ultegra FD-6700 front derailleurs?
Thanks!
 

swampy1970

Well-Known Member
Feb 3, 2008
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First off - what do you mean by "the cable is over stressed". Was it once easy to move and now it's sluggish? Is it difficult to make the FD just move using the gear lever or does it move to a certain point fine and then you can move it no more?

Here's the official Shimano compatibility matrix:

http://bike.shimano.com/publish/content/global_cycle/en/us/index/tech_support/tech_tips.download.-Par50lparsys-0025-downloadFile.html/01)%20Drivetrain%20Compatability%20Chart.pdf

Since you're running a compact chainset, you may be able to make it too work - you may not. The indexing for the lever may not be correct and will move the FD an incorrect distance. I'm guessing that this is more down to the installation of the new FD.

First thing to check is that the cage plates on the 6700 front mech aren't hitting the chainrings. You may need to adjust the height of the FD to get this. Shimano recommend a millimeter or two between the bottom of the outer cage plate and the chainring.

The second thing to check is the limit screws - and I think this is what is wrong. There are two screws on the top of the FD - adjust as required. See the link below.

Tech tips for up front...

http://bike.shimano.com/publish/content/global_cycle/en/us/index/tech_support/tech_tips.download.-Par50lparsys-0027-downloadFile.html/03)%20Front%20Derailleur%20Installation.pdf

If it seems as though the cable is hard to move and it's not at the limit, likely causes are:

- Bad cut in the outer cable - part of the metal casing is pressing on the inner wire - remove cable, cut cleanly and deburr.
- Cable routing is bad. Things like bends that are too tight, bottom bracket cable guides dirty, cables not properly in the BB guides, ends of the outer cable not correctly inserted into cable guides or brake levers.
- Dirt or "other stuff" in the outer cable that causes high friction. Clean or replace as required.

I've run a 7803 FD with 7800 STI levers on a double with no problems... so there's hope that the reverse combination should work.
 

zakel

New Member
Jan 13, 2012
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Thanks a lot swampy1970 for your detailed answer.
Actually when the problem occurs the FD remains at the outer position. Moving the shifter doesn't change anything (at this point the cable is inactive overstretched and if you try to make a gear shift you feel nothing when touching it) and I 'm obliged to disconnect the cable from the FD, free the inner cable and make some hits with the shifter until I hear again the characteristic click sound and then reassemble the cable at the FD. Seems as if the shifter locks...
 

Eichers

Member
Sep 17, 2010
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Hi swampy1970, if I am reading that chart correctly (quite a confusing chart), I think that it is saying that the FD5703 has the same pull/actuation ratio as the FD5603. If this is the case and I believe that the FD6700's pull/actuation ratio is the same as FD7900 then the ST5703 Shifter and FD6700 are not compatible ... is this correct?

Seems odd because the chart does not indicate ST5703 brake compatibility (ie 1:4? or 1:3 compatibility) ?
 

alienator

Well-Known Member
Jun 10, 2004
12,596
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By the chart to use a 5703 shifter, you'd need to use either a 6703 or 5703 FD. I don't know what real world compatibility is though. It's often the case that manufacturers say something is incompatible when in fact it isn't. As for the brakes, any brakes would work. There might be a slightly different feel between some brakes, but that doesn't mean they won't work. By brakes I mean modern offerings and brakes of similar tech. That is to say not brakes like old Mafacs or other odd brakes known for not offering modern performance.
 

oldbobcat

Well-Known Member
Aug 31, 2003
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Originally Posted by zakel .

I am facing problems with my Shimano 105 shifter ST-5703. I've equiped my bike with Ultegra fd-6700 (got it in good price) but ended with a no functional bike. Actually the front derailleurs is not working after a couple of gear changes and the cable is over stressed.
Whenever I hear jamming, double rings, and triple shifter in the same sentence, I suspect that the outer limit screw is a bit too loose (too much travel) and the cable is a bit too loose, which means you're shifting into the second ring using the click meant for the third one. From the small ring you want to hit the big ring solidly and the limit screw lightly with just one firm sweep of the upshift lever. If upshifts require two shifts, your cable is too loose. If you're hitting the limit screw hard with one shift, and the cable is too tight for an easy downshift, then loosen the cable before you try to downshift and break something, and start over.