Sora 3503 FD (band version) hitting middle chainring

Unkle77
Unkle77 Posts: 32
edited March 2015 in Workshop
Hi,

I bought the Sora 3503 FD (band version) as I believe it is designed for my bikes chainset, 50/39/30, however after installing it it sits at least 4mm above the top chainring in order to only just clear the middle chainring. This has resulted in terrible shifting. If I drop it another mm, the derailleur hits the middle chainring. :?

I've tried looking at forum posts, youtube videos etc but obviously it "just works" for their set-up with the desired 2mm gap and smooth shifting.....

Any experience of this?

Cheers

Comments

  • jgsi
    jgsi Posts: 5,062
    Post a couple of clear pictures of the way it is now. Be a bit easier to spot anything incorrect.
    From the side/top/behind.
  • dj58
    dj58 Posts: 2,223
    What chainset and BB are you using, is the middle ring round or oval shaped? Something odd there if the FD cage is fouling the 39T ring when set to clear the 50T ring.
  • rafletcher
    rafletcher Posts: 1,235
    I had this trying to use an Ultegra triple mech on a 105 chain set. They were designed for different ring combinations - I think the Ultegra chain set had a 52 outer and the 105 a 50. Sounds like you have something similar. Only found this problem with Shimano :roll:
  • JayKosta
    JayKosta Posts: 635
    What shifting troubles are happening?
    Going from middle to big, or from big to middle?
    Are the shifts using small and middle OK?

    Perhaps the HIGH limit screw is not quite right.
    Does it shift OK when testing with bike off the ground, and trouble when actually riding?

    Jay Kosta
    Endwell NY USA
  • Unkle77
    Unkle77 Posts: 32
    I've not had a chance to take photos, I'll do that tomorrow.

    The BB is BB-UN55 Bottom Bracket (68-113mm version) the same as the original.
    The I cant remember the chainset manufacturer, I'll see if it is written on them tomorrow, they are 50/39/30T attached to Sugino Comp cranks. The middle ring is circular.

    Yeah I saw that there are different mechs for different chainsets and clearances, that's why this doesn't make any sense.

    I've set the high limit screw to not come into play atm.

    The problem is shifting, on any level really, high tension to get it to the middle, even more to try and get it to the top. Very slow to actually move up. Moving down is instant. The problem is under all conditions, up in the air and under force.
  • Unkle77
    Unkle77 Posts: 32
    edited January 2015
    I've counted the teeth on the large gear and it is indeed 50T, so I decided to count the teeth on the middle gear, 42T :? either Specialized decided to change the spec of their bike and not tell anyone or the shop I bought it off of decided to have some fun....

    So my question is what mech is best for this combo? One geared towards 52T or 50T? I presume 50T as that is what came with the bike....

    After some adjustment I took the bike for a ride to see if the shifting was any better while I'm riding, while shifting down from the large gear my STI broke :x I've taken it apart and the pawl has snapped and will not stay on its axle, so i now need to buy a new shifter :evil:

    Anyway, here are the images
  • Unkle77
    Unkle77 Posts: 32
    and some more...
  • Unkle77
    Unkle77 Posts: 32
    Any thoughts?

    Front mech for 52T or 50T? for a 50-42-30T? or buy a 39T?
  • desweller
    desweller Posts: 5,175
    I would have thought your middle ring is OK for that mech.

    If the force at the lever is too high then perhaps either the cable is clamped incorrectly or the mech needs a drop of oil in the pivots? Does it move freely if you operate it by hand?

    What shifters are you using, BTW?
    - - - - - - - - - -
    On Strava.{/url}
  • dj58
    dj58 Posts: 2,223
    How old is your bike, does the spec say it should have a 39T middle ring and have you been back to the shop and asked them to swop the 42T for a 39T?

Categories