105 5700/03 FD and SRAM Shifters

wishitwasallflat
wishitwasallflat Posts: 2,927
edited July 2013 in Workshop
From several previous posts and discussions I thought I had learned two things:

1) You can use Shimano front derailleurs (FD) with SRAM shifters (and vice versa cause the cable pull is the same) but not rear Ds (cause the cable pull is different),

and

2) Shimano FDs are - generally speaking - better than SRAM models.

So ... needing a new FD I decided to get a Shimano 105 5700/5703 FD ( http://www.wiggle.co.uk/shimano-105-570 ... ur-d-band/ ).

I have fitted FDs before and set this one exactly as per Shimano instructions. Having just spent the best part of 3 hours this pm working on this one I am now not sure it is compatible. The issue is that the only way I could get it to shift over to the big ring and for the inside face of the outer side of the cage not to rub on the chain (when in big ring and small sprocket i.e. top gear) I had to set the cable tension very very high. After my first few attempts I realised that if I pulled the cable by hand - after shifting up with the shifter - the FD would move further over. Until I pulled it by hand it had not moved far enough to touch the limit screw and clear the chain.

So I had to tighten the cable even more using the barrel adjustor when in big ring already. I had already pulled it as tight as I could when on small ring and setting it in the anchor bolt - but - I had to tighten it more via barrel adjustor - to get it to shift over far enough to reach the limit screw and clear the chain when in top gear. The problem then was that when cable was released via down shift at shifter to move to small ring it wouldn't move over far enough to rest on the low limit screw and the inner face of the inner side of the cage wouldn't clear the chain when in small front big rear (i.e. bottom gear). After much faffing and fuming I have now got it set so both extremes (top and bottom gears) both clear the chain but the tolerance is very very fine and the cable tension had to be very very precisely balanced for it to work.

My impression from reading had been that Shimano FDs were easier to set up and needed less fine tuning than SRAM - not my experience this time at all!

I am now wondering is this a symptom of this FD being incompatible with APEX shifters? I promise the alignment, limit screws etc were set correctly before this issue appeared. It was only when running up and down the range to settle the cable and give it (what I thought was) a final check over that it manifested. It really seems like maybe the APEX shifters are not pulling enough cable and so the FD doesn't move far enough at normal cable tensions and they correspondingly don't release enough cable for it to be able to spring back fully - but - from plenty previous posts I was sure they should be compatible! Any help advice as always gratefully received and if you need more info on the issue please ask.

OK - Since posting I have found out the 5700/5703 series 105 Group is not compatible with previous incarnations of Shimano Shifters so I reckon it must be that they have changed the pull in the 5700/5703 series and so while it was compatible with SRAM it ain't any more :cry: . Just bought a Force Mech so if anyone want an essentially unused 105 5700 mech let me know ...

Comments

  • amaferanga
    amaferanga Posts: 6,789
    I think you need a 5600 or earlier 105 front derailleur if you want to use it with SRAM shifters. I have that set up (5600 front derailleur with Apex shifters) on one bike and it works fine. Having said that though I've never had a problem with SRAM front derailleurs and I only have a Shimano one because that's what I had lying around when I built the bike up.
    More problems but still living....
  • Cheers amaferanga - someone had a new, unused, Force FD for sale on here and I picked it up so will post this 105 for sale and hopefully recoup some of my losses.