Swapping Tiagra shifters with 105 compatability?

small_bloke
small_bloke Posts: 222
edited April 2014 in Workshop
I want to swap my Tiagra shifters with 105 after crash damage. The cable routing on 105 is much neater as well.

Existing groupset is Tiagra. The shifters are Tiagra ST4600.
This is my bike....http://www.evanscycles.com/products/nor ... e-ec041208

Replace with 105 shifters FD5700
http://www.wiggle.co.uk/shimano-105-570 ... 5360416639

Will this work or will there be some compatability issues with the front and rear mech?

Comments

  • markhewitt1978
    markhewitt1978 Posts: 7,614
    If it's all 10 speed then it'll work fine. I've seen bikes sold as new with 105 levers and Tiagra front mech, for example.
  • me-109
    me-109 Posts: 1,915
    Should be fine, both ten speed.
  • dgunthor
    dgunthor Posts: 644
    the 5700 have the cables under the bar tape, yes. I find the older style without the cable under the bar tape shift better though. not sure if i'd see it as an upgrade.

    105 5800 11 speed is out in the summer - wait for that? or save your money and stick with what you have?

    might find a dura ace or ultegra rear mech (if you have a tiagra) plus some new shimano Sp-41 cable outer and polymer coated inner provides better shifting than changing the shifters
  • markhewitt1978
    markhewitt1978 Posts: 7,614
    Going 11 speed would mean pretty much changing all the other components. Not great really. He says he wants to change the shifters due to crash damage, not (just) for an upgrade.
  • dgunthor
    dgunthor Posts: 644
    oops, missed the crash damage bit
  • Prime586
    Prime586 Posts: 43
    Shimano increased the brake pull ratio slightly on the 5700 105 levers and calipers to match Ultegra and Dura Ace. I don't think it makes that much difference though - I use 105 levers and FSA Gossamer calipers and they seem to work OK.
  • Prime586 wrote:
    Shimano increased the brake pull ratio slightly on the 5700 105 levers and calipers to match Ultegra and Dura Ace. I don't think it makes that much difference though - I use 105 levers and FSA Gossamer calipers and they seem to work OK.

    What are the effects of increased brake pull ratio? I recently done up an old bike but kept my old 105 front shifter and the other one was replaced with a tiagra. My proper road bike has modern 105 stuff all round and the levers feel solid once the brakes bite. The brakes on my old bike dont feel solid although they are satisfactory.
  • Prime586
    Prime586 Posts: 43
    Prime586 wrote:
    Shimano increased the brake pull ratio slightly on the 5700 105 levers and calipers to match Ultegra and Dura Ace. I don't think it makes that much difference though - I use 105 levers and FSA Gossamer calipers and they seem to work OK.

    What are the effects of increased brake pull ratio? I recently done up an old bike but kept my old 105 front shifter and the other one was replaced with a tiagra. My proper road bike has modern 105 stuff all round and the levers feel solid once the brakes bite. The brakes on my old bike dont feel solid although they are satisfactory.

    I believe they increased the total cable pull and also changed the 'progression curve' of the pull (i.e. the cable pull rate relative to the position of the lever). The idea behind it was to make the brakes more progressive and easier to modulate (and to increase the sales of Shimano's brakes...), which is probably reflected in the brake feel you are getting on your new bike.

    When the newer levers are used with older brakes that use a shorter pull, it means they will contact the rim earlier in the pull, and as the 'curve' of the pull hasn't increased as much at that point you will need to exert more pressure on the lever than you normally would to get the full 'bite'. Some people have described this as leading to a bit of a wooden or dead feeling during braking, which I would probably agree with though changing to decent-quality pads helped improve things.