Forum home Road cycling forum Workshop

shifter and FD compatability

thebigmanthebigman Posts: 35
hi folks. I'm building up a flat bar bike from a friend and using most of the parts of a donor bike. it was running xt shifters with a 105 triple front mech and a mtb rear mech. This seemed to work ok'ish (i think) on her old setup, but i was wary about it. Ive fitted it to a planet x pro carbon frame and the FD is not working at all right, is this due to the different pull ratio on the shifter and mech?

Posts

  • me-109me-109 Posts: 1,439
    If it used to work but now doesn't it is most probably set-up issues.

    Is the cable secured to the mech on the correct side of the bolt, as that can affect the working quite a bit?

    Is it just the indexing that's the issue, or is the throw limited? Does it work across the range manually without a cable connected?
  • thebigmanthebigman Posts: 35
    i dont think its ever worked perfectly before as i can always remember her grumbling about it. ive tried attaching the cable from different angles and its still the same. 1 click on the shifter seems to shift the mech from the small inner to nearly the large outer, missing the middle ring. i was thinking of puting an mtb front mech on but think they are only suitable for around 42t outer chainrings and its got a 50.
  • me-109me-109 Posts: 1,439
    Try something like a Tourney. That should have a cage option for 'road-sized' chainrings.
  • darrell1967darrell1967 Posts: 364
    Hi,
    I’m building something similar but with a full Tiagra 2x10 groupset. I was told that everything must match to work properly.
  • lesfirthlesfirth Posts: 1,229
    If the xt shifter is off a mountain bike it will not work with a road front mech. The cable pull is not compatible. I have a similar project that came to a halt about a year ago. I could not find a mountain bike front mech to use with the shifter on the road bike frame I was using. There was not enough room between the seat tube and the tyre. The solution is road bike flat bar shifters ( Tiagra?).
    I was just trying to build a pub bike from spare bits.
  • darrell1967darrell1967 Posts: 364
    lesfirth said:

    If the xt shifter is off a mountain bike it will not work with a road front mech. The cable pull is not compatible. I have a similar project that came to a halt about a year ago. I could not find a mountain bike front mech to use with the shifter on the road bike frame I was using. There was not enough room between the seat tube and the tyre. The solution is road bike flat bar shifters ( Tiagra?).
    I was just trying to build a pub bike from spare bits.

    All I’ve got to buy for my bike now are the Tiagra shifters.
  • thebigmanthebigman Posts: 35
    thanks for all the replies. I too thought that this shouldn't work as the pull ratio's were different but i got it working flawlessly. If i fitted the cable into the mech with tension then it would 'over pull' as the pull ratio was different, but if i fitted it with some slack then it would shift to the right position. obviously this worked on my specific frame (planet x pro carbon) but may not on others. obviously the correct shifters would be the best way to go but had to use what i had..
  • PMarkPMark Posts: 92
    9 Speed MTB and road Shimano stuff is interchangeable, but 10 and 11 speed unfortunately isn't. That's why I like sticking to 9 speed on my road and mountain bikes, so I can use the same detailers, chains and cassettes on ether bike.
Sign In or Register to comment.