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Compatible rear derailleurs for Tiagra 4700 shifters ?

hairy_boyhairy_boy Posts: 344
edited September 2018 in Workshop
My 10 speed Tiagra rear derailleur on my Giant Defy Advanced 3 has been playing up for a while.

Front shifters are Tiagra 4700.

Tried re-indexing a couple of times and also changed the gear cable but to no avail. Thinking I might try a new derailleur but read conflicting views on compatibility of 105 derailleurs with Tiagra 4700 shifters due to some weird pull ratio on the Tiagra shifters.

Anyone know if a 10 speed 105 rear derailleur will work with Tiagra 4700 shifters ?

Posts

  • keef66keef66 Posts: 13,286
    No, it won't. Confusingly 10 speed 4700 uses the same pull ratio as the 11 speed stuff. So you'd need either another 4700, or a 5800, R7000, 6800, R8000 etc

    But before you bin it, have you taken the mech off and given it a good clean and lube? And have you checked the alignment of the mech hanger?
  • Thanks Keef66,

    The hanger looks straight, I will try giving the current mech a good clean and lube and if not resolved will probably try a 5800 11sp 105 rear derailleur.

    I have a 11x32t rear cassette with 34/50 crank set and think my current mech is long cage. Any advantage to a long cage over a medium cage 5800 mech? the medium cage mech looks to be 28t - 32t compatible.
  • timothywtimothyw Posts: 2,482
    Hairy Boy wrote:
    if not resolved will probably try a 5800 11sp 105 rear derailleur.
    That won't work either.

    Get a Sora rear derailleur or find someone selling a 5700/4600/6700 etc derailleur.

    11 speed shimano and 4700 Tiagra derailleurs are not compatible with your shifters. Everything else is.... (road wise. MTB derailleurs you will have to go to 9 speed or lower...)
  • keef66keef66 Posts: 13,286
    They come in short cage (SS) and medium cage (GS)

    Officially the SS will take up to a 28t sprocket and the GS needs a largest sprocket 28-32t.

    Unofficially you may get a SS to work with a 30 or 32t sprocket by adjusting the B screw
  • keef66keef66 Posts: 13,286
    timothyw wrote:
    Hairy Boy wrote:
    if not resolved will probably try a 5800 11sp 105 rear derailleur.
    That won't work either.

    Get a Sora rear derailleur or find someone selling a 5700/4600/6700 etc derailleur.

    11 speed shimano and 4700 Tiagra derailleurs are not compatible with your shifters. Everything else is.... (road wise. MTB derailleurs you will have to go to 9 speed or lower...)

    Why would a 4700 rear derailleur not be compatible with the OP's 4700 shifters?? The numbering suggests to me that they may well have been designed to work together...
  • Rear 105 Mechs usually don't wear out until they've had mega miles, severe crud combined with total neglect or suffered physical damage. As mentioned, could be a bent hanger and eyeballing may not be enough, check with some type of gauge or tool. Also could be worn chain and/or cassette. You mentioned a new cable but are you sure that it's moving freely?
  • keef66keef66 Posts: 13,286
    Rear 105 Mechs usually don't wear out until they've had mega miles, severe crud combined with total neglect or suffered physical damage. As mentioned, could be a bent hanger and eyeballing may not be enough, check with some type of gauge or tool. Also could be worn chain and/or cassette. You mentioned a new cable but are you sure that it's moving freely?

    But it's a Tiagra rear mech...

    Am I the only one who actually read the OP properly??
  • dj58dj58 Posts: 2,074
    Just get another RD-4700 GS, will take a 28T, 30T, 32T or 34T low sprocket.
  • So the 105 5800-GS rear mech should work fine with my Tiagra 4700 shifters and 32t rear cassette then, yes ?

    I usually take the opportunity for a modest upgrade if buying replacement parts, so 105 instead of Tiagra kind of ticks the box for me as long as it will work ok.
  • keef66 wrote:
    But it's a Tiagra rear mech...
    Am I the only one who actually read the OP properly??

    Ooops, haven't had my coffee yet. Same advise applies for Tiagra though.
  • keef66keef66 Posts: 13,286
    Hairy Boy wrote:
    So the 105 5800-GS rear mech should work fine with my Tiagra 4700 shifters and 32t rear cassette then, yes ?

    I usually take the opportunity for a modest upgrade if buying replacement parts, so 105 instead of Tiagra kind of ticks the box for me as long as it will work ok.

    Yes, it will work.

    @Crankycrank - that's understandable, you're several time zones away too :D
  • Thanks a million for your advice keef66
  • timothywtimothyw Posts: 2,482
    Obviously it's been a long week already. :D

    Just buy a 4700 rear derailleur..... Why would you get anything else. This is probably what confused me.
  • keef66keef66 Posts: 13,286
    timothyw wrote:
    Obviously it's been a long week already. :D

    Just buy a 4700 rear derailleur..... Why would you get anything else. This is probably what confused me.

    :D
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