fitting Shimano Ultegra front derailleur???

plaudax01
plaudax01 Posts: 7
edited September 2010 in Workshop
I've just replaced my broken Tiagra 9 speed front mech with a Shimano Ultegra 10 speed (as mine is a 10 speed cassette).
The instructions specify that the bottom edge of mech should clear the outer chain ring by 1mm. When I tried this I find the trailing end of the mech overlaps/comes into contact with the chain ring.
I've now got it set up and working but with about 5mm clearance.
My question is why does it specify 1mm clearance when this is impossible and does it matter so long as it changes OK?
Oh and it's a triple.

Comments

  • Ben6899
    Ben6899 Posts: 9,686
    Is the new derailleur the same shape as the old one? The new one might be for a compact chainset and hence have a smaller diameter than the old one and the outer ring.
    Ben

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  • keef66
    keef66 Posts: 13,123
    +1 on the double vs triple suggestion.

    I always think 1mm is just too close for comfort anyway, and set it up a bit higher. Shifting isn't quite as crisp, but I know the front mech isn't going to hit any teeth.
  • plaudax01
    plaudax01 Posts: 7
    Thanks for your comments.
    I don't think it's for a compact, the model no is FD6603BSM.
    It would be nice if Shimano had a technical support email contact you could field questions like this.
  • stokey1964
    stokey1964 Posts: 454
    I had this problem trying to get a 10 speed Ultegra triple fromt mech working with a 9 speed Ultegra triple chainset

    The cage would always catch the middle ring.

    I got it working "Sort of" but it was far from ideal. I found a second hand 9 speed triple mech and it was perfect.

    I believe they changed the sizes when they went from 9 to 10 speed.


    Simon
  • keef66
    keef66 Posts: 13,123
    The 6603 would seem to indicate it's for a triple. Maybe it's designed to work only with the matching chainrings? Wot chainset you got??
  • plaudax01
    plaudax01 Posts: 7
    I've got a 105 chainset. I originally ordered a 105 front mech but the shop didn't have it in stock so they agreed to send the Ultegra instead saying it would be fine with the 105 chainset. I needed it urgently so agreed.
  • plaudax01
    plaudax01 Posts: 7
    Seems to be sorted now. I took it to the bike shop and the man there said the 2mm gap applies when the mech is in the sprung back position ie not directly over the outer chainring. He did have to move it a bit higher though to stop it rubbing against the middle ring when the mech was over the outer ring.
    The main thing I've learnt here is that when you take your bike to the bike shop make sure you get the bloke who really knows what he's doing to have a look at it for you. Not the part time sales assistant who thinks he knows it all.

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