Ultegra front derailleur "not wide enough"

supercarl
supercarl Posts: 43
edited August 2009 in Workshop
Hello all,

Have just bought a madone 5.2 and have a problem in that when the chain is on the smallest 2 or largest 2 cogs on the rear gears, it rubs against the sides of the front shifter, which doesn't seem right.

I can adjust it via the limit stop screws to instead have the rubbing just on the smallest 4,but this is no help really!

One idea i've had is that it is perhaps that the front derailleur is designed for the 9 gear version, when I have the 10 spped ultegra?

Any suggestions? I really don't want to trouble LBS if its something I can fix. Thanks in advance

Comments

  • sorry - posted x2 in error, can a moderator delete please?
  • Steveorow
    Steveorow Posts: 162
    I assume youve checked the trim function ? There should be no difference in the 9 speed ot 10 speed as its not indexed . The STI pulls the gear cable a fixed ammount which cable moves the derailleur by a fixed ammont .
    Press the small black gear shifter half way until it clicks . This should move the derailleur slightly but not enough to cause a shift down ; this should stop the chain rubbing . Look on the shmano web site for setup instructions .
  • pinno
    pinno Posts: 51,784
    My 8 speed levers, if I remember rightly, had sufficent clicks so that you could adjust the front mech whilst you were on the big or small ring. My upgraded 10 speed is the same - there is at least 6 clicks from start to finish ( I don't actually know, I have'nt counted).

    I would: slacken off the front mech cable and click the lever all the way down. Adjust the lower limit screw so that you get no rubbing of the front mech whilst in first gear - adjust it so that there is the minimum of space required - between the front mech and the chain on the wheel side (the reason for this is clear if you want to experiment, but for the sake of explanation, I won't bother!).
    Slacken off the trim function.
    Once you have done this, tighten the cable bolt taking any residual slack out of the cables. Use the trim function (as suggested by steveoro) to acquire a reasonable movement of the front mech on the first click. If no movement, tighten the cable a fraction more. I think, the way you are describing the problem, either the cable is too tight to alllow the mech reach the end of its lower limit or the lower limit screw is mal adjusted. A cable that is too tight will in itself limit the extent the front mech goes (effectively) back towards the seat tube. An easy way to check this is - Does the Ergo lever click but at the same time there is no movement on the mech? Same for an over slack cable.
    Important: Make sure once you have done this to adjust the outer limit screw as well.

    Hope this helps.
    seanoconn - gruagach craic!
  • John.T
    John.T Posts: 3,698
    pinarello001. You must be on Campag. Different animal altogether. They just have a multi ratchet arrangment. Shimano are fully indexed with a trim facility.
  • spadey
    spadey Posts: 54
    have you tried checking to see if the FD has rotated on the frame. I recently found I had knocked it and spent ages fiddling with the cable to get rid of the rub when I realised the frame clamp was loose and it had moved on the frame!
  • pinno
    pinno Posts: 51,784
    John T >

    Explain trim facility ? I presume that you are talking about the downtube mounting trim screws? If that is the case, I bought the Dura Ace downtube mounts as the Dura ace has a very neat ratchet system for the rear mech on the down tube mounts - and admittedly, is better than the Campag. Its the only Shimano on my bike.

    If not enlighten me. yes, you are right - I am on Campag but Campag or not, the set up is the same for Shimano is'nt it? I mean with too slack/tight cables, limit screws etc - its the usual problem and I assumed this was so. For example every rear mech has trim screws on the back of the mech where the cable outer goes into the body, no?
    (just out of curiosity).

    Anyway, way back, somebloke convinced me to buy a Chorus Headset instead of the roughly equivalent Ultegra. It was a precious 6 quid more - which when you are young does not make any sense. Its now on a bike that was rebuilt as a retro - my old stel Battaglin, and the headset is still going, 19 years after I fiited it ! I am glad that bloke was in the shop at the time.
    seanoconn - gruagach craic!
  • John.T
    John.T Posts: 3,698
    Explain trim facility ? I presume that you are talking about the downtube mounting trim screws?
    No. I don't even know what they are. Do you mean the barrel adjusters for the cable. The trim facility is on the STI levers. It enables the cage to be moved in a small amount on the big ring and out a small amount on the inner one to prevent chain rub on extreme cross over. This is done by moving the relevent lever a half throw. A full throw will change the gear.
    It has nothing to do with the screws on the mechs which are to limit the overall travel of the mech.
    LH Campag Ergo levers do not use this system but have a series of clicks so you can stop the cage where you want too. I prefer the Shimano system but it must be set up correctly.
  • pinno
    pinno Posts: 51,784
    Definatly glad I bought Campag.

    So the Shimanooo sti LH lever is like a violin string gone a bit fancy.

    I see.Those clever Japs. So you don't get much 'click' for your money.
    seanoconn - gruagach craic!
  • on the road
    on the road Posts: 5,631
    supercarl wrote:
    Hello all,

    Have just bought a madone 5.2 and have a problem in that when the chain is on the smallest 2 or largest 2 cogs on the rear gears, it rubs against the sides of the front shifter, which doesn't seem right.
    Do you mean you have the chain on the small chainwheel and smallest rear cog, or large chainwheel and largest rear cog?

    You are not supposed to use those combinations, it will result in premature wear of the chain and maybe cassette. Also, those extreme angles mean that the chain will always rub on the front derailleur. That's a common mistake all beginners make.
  • John.T
    John.T Posts: 3,698
    supercarl wrote:
    Hello all,

    Have just bought a madone 5.2 and have a problem in that when the chain is on the smallest 2 or largest 2 cogs on the rear gears, it rubs against the sides of the front shifter, which doesn't seem right.
    Do you mean you have the chain on the small chainwheel and smallest rear cog, or large chainwheel and largest rear cog?

    You are not supposed to use those combinations, it will result in premature wear of the chain and maybe cassette. Also, those extreme angles mean that the chain will always rub on the front derailleur. That's a common mistake all beginners make.
    I agree that these combinations should be used sparingly but if set up right they can be without chin rub. My 5.2 is fine. I hardly ever use the trim.